diff --git a/cameraserver/multiCameraServer/src/main/native/cpp/main.cpp b/cameraserver/multiCameraServer/src/main/native/cpp/main.cpp
index df408dee2a..a555984e02 100644
--- a/cameraserver/multiCameraServer/src/main/native/cpp/main.cpp
+++ b/cameraserver/multiCameraServer/src/main/native/cpp/main.cpp
@@ -4,10 +4,12 @@
 
 #include <cstdio>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <networktables/NetworkTableInstance.h>
-#include <wpi/StringRef.h>
+#include <wpi/StringExtras.h>
+#include <wpi/fmt/raw_ostream.h>
 #include <wpi/json.h>
 #include <wpi/raw_istream.h>
 #include <wpi/raw_ostream.h>
@@ -105,7 +107,7 @@ bool ReadConfig() {
   try {
     j = wpi::json::parse(is);
   } catch (const wpi::json::parse_error& e) {
-    ParseError() << "byte " << e.byte << ": " << e.what() << '\n';
+    fmt::print(ParseError(), "byte {}: {}\n", e.byte, e.what());
     return false;
   }
 
@@ -127,10 +129,9 @@ bool ReadConfig() {
   if (j.count("ntmode") != 0) {
     try {
       auto str = j.at("ntmode").get<std::string>();
-      wpi::StringRef s(str);
-      if (s.equals_lower("client")) {
+      if (wpi::equals_lower(str, "client")) {
         server = false;
-      } else if (s.equals_lower("server")) {
+      } else if (wpi::equals_lower(str, "server")) {
         server = true;
       } else {
         ParseError() << "could not understand ntmode value '" << str << "'\n";
@@ -156,8 +157,7 @@ bool ReadConfig() {
 }
 
 void StartCamera(const CameraConfig& config) {
-  wpi::outs() << "Starting camera '" << config.name << "' on " << config.path
-              << '\n';
+  fmt::print("Starting camera '{}' on {}\n", config.name, config.path);
   auto camera = frc::CameraServer::GetInstance()->StartAutomaticCapture(
       config.name, config.path);
 
@@ -178,10 +178,10 @@ int main(int argc, char* argv[]) {
   // start NetworkTables
   auto ntinst = nt::NetworkTableInstance::GetDefault();
   if (server) {
-    wpi::outs() << "Setting up NetworkTables server\n";
+    std::puts("Setting up NetworkTables server");
     ntinst.StartServer();
   } else {
-    wpi::outs() << "Setting up NetworkTables client for team " << team << '\n';
+    fmt::print("Setting up NetworkTables client for team {}\n", team);
     ntinst.StartClientTeam(team);
   }
 
diff --git a/cameraserver/src/main/native/cpp/cameraserver/CameraServer.cpp b/cameraserver/src/main/native/cpp/cameraserver/CameraServer.cpp
index 222753f991..19de47b9d0 100644
--- a/cameraserver/src/main/native/cpp/cameraserver/CameraServer.cpp
+++ b/cameraserver/src/main/native/cpp/cameraserver/CameraServer.cpp
@@ -7,14 +7,15 @@
 #include <atomic>
 #include <vector>
 
+#include <fmt/format.h>
 #include <networktables/NetworkTable.h>
 #include <networktables/NetworkTableInstance.h>
 #include <wpi/DenseMap.h>
 #include <wpi/ManagedStatic.h>
 #include <wpi/SmallString.h>
+#include <wpi/StringExtras.h>
 #include <wpi/StringMap.h>
 #include <wpi/mutex.h>
-#include <wpi/raw_ostream.h>
 
 #include "cameraserver/CameraServerShared.h"
 #include "ntcore_cpp.h"
@@ -56,20 +57,20 @@ CameraServer* CameraServer::GetInstance() {
   return &(*instance);
 }
 
-static wpi::StringRef MakeSourceValue(CS_Source source,
-                                      wpi::SmallVectorImpl<char>& buf) {
+static std::string_view MakeSourceValue(CS_Source source,
+                                        wpi::SmallVectorImpl<char>& buf) {
   CS_Status status = 0;
   buf.clear();
   switch (cs::GetSourceKind(source, &status)) {
     case CS_SOURCE_USB: {
-      wpi::StringRef prefix{"usb:"};
+      std::string_view prefix{"usb:"};
       buf.append(prefix.begin(), prefix.end());
       auto path = cs::GetUsbCameraPath(source, &status);
       buf.append(path.begin(), path.end());
       break;
     }
     case CS_SOURCE_HTTP: {
-      wpi::StringRef prefix{"ip:"};
+      std::string_view prefix{"ip:"};
       buf.append(prefix.begin(), prefix.end());
       auto urls = cs::GetHttpCameraUrls(source, &status);
       if (!urls.empty()) {
@@ -83,13 +84,11 @@ static wpi::StringRef MakeSourceValue(CS_Source source,
       return "unknown:";
   }
 
-  return wpi::StringRef{buf.begin(), buf.size()};
+  return {buf.begin(), buf.size()};
 }
 
-static std::string MakeStreamValue(const wpi::Twine& address, int port) {
-  return ("mjpg:http://" + address + wpi::Twine(':') + wpi::Twine(port) +
-          "/?action=stream")
-      .str();
+static std::string MakeStreamValue(std::string_view address, int port) {
+  return fmt::format("mjpg:http://{}:{}/?action=stream", address, port);
 }
 
 std::shared_ptr<nt::NetworkTable> CameraServer::Impl::GetSourceTable(
@@ -229,12 +228,8 @@ static std::string PixelFormatToString(int pixelFormat) {
 }
 
 static std::string VideoModeToString(const cs::VideoMode& mode) {
-  std::string rv;
-  wpi::raw_string_ostream oss{rv};
-  oss << mode.width << "x" << mode.height;
-  oss << " " << PixelFormatToString(mode.pixelFormat) << " ";
-  oss << mode.fps << " fps";
-  return oss.str();
+  return fmt::format("{}x{} {} {} fps", mode.width, mode.height,
+                     PixelFormatToString(mode.pixelFormat), mode.fps);
 }
 
 static std::vector<std::string> GetSourceModeValues(int source) {
@@ -248,23 +243,20 @@ static std::vector<std::string> GetSourceModeValues(int source) {
 
 static void PutSourcePropertyValue(nt::NetworkTable* table,
                                    const cs::VideoEvent& event, bool isNew) {
-  wpi::SmallString<64> name;
-  wpi::SmallString<64> infoName;
-  if (wpi::StringRef{event.name}.startswith("raw_")) {
-    name = "RawProperty/";
-    name += event.name;
-    infoName = "RawPropertyInfo/";
-    infoName += event.name;
+  std::string_view namePrefix;
+  std::string_view infoPrefix;
+  if (wpi::starts_with(event.name, "raw_")) {
+    namePrefix = "RawProperty";
+    infoPrefix = "RawPropertyInfo";
   } else {
-    name = "Property/";
-    name += event.name;
-    infoName = "PropertyInfo/";
-    infoName += event.name;
+    namePrefix = "Property";
+    infoPrefix = "PropertyInfo";
   }
 
   wpi::SmallString<64> buf;
   CS_Status status = 0;
-  nt::NetworkTableEntry entry = table->GetEntry(name);
+  nt::NetworkTableEntry entry =
+      table->GetEntry(fmt::format("{}/{}", namePrefix, event.name));
   switch (event.propertyKind) {
     case CS_PROP_BOOLEAN:
       if (isNew) {
@@ -277,13 +269,13 @@ static void PutSourcePropertyValue(nt::NetworkTable* table,
     case CS_PROP_ENUM:
       if (isNew) {
         entry.SetDefaultDouble(event.value);
-        table->GetEntry(infoName + "/min")
+        table->GetEntry(fmt::format("{}/{}/min", infoPrefix, event.name))
             .SetDouble(cs::GetPropertyMin(event.propertyHandle, &status));
-        table->GetEntry(infoName + "/max")
+        table->GetEntry(fmt::format("{}/{}/max", infoPrefix, event.name))
             .SetDouble(cs::GetPropertyMax(event.propertyHandle, &status));
-        table->GetEntry(infoName + "/step")
+        table->GetEntry(fmt::format("{}/{}/step", infoPrefix, event.name))
             .SetDouble(cs::GetPropertyStep(event.propertyHandle, &status));
-        table->GetEntry(infoName + "/default")
+        table->GetEntry(fmt::format("{}/{}/default", infoPrefix, event.name))
             .SetDouble(cs::GetPropertyDefault(event.propertyHandle, &status));
       } else {
         entry.SetDouble(event.value);
@@ -404,12 +396,11 @@ CameraServer::Impl::Impl() : m_nextPort(kBasePort) {
           case cs::VideoEvent::kSourcePropertyChoicesUpdated: {
             auto table = GetSourceTable(event.sourceHandle);
             if (table) {
-              wpi::SmallString<64> name{"PropertyInfo/"};
-              name += event.name;
-              name += "/choices";
               auto choices =
                   cs::GetEnumPropertyChoices(event.propertyHandle, &status);
-              table->GetEntry(name).SetStringArray(choices);
+              table
+                  ->GetEntry(fmt::format("PropertyInfo/{}/choices", event.name))
+                  .SetStringArray(choices);
             }
             break;
           }
@@ -433,35 +424,35 @@ CameraServer::Impl::Impl() : m_nextPort(kBasePort) {
   // else tries to change it.
   wpi::SmallString<64> buf;
   m_tableListener = nt::NetworkTableInstance::GetDefault().AddEntryListener(
-      kPublishName + wpi::Twine('/'),
+      fmt::format("{}/", kPublishName),
       [=](const nt::EntryNotification& event) {
-        wpi::StringRef relativeKey =
-            event.name.substr(wpi::StringRef(kPublishName).size() + 1);
+        auto relativeKey = wpi::drop_front(
+            event.name, std::string_view{kPublishName}.size() + 1);
 
         // get source (sourceName/...)
         auto subKeyIndex = relativeKey.find('/');
-        if (subKeyIndex == wpi::StringRef::npos) {
+        if (subKeyIndex == std::string_view::npos) {
           return;
         }
-        wpi::StringRef sourceName = relativeKey.slice(0, subKeyIndex);
+        auto sourceName = wpi::slice(relativeKey, 0, subKeyIndex);
         auto sourceIt = m_sources.find(sourceName);
         if (sourceIt == m_sources.end()) {
           return;
         }
 
         // get subkey
-        relativeKey = relativeKey.substr(subKeyIndex + 1);
+        relativeKey.remove_prefix(subKeyIndex + 1);
 
         // handle standard names
-        wpi::StringRef propName;
+        std::string_view propName;
         nt::NetworkTableEntry entry{event.entry};
         if (relativeKey == "mode") {
           // reset to current mode
           entry.SetString(VideoModeToString(sourceIt->second.GetVideoMode()));
           return;
-        } else if (relativeKey.startswith("Property/")) {
+        } else if (wpi::starts_with(relativeKey, "Property/")) {
           propName = relativeKey.substr(9);
-        } else if (relativeKey.startswith("RawProperty/")) {
+        } else if (wpi::starts_with(relativeKey, "RawProperty/")) {
           propName = relativeKey.substr(12);
         } else {
           return;  // ignore
@@ -501,14 +492,14 @@ cs::UsbCamera CameraServer::StartAutomaticCapture() {
 }
 
 cs::UsbCamera CameraServer::StartAutomaticCapture(int dev) {
-  cs::UsbCamera camera{"USB Camera " + wpi::Twine(dev), dev};
+  cs::UsbCamera camera{fmt::format("USB Camera {}", dev), dev};
   StartAutomaticCapture(camera);
   auto csShared = GetCameraServerShared();
   csShared->ReportUsbCamera(camera.GetHandle());
   return camera;
 }
 
-cs::UsbCamera CameraServer::StartAutomaticCapture(const wpi::Twine& name,
+cs::UsbCamera CameraServer::StartAutomaticCapture(std::string_view name,
                                                   int dev) {
   cs::UsbCamera camera{name, dev};
   StartAutomaticCapture(camera);
@@ -517,8 +508,8 @@ cs::UsbCamera CameraServer::StartAutomaticCapture(const wpi::Twine& name,
   return camera;
 }
 
-cs::UsbCamera CameraServer::StartAutomaticCapture(const wpi::Twine& name,
-                                                  const wpi::Twine& path) {
+cs::UsbCamera CameraServer::StartAutomaticCapture(std::string_view name,
+                                                  std::string_view path) {
   cs::UsbCamera camera{name, path};
   StartAutomaticCapture(camera);
   auto csShared = GetCameraServerShared();
@@ -526,7 +517,7 @@ cs::UsbCamera CameraServer::StartAutomaticCapture(const wpi::Twine& name,
   return camera;
 }
 
-cs::AxisCamera CameraServer::AddAxisCamera(const wpi::Twine& host) {
+cs::AxisCamera CameraServer::AddAxisCamera(std::string_view host) {
   return AddAxisCamera("Axis Camera", host);
 }
 
@@ -542,8 +533,8 @@ cs::AxisCamera CameraServer::AddAxisCamera(wpi::ArrayRef<std::string> hosts) {
   return AddAxisCamera("Axis Camera", hosts);
 }
 
-cs::AxisCamera CameraServer::AddAxisCamera(const wpi::Twine& name,
-                                           const wpi::Twine& host) {
+cs::AxisCamera CameraServer::AddAxisCamera(std::string_view name,
+                                           std::string_view host) {
   cs::AxisCamera camera{name, host};
   StartAutomaticCapture(camera);
   auto csShared = GetCameraServerShared();
@@ -551,7 +542,7 @@ cs::AxisCamera CameraServer::AddAxisCamera(const wpi::Twine& name,
   return camera;
 }
 
-cs::AxisCamera CameraServer::AddAxisCamera(const wpi::Twine& name,
+cs::AxisCamera CameraServer::AddAxisCamera(std::string_view name,
                                            const char* host) {
   cs::AxisCamera camera{name, host};
   StartAutomaticCapture(camera);
@@ -560,7 +551,7 @@ cs::AxisCamera CameraServer::AddAxisCamera(const wpi::Twine& name,
   return camera;
 }
 
-cs::AxisCamera CameraServer::AddAxisCamera(const wpi::Twine& name,
+cs::AxisCamera CameraServer::AddAxisCamera(std::string_view name,
                                            const std::string& host) {
   cs::AxisCamera camera{name, host};
   StartAutomaticCapture(camera);
@@ -569,7 +560,7 @@ cs::AxisCamera CameraServer::AddAxisCamera(const wpi::Twine& name,
   return camera;
 }
 
-cs::AxisCamera CameraServer::AddAxisCamera(const wpi::Twine& name,
+cs::AxisCamera CameraServer::AddAxisCamera(std::string_view name,
                                            wpi::ArrayRef<std::string> hosts) {
   cs::AxisCamera camera{name, hosts};
   StartAutomaticCapture(camera);
@@ -578,7 +569,7 @@ cs::AxisCamera CameraServer::AddAxisCamera(const wpi::Twine& name,
   return camera;
 }
 
-cs::MjpegServer CameraServer::AddSwitchedCamera(const wpi::Twine& name) {
+cs::MjpegServer CameraServer::AddSwitchedCamera(std::string_view name) {
   // create a dummy CvSource
   cs::CvSource source{name, cs::VideoMode::PixelFormat::kMJPEG, 160, 120, 30};
   cs::MjpegServer server = StartAutomaticCapture(source);
@@ -590,7 +581,7 @@ cs::MjpegServer CameraServer::AddSwitchedCamera(const wpi::Twine& name) {
 cs::MjpegServer CameraServer::StartAutomaticCapture(
     const cs::VideoSource& camera) {
   AddCamera(camera);
-  auto server = AddServer(wpi::Twine("serve_") + camera.GetName());
+  auto server = AddServer(fmt::format("serve_{}", camera.GetName()));
   server.SetSource(camera);
   return server;
 }
@@ -633,22 +624,20 @@ cs::CvSink CameraServer::GetVideo(const cs::VideoSource& camera) {
     }
   }
 
-  cs::CvSink newsink{name};
+  cs::CvSink newsink{name.str()};
   newsink.SetSource(camera);
   AddServer(newsink);
   return newsink;
 }
 
-cs::CvSink CameraServer::GetVideo(const wpi::Twine& name) {
-  wpi::SmallString<64> nameBuf;
-  wpi::StringRef nameStr = name.toStringRef(nameBuf);
+cs::CvSink CameraServer::GetVideo(std::string_view name) {
   cs::VideoSource source;
   {
     std::scoped_lock lock(m_impl->m_mutex);
-    auto it = m_impl->m_sources.find(nameStr);
+    auto it = m_impl->m_sources.find(name);
     if (it == m_impl->m_sources.end()) {
       auto csShared = GetCameraServerShared();
-      csShared->SetCameraServerError("could not find camera {}", nameStr);
+      csShared->SetCameraServerError("could not find camera {}", name);
       return cs::CvSink{};
     }
     source = it->second;
@@ -656,14 +645,14 @@ cs::CvSink CameraServer::GetVideo(const wpi::Twine& name) {
   return GetVideo(source);
 }
 
-cs::CvSource CameraServer::PutVideo(const wpi::Twine& name, int width,
+cs::CvSource CameraServer::PutVideo(std::string_view name, int width,
                                     int height) {
   cs::CvSource source{name, cs::VideoMode::kMJPEG, width, height, 30};
   StartAutomaticCapture(source);
   return source;
 }
 
-cs::MjpegServer CameraServer::AddServer(const wpi::Twine& name) {
+cs::MjpegServer CameraServer::AddServer(std::string_view name) {
   int port;
   {
     std::scoped_lock lock(m_impl->m_mutex);
@@ -672,7 +661,7 @@ cs::MjpegServer CameraServer::AddServer(const wpi::Twine& name) {
   return AddServer(name, port);
 }
 
-cs::MjpegServer CameraServer::AddServer(const wpi::Twine& name, int port) {
+cs::MjpegServer CameraServer::AddServer(std::string_view name, int port) {
   cs::MjpegServer server{name, port};
   AddServer(server);
   return server;
@@ -683,14 +672,13 @@ void CameraServer::AddServer(const cs::VideoSink& server) {
   m_impl->m_sinks.try_emplace(server.GetName(), server);
 }
 
-void CameraServer::RemoveServer(const wpi::Twine& name) {
+void CameraServer::RemoveServer(std::string_view name) {
   std::scoped_lock lock(m_impl->m_mutex);
-  wpi::SmallString<64> nameBuf;
-  m_impl->m_sinks.erase(name.toStringRef(nameBuf));
+  m_impl->m_sinks.erase(name);
 }
 
 cs::VideoSink CameraServer::GetServer() {
-  wpi::SmallString<64> name;
+  std::string name;
   {
     std::scoped_lock lock(m_impl->m_mutex);
     if (m_impl->m_primarySourceName.empty()) {
@@ -698,20 +686,18 @@ cs::VideoSink CameraServer::GetServer() {
       csShared->SetCameraServerError("no camera available");
       return cs::VideoSink{};
     }
-    name = "serve_";
-    name += m_impl->m_primarySourceName;
+    name = fmt::format("serve_{}", m_impl->m_primarySourceName);
   }
   return GetServer(name);
 }
 
-cs::VideoSink CameraServer::GetServer(const wpi::Twine& name) {
+cs::VideoSink CameraServer::GetServer(std::string_view name) {
   wpi::SmallString<64> nameBuf;
-  wpi::StringRef nameStr = name.toStringRef(nameBuf);
   std::scoped_lock lock(m_impl->m_mutex);
-  auto it = m_impl->m_sinks.find(nameStr);
+  auto it = m_impl->m_sinks.find(name);
   if (it == m_impl->m_sinks.end()) {
     auto csShared = GetCameraServerShared();
-    csShared->SetCameraServerError("could not find server {}", nameStr);
+    csShared->SetCameraServerError("could not find server {}", name);
     return cs::VideoSink{};
   }
   return it->second;
@@ -726,10 +712,9 @@ void CameraServer::AddCamera(const cs::VideoSource& camera) {
   m_impl->m_sources.try_emplace(name, camera);
 }
 
-void CameraServer::RemoveCamera(const wpi::Twine& name) {
+void CameraServer::RemoveCamera(std::string_view name) {
   std::scoped_lock lock(m_impl->m_mutex);
-  wpi::SmallString<64> nameBuf;
-  m_impl->m_sources.erase(name.toStringRef(nameBuf));
+  m_impl->m_sources.erase(name);
 }
 
 void CameraServer::SetSize(int size) {
diff --git a/cameraserver/src/main/native/include/cameraserver/CameraServer.h b/cameraserver/src/main/native/include/cameraserver/CameraServer.h
index ce620ed1b8..e5ce45766f 100644
--- a/cameraserver/src/main/native/include/cameraserver/CameraServer.h
+++ b/cameraserver/src/main/native/include/cameraserver/CameraServer.h
@@ -8,9 +8,9 @@
 
 #include <memory>
 #include <string>
+#include <string_view>
 
 #include <wpi/ArrayRef.h>
-#include <wpi/Twine.h>
 
 #include "cscore.h"
 #include "cscore_cv.h"
@@ -63,7 +63,7 @@ class CameraServer {
    * @param name The name to give the camera
    * @param dev  The device number of the camera interface
    */
-  cs::UsbCamera StartAutomaticCapture(const wpi::Twine& name, int dev);
+  cs::UsbCamera StartAutomaticCapture(std::string_view name, int dev);
 
   /**
    * Start automatically capturing images to send to the dashboard.
@@ -71,8 +71,8 @@ class CameraServer {
    * @param name The name to give the camera
    * @param path The device path (e.g. "/dev/video0") of the camera
    */
-  cs::UsbCamera StartAutomaticCapture(const wpi::Twine& name,
-                                      const wpi::Twine& path);
+  cs::UsbCamera StartAutomaticCapture(std::string_view name,
+                                      std::string_view path);
 
   /**
    * Start automatically capturing images to send to the dashboard from
@@ -89,7 +89,7 @@ class CameraServer {
    *
    * @param host Camera host IP or DNS name (e.g. "10.x.y.11")
    */
-  cs::AxisCamera AddAxisCamera(const wpi::Twine& host);
+  cs::AxisCamera AddAxisCamera(std::string_view host);
 
   /**
    * Adds an Axis IP camera.
@@ -134,7 +134,7 @@ class CameraServer {
    * @param name The name to give the camera
    * @param host Camera host IP or DNS name (e.g. "10.x.y.11")
    */
-  cs::AxisCamera AddAxisCamera(const wpi::Twine& name, const wpi::Twine& host);
+  cs::AxisCamera AddAxisCamera(std::string_view name, std::string_view host);
 
   /**
    * Adds an Axis IP camera.
@@ -142,7 +142,7 @@ class CameraServer {
    * @param name The name to give the camera
    * @param host Camera host IP or DNS name (e.g. "10.x.y.11")
    */
-  cs::AxisCamera AddAxisCamera(const wpi::Twine& name, const char* host);
+  cs::AxisCamera AddAxisCamera(std::string_view name, const char* host);
 
   /**
    * Adds an Axis IP camera.
@@ -150,7 +150,7 @@ class CameraServer {
    * @param name The name to give the camera
    * @param host Camera host IP or DNS name (e.g. "10.x.y.11")
    */
-  cs::AxisCamera AddAxisCamera(const wpi::Twine& name, const std::string& host);
+  cs::AxisCamera AddAxisCamera(std::string_view name, const std::string& host);
 
   /**
    * Adds an Axis IP camera.
@@ -158,7 +158,7 @@ class CameraServer {
    * @param name The name to give the camera
    * @param hosts Array of Camera host IPs/DNS names
    */
-  cs::AxisCamera AddAxisCamera(const wpi::Twine& name,
+  cs::AxisCamera AddAxisCamera(std::string_view name,
                                wpi::ArrayRef<std::string> hosts);
 
   /**
@@ -168,7 +168,7 @@ class CameraServer {
    * @param hosts Array of Camera host IPs/DNS names
    */
   template <typename T>
-  cs::AxisCamera AddAxisCamera(const wpi::Twine& name,
+  cs::AxisCamera AddAxisCamera(std::string_view name,
                                std::initializer_list<T> hosts);
 
   /**
@@ -177,7 +177,7 @@ class CameraServer {
    * VideoSource.  Calling SetSource() on the returned object can be used
    * to switch the actual source of the stream.
    */
-  cs::MjpegServer AddSwitchedCamera(const wpi::Twine& name);
+  cs::MjpegServer AddSwitchedCamera(std::string_view name);
 
   /**
    * Get OpenCV access to the primary camera feed.  This allows you to
@@ -202,7 +202,7 @@ class CameraServer {
    *
    * @param name Camera name
    */
-  cs::CvSink GetVideo(const wpi::Twine& name);
+  cs::CvSink GetVideo(std::string_view name);
 
   /**
    * Create a MJPEG stream with OpenCV input. This can be called to pass custom
@@ -212,21 +212,21 @@ class CameraServer {
    * @param width Width of the image being sent
    * @param height Height of the image being sent
    */
-  cs::CvSource PutVideo(const wpi::Twine& name, int width, int height);
+  cs::CvSource PutVideo(std::string_view name, int width, int height);
 
   /**
    * Adds a MJPEG server at the next available port.
    *
    * @param name Server name
    */
-  cs::MjpegServer AddServer(const wpi::Twine& name);
+  cs::MjpegServer AddServer(std::string_view name);
 
   /**
    * Adds a MJPEG server.
    *
    * @param name Server name
    */
-  cs::MjpegServer AddServer(const wpi::Twine& name, int port);
+  cs::MjpegServer AddServer(std::string_view name, int port);
 
   /**
    * Adds an already created server.
@@ -240,7 +240,7 @@ class CameraServer {
    *
    * @param name Server name
    */
-  void RemoveServer(const wpi::Twine& name);
+  void RemoveServer(std::string_view name);
 
   /**
    * Get server for the primary camera feed.
@@ -255,7 +255,7 @@ class CameraServer {
    *
    * @param name Server name
    */
-  cs::VideoSink GetServer(const wpi::Twine& name);
+  cs::VideoSink GetServer(std::string_view name);
 
   /**
    * Adds an already created camera.
@@ -269,7 +269,7 @@ class CameraServer {
    *
    * @param name Camera name
    */
-  void RemoveCamera(const wpi::Twine& name);
+  void RemoveCamera(std::string_view name);
 
   /**
    * Sets the size of the image to use. Use the public kSize constants to set
diff --git a/cameraserver/src/main/native/include/cameraserver/CameraServer.inc b/cameraserver/src/main/native/include/cameraserver/CameraServer.inc
index bdd35508ed..8c8ec21cf9 100644
--- a/cameraserver/src/main/native/include/cameraserver/CameraServer.inc
+++ b/cameraserver/src/main/native/include/cameraserver/CameraServer.inc
@@ -19,7 +19,7 @@ inline cs::AxisCamera CameraServer::AddAxisCamera(
 
 template <typename T>
 inline cs::AxisCamera CameraServer::AddAxisCamera(
-    const wpi::Twine& name, std::initializer_list<T> hosts) {
+    std::string_view name, std::initializer_list<T> hosts) {
   std::vector<std::string> vec;
   vec.reserve(hosts.size());
   for (const auto& host : hosts) {
diff --git a/cmake/scripts/GenResource.cmake b/cmake/scripts/GenResource.cmake
index d28e5648e3..3c6e2515e2 100644
--- a/cmake/scripts/GenResource.cmake
+++ b/cmake/scripts/GenResource.cmake
@@ -7,7 +7,7 @@ GET_FILENAME_COMPONENT(inputBase ${input} NAME)
 STRING(REGEX REPLACE "[^a-zA-Z0-9]" "_" funcName "${inputBase}")
 SET(funcName "GetResource_${funcName}")
 
-FILE(WRITE "${output}" "#include <stddef.h>\n#include <wpi/StringRef.h>\nextern \"C\" {\nstatic const unsigned char contents[] = {")
+FILE(WRITE "${output}" "#include <stddef.h>\n#include <string_view>\nextern \"C\" {\nstatic const unsigned char contents[] = {")
 
 STRING(REGEX MATCHALL ".." outputData "${fileHex}")
 STRING(REGEX REPLACE ";" ", 0x" outputData "${outputData}")
@@ -17,7 +17,7 @@ FILE(APPEND "${output}" "const unsigned char* ${prefix}${funcName}(size_t* len)
 IF(NOT namespace STREQUAL "")
   FILE(APPEND "${output}" "namespace ${namespace} {\n")
 ENDIF()
-FILE(APPEND "${output}" "wpi::StringRef ${funcName}() {\n  return wpi::StringRef(reinterpret_cast<const char*>(contents), ${fileSize});\n}\n")
+FILE(APPEND "${output}" "std::string_view ${funcName}() {\n  return std::string_view(reinterpret_cast<const char*>(contents), ${fileSize});\n}\n")
 IF(NOT namespace STREQUAL "")
   FILE(APPEND "${output}" "}\n")
 ENDIF()
diff --git a/cscore/.styleguide b/cscore/.styleguide
index fada841611..f0732e1bf8 100644
--- a/cscore/.styleguide
+++ b/cscore/.styleguide
@@ -31,6 +31,7 @@ repoRootNameOverride {
 }
 
 includeOtherLibs {
+  ^fmt/
   ^opencv2/
   ^support/
   ^tcpsockets/
diff --git a/cscore/examples/enum_usb/enum_usb.cpp b/cscore/examples/enum_usb/enum_usb.cpp
index a5b7a10702..e9c1225a8c 100644
--- a/cscore/examples/enum_usb/enum_usb.cpp
+++ b/cscore/examples/enum_usb/enum_usb.cpp
@@ -2,83 +2,77 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
-#include <wpi/SmallString.h>
-#include <wpi/raw_ostream.h>
+#include <cstdio>
+
+#include <fmt/format.h>
 
 #include "cscore.h"
 
 int main() {
   CS_Status status = 0;
-  wpi::SmallString<64> buf;
 
   for (const auto& caminfo : cs::EnumerateUsbCameras(&status)) {
-    wpi::outs() << caminfo.dev << ": " << caminfo.path << " (" << caminfo.name
-                << ")\n";
+    fmt::print("{}: {} ({})\n", caminfo.dev, caminfo.path, caminfo.name);
     if (!caminfo.otherPaths.empty()) {
-      wpi::outs() << "Other device paths:\n";
+      std::puts("Other device paths:");
       for (auto&& path : caminfo.otherPaths) {
-        wpi::outs() << "  " << path << '\n';
+        fmt::print("  {}\n", path);
       }
     }
 
     cs::UsbCamera camera{"usbcam", caminfo.dev};
 
-    wpi::outs() << "Properties:\n";
+    std::puts("Properties:");
     for (const auto& prop : camera.EnumerateProperties()) {
-      wpi::outs() << "  " << prop.GetName();
+      fmt::print("  {}", prop.GetName());
       switch (prop.GetKind()) {
         case cs::VideoProperty::kBoolean:
-          wpi::outs() << " (bool): "
-                      << "value=" << prop.Get()
-                      << " default=" << prop.GetDefault();
+          fmt::print(" (bool): value={} default={}", prop.Get(),
+                     prop.GetDefault());
           break;
         case cs::VideoProperty::kInteger:
-          wpi::outs() << " (int): "
-                      << "value=" << prop.Get() << " min=" << prop.GetMin()
-                      << " max=" << prop.GetMax() << " step=" << prop.GetStep()
-                      << " default=" << prop.GetDefault();
+          fmt::print(" (int): value={} min={} max={} step={} default={}",
+                     prop.Get(), prop.GetMin(), prop.GetMax(), prop.GetStep(),
+                     prop.GetDefault());
           break;
         case cs::VideoProperty::kString:
-          wpi::outs() << " (string): " << prop.GetString(buf);
+          fmt::print(" (string): {}", prop.GetString());
           break;
         case cs::VideoProperty::kEnum: {
-          wpi::outs() << " (enum): "
-                      << "value=" << prop.Get();
+          fmt::print(" (enum): value={}", prop.Get());
           auto choices = prop.GetChoices();
           for (size_t i = 0; i < choices.size(); ++i) {
-            if (choices[i].empty()) {
-              continue;
+            if (!choices[i].empty()) {
+              fmt::print("\n    {}: {}", i, choices[i]);
             }
-            wpi::outs() << "\n    " << i << ": " << choices[i];
           }
           break;
         }
         default:
           break;
       }
-      wpi::outs() << '\n';
+      std::fputc('\n', stdout);
     }
 
-    wpi::outs() << "Video Modes:\n";
+    std::puts("Video Modes:");
     for (const auto& mode : camera.EnumerateVideoModes()) {
-      wpi::outs() << "  PixelFormat:";
+      const char* pixelFormat;
       switch (mode.pixelFormat) {
         case cs::VideoMode::kMJPEG:
-          wpi::outs() << "MJPEG";
+          pixelFormat = "MJPEG";
           break;
         case cs::VideoMode::kYUYV:
-          wpi::outs() << "YUYV";
+          pixelFormat = "YUYV";
           break;
         case cs::VideoMode::kRGB565:
-          wpi::outs() << "RGB565";
+          pixelFormat = "RGB565";
           break;
         default:
-          wpi::outs() << "Unknown";
+          pixelFormat = "Unknown";
           break;
       }
-      wpi::outs() << " Width:" << mode.width;
-      wpi::outs() << " Height:" << mode.height;
-      wpi::outs() << " FPS:" << mode.fps << '\n';
+      fmt::print("  PixelFormat:{} Width:{} Height:{} FPS:{}\n", pixelFormat,
+                 mode.width, mode.height, mode.fps);
     }
   }
 }
diff --git a/cscore/examples/settings/settings.cpp b/cscore/examples/settings/settings.cpp
index 7681d17121..40961b45ea 100644
--- a/cscore/examples/settings/settings.cpp
+++ b/cscore/examples/settings/settings.cpp
@@ -3,23 +3,27 @@
 // the WPILib BSD license file in the root directory of this project.
 
 #include <chrono>
+#include <cstdio>
 #include <thread>
 
-#include <wpi/SmallString.h>
-#include <wpi/raw_ostream.h>
+#include <fmt/format.h>
+#include <wpi/StringExtras.h>
 
 #include "cscore.h"
 
 int main(int argc, char** argv) {
   if (argc < 2) {
-    wpi::errs() << "Usage: settings camera [prop val] ... -- [prop val]...\n";
-    wpi::errs() << "  Example: settings 1 brightness 30 raw_contrast 10\n";
+    std::fputs("Usage: settings camera [prop val] ... -- [prop val]...\n",
+               stderr);
+    std::fputs("  Example: settings 1 brightness 30 raw_contrast 10\n", stderr);
     return 1;
   }
 
   int id;
-  if (wpi::StringRef{argv[1]}.getAsInteger(10, id)) {
-    wpi::errs() << "Expected number for camera\n";
+  if (auto v = wpi::parse_integer<int>(argv[1], 10)) {
+    id = v.value();
+  } else {
+    std::fputs("Expected number for camera\n", stderr);
     return 2;
   }
 
@@ -27,22 +31,21 @@ int main(int argc, char** argv) {
 
   // Set prior to connect
   int arg = 2;
-  wpi::StringRef propName;
-  for (; arg < argc && wpi::StringRef{argv[arg]} != "--"; ++arg) {
+  std::string_view propName;
+  for (; arg < argc && std::string_view{argv[arg]} != "--"; ++arg) {
     if (propName.empty()) {
       propName = argv[arg];
     } else {
-      wpi::StringRef propVal{argv[arg]};
-      int intVal;
-      if (propVal.getAsInteger(10, intVal)) {
-        camera.GetProperty(propName).SetString(propVal);
+      std::string_view propVal{argv[arg]};
+      if (auto v = wpi::parse_integer<int>(propVal, 10)) {
+        camera.GetProperty(propName).Set(v.value());
       } else {
-        camera.GetProperty(propName).Set(intVal);
+        camera.GetProperty(propName).SetString(propVal);
       }
-      propName = wpi::StringRef{};
+      propName = {};
     }
   }
-  if (arg < argc && wpi::StringRef{argv[arg]} == "--") {
+  if (arg < argc && std::string_view{argv[arg]} == "--") {
     ++arg;
   }
 
@@ -52,57 +55,51 @@ int main(int argc, char** argv) {
   }
 
   // Set rest
-  propName = wpi::StringRef{};
+  propName = {};
   for (; arg < argc; ++arg) {
     if (propName.empty()) {
       propName = argv[arg];
     } else {
-      wpi::StringRef propVal{argv[arg]};
-      int intVal;
-      if (propVal.getAsInteger(10, intVal)) {
-        camera.GetProperty(propName).SetString(propVal);
+      std::string_view propVal{argv[arg]};
+      if (auto v = wpi::parse_integer<int>(propVal, 10)) {
+        camera.GetProperty(propName).Set(v.value());
       } else {
-        camera.GetProperty(propName).Set(intVal);
+        camera.GetProperty(propName).SetString(propVal);
       }
-      propName = wpi::StringRef{};
+      propName = {};
     }
   }
 
   // Print settings
-  wpi::SmallString<64> buf;
-  wpi::outs() << "Properties:\n";
+  std::puts("Properties:");
   for (const auto& prop : camera.EnumerateProperties()) {
-    wpi::outs() << "  " << prop.GetName();
+    fmt::print("  {}", prop.GetName());
     switch (prop.GetKind()) {
       case cs::VideoProperty::kBoolean:
-        wpi::outs() << " (bool): "
-                    << "value=" << prop.Get()
-                    << " default=" << prop.GetDefault();
+        fmt::print(" (bool): value={} default={}", prop.Get(),
+                   prop.GetDefault());
         break;
       case cs::VideoProperty::kInteger:
-        wpi::outs() << " (int): "
-                    << "value=" << prop.Get() << " min=" << prop.GetMin()
-                    << " max=" << prop.GetMax() << " step=" << prop.GetStep()
-                    << " default=" << prop.GetDefault();
+        fmt::print(" (int): value={} min={} max={} step={} default={}",
+                   prop.Get(), prop.GetMin(), prop.GetMax(), prop.GetStep(),
+                   prop.GetDefault());
         break;
       case cs::VideoProperty::kString:
-        wpi::outs() << " (string): " << prop.GetString(buf);
+        fmt::print(" (string): {}", prop.GetString());
         break;
       case cs::VideoProperty::kEnum: {
-        wpi::outs() << " (enum): "
-                    << "value=" << prop.Get();
+        fmt::print(" (enum): value={}", prop.Get());
         auto choices = prop.GetChoices();
         for (size_t i = 0; i < choices.size(); ++i) {
-          if (choices[i].empty()) {
-            continue;
+          if (!choices[i].empty()) {
+            fmt::print("\n    {}: {}", i, choices[i]);
           }
-          wpi::outs() << "\n    " << i << ": " << choices[i];
         }
         break;
       }
       default:
         break;
     }
-    wpi::outs() << '\n';
+    std::fputc('\n', stdout);
   }
 }
diff --git a/cscore/examples/usbstream/usbstream.cpp b/cscore/examples/usbstream/usbstream.cpp
index f4a612e1e2..7a57e8d9a3 100644
--- a/cscore/examples/usbstream/usbstream.cpp
+++ b/cscore/examples/usbstream/usbstream.cpp
@@ -4,15 +4,15 @@
 
 #include <cstdio>
 
-#include <wpi/raw_ostream.h>
+#include <fmt/format.h>
 
 #include "cscore.h"
 
 int main() {
-  wpi::outs() << "hostname: " << cs::GetHostname() << '\n';
-  wpi::outs() << "IPv4 network addresses:\n";
+  fmt::print("hostname: {}\n", cs::GetHostname());
+  std::puts("IPv4 network addresses:");
   for (const auto& addr : cs::GetNetworkInterfaces()) {
-    wpi::outs() << "  " << addr << '\n';
+    fmt::print("  {}\n", addr);
   }
   cs::UsbCamera camera{"usbcam", 0};
   camera.SetVideoMode(cs::VideoMode::kMJPEG, 320, 240, 30);
@@ -22,9 +22,8 @@ int main() {
   CS_Status status = 0;
   cs::AddListener(
       [&](const cs::RawEvent& event) {
-        wpi::outs() << "FPS=" << camera.GetActualFPS()
-                    << " MBPS=" << (camera.GetActualDataRate() / 1000000.0)
-                    << '\n';
+        fmt::print("FPS={} MBPS={}\n", camera.GetActualFPS(),
+                   (camera.GetActualDataRate() / 1000000.0));
       },
       cs::RawEvent::kTelemetryUpdated, false, &status);
   cs::SetTelemetryPeriod(1.0);
diff --git a/cscore/examples/usbviewer/usbviewer.cpp b/cscore/examples/usbviewer/usbviewer.cpp
index 1b2ef5d44e..5c2e7c94c4 100644
--- a/cscore/examples/usbviewer/usbviewer.cpp
+++ b/cscore/examples/usbviewer/usbviewer.cpp
@@ -6,12 +6,13 @@
 #include <thread>
 #include <vector>
 
+#include <fmt/format.h>
+
 #define IMGUI_DEFINE_MATH_OPERATORS
 #include <imgui.h>
 #include <imgui_internal.h>
 #include <opencv2/core/core.hpp>
 #include <opencv2/imgproc.hpp>
-#include <wpi/raw_ostream.h>
 #include <wpi/spinlock.h>
 #include <wpigui.h>
 
@@ -38,7 +39,7 @@ int main() {
       // get frame from camera
       uint64_t time = cvsink.GrabFrame(frame);
       if (time == 0) {
-        wpi::outs() << "error: " << cvsink.GetError() << '\n';
+        fmt::print("error: {}\n", cvsink.GetError());
         continue;
       }
 
diff --git a/cscore/src/main/native/cpp/ConfigurableSourceImpl.cpp b/cscore/src/main/native/cpp/ConfigurableSourceImpl.cpp
index 6dedd33494..78cd988640 100644
--- a/cscore/src/main/native/cpp/ConfigurableSourceImpl.cpp
+++ b/cscore/src/main/native/cpp/ConfigurableSourceImpl.cpp
@@ -13,7 +13,7 @@
 
 using namespace cs;
 
-ConfigurableSourceImpl::ConfigurableSourceImpl(const wpi::Twine& name,
+ConfigurableSourceImpl::ConfigurableSourceImpl(std::string_view name,
                                                wpi::Logger& logger,
                                                Notifier& notifier,
                                                Telemetry& telemetry,
@@ -50,11 +50,11 @@ void ConfigurableSourceImpl::NumSinksEnabledChanged() {
   // ignore
 }
 
-void ConfigurableSourceImpl::NotifyError(const wpi::Twine& msg) {
+void ConfigurableSourceImpl::NotifyError(std::string_view msg) {
   PutError(msg, wpi::Now());
 }
 
-int ConfigurableSourceImpl::CreateProperty(const wpi::Twine& name,
+int ConfigurableSourceImpl::CreateProperty(std::string_view name,
                                            CS_PropertyKind kind, int minimum,
                                            int maximum, int step,
                                            int defaultValue, int value) {
@@ -75,12 +75,12 @@ int ConfigurableSourceImpl::CreateProperty(const wpi::Twine& name,
         value = prop.value;
       });
   m_notifier.NotifySourceProperty(*this, CS_SOURCE_PROPERTY_CREATED, name, ndx,
-                                  kind, value, wpi::Twine{});
+                                  kind, value, {});
   return ndx;
 }
 
 int ConfigurableSourceImpl::CreateProperty(
-    const wpi::Twine& name, CS_PropertyKind kind, int minimum, int maximum,
+    std::string_view name, CS_PropertyKind kind, int minimum, int maximum,
     int step, int defaultValue, int value,
     std::function<void(CS_Property property)> onChange) {
   // TODO
@@ -102,5 +102,5 @@ void ConfigurableSourceImpl::SetEnumPropertyChoices(
   prop->enumChoices = choices;
   m_notifier.NotifySourceProperty(*this, CS_SOURCE_PROPERTY_CHOICES_UPDATED,
                                   prop->name, property, CS_PROP_ENUM,
-                                  prop->value, wpi::Twine{});
+                                  prop->value, {});
 }
diff --git a/cscore/src/main/native/cpp/ConfigurableSourceImpl.h b/cscore/src/main/native/cpp/ConfigurableSourceImpl.h
index 9dcb3177fe..bfc07f903e 100644
--- a/cscore/src/main/native/cpp/ConfigurableSourceImpl.h
+++ b/cscore/src/main/native/cpp/ConfigurableSourceImpl.h
@@ -9,10 +9,10 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <wpi/ArrayRef.h>
-#include <wpi/Twine.h>
 
 #include "SourceImpl.h"
 
@@ -20,7 +20,7 @@ namespace cs {
 
 class ConfigurableSourceImpl : public SourceImpl {
  protected:
-  ConfigurableSourceImpl(const wpi::Twine& name, wpi::Logger& logger,
+  ConfigurableSourceImpl(std::string_view name, wpi::Logger& logger,
                          Notifier& notifier, Telemetry& telemetry,
                          const VideoMode& mode);
 
@@ -35,10 +35,10 @@ class ConfigurableSourceImpl : public SourceImpl {
   void NumSinksEnabledChanged() override;
 
   // OpenCV-specific functions
-  void NotifyError(const wpi::Twine& msg);
-  int CreateProperty(const wpi::Twine& name, CS_PropertyKind kind, int minimum,
+  void NotifyError(std::string_view msg);
+  int CreateProperty(std::string_view name, CS_PropertyKind kind, int minimum,
                      int maximum, int step, int defaultValue, int value);
-  int CreateProperty(const wpi::Twine& name, CS_PropertyKind kind, int minimum,
+  int CreateProperty(std::string_view name, CS_PropertyKind kind, int minimum,
                      int maximum, int step, int defaultValue, int value,
                      std::function<void(CS_Property property)> onChange);
   void SetEnumPropertyChoices(int property, wpi::ArrayRef<std::string> choices,
diff --git a/cscore/src/main/native/cpp/CvSinkImpl.cpp b/cscore/src/main/native/cpp/CvSinkImpl.cpp
index 8154b4b4f6..dbda6c61e7 100644
--- a/cscore/src/main/native/cpp/CvSinkImpl.cpp
+++ b/cscore/src/main/native/cpp/CvSinkImpl.cpp
@@ -18,14 +18,14 @@
 
 using namespace cs;
 
-CvSinkImpl::CvSinkImpl(const wpi::Twine& name, wpi::Logger& logger,
+CvSinkImpl::CvSinkImpl(std::string_view name, wpi::Logger& logger,
                        Notifier& notifier, Telemetry& telemetry)
     : SinkImpl{name, logger, notifier, telemetry} {
   m_active = true;
   // m_thread = std::thread(&CvSinkImpl::ThreadMain, this);
 }
 
-CvSinkImpl::CvSinkImpl(const wpi::Twine& name, wpi::Logger& logger,
+CvSinkImpl::CvSinkImpl(std::string_view name, wpi::Logger& logger,
                        Notifier& notifier, Telemetry& telemetry,
                        std::function<void(uint64_t time)> processFrame)
     : SinkImpl{name, logger, notifier, telemetry} {}
@@ -110,7 +110,7 @@ void CvSinkImpl::ThreadMain() {
       std::this_thread::sleep_for(std::chrono::seconds(1));
       continue;
     }
-    SDEBUG4("waiting for frame");
+    SDEBUG4("{}", "waiting for frame");
     Frame frame = source->GetNextFrame();  // blocks
     if (!m_active) {
       break;
@@ -127,14 +127,14 @@ void CvSinkImpl::ThreadMain() {
 
 namespace cs {
 
-CS_Sink CreateCvSink(const wpi::Twine& name, CS_Status* status) {
+CS_Sink CreateCvSink(std::string_view name, CS_Status* status) {
   auto& inst = Instance::GetInstance();
   return inst.CreateSink(
       CS_SINK_CV, std::make_shared<CvSinkImpl>(name, inst.logger, inst.notifier,
                                                inst.telemetry));
 }
 
-CS_Sink CreateCvSinkCallback(const wpi::Twine& name,
+CS_Sink CreateCvSinkCallback(std::string_view name,
                              std::function<void(uint64_t time)> processFrame,
                              CS_Status* status) {
   auto& inst = Instance::GetInstance();
@@ -145,7 +145,7 @@ CS_Sink CreateCvSinkCallback(const wpi::Twine& name,
 
 static constexpr unsigned SinkMask = CS_SINK_CV | CS_SINK_RAW;
 
-void SetSinkDescription(CS_Sink sink, const wpi::Twine& description,
+void SetSinkDescription(CS_Sink sink, std::string_view description,
                         CS_Status* status) {
   auto data = Instance::GetInstance().GetSink(sink);
   if (!data || (data->kind & SinkMask) == 0) {
@@ -183,12 +183,12 @@ std::string GetSinkError(CS_Sink sink, CS_Status* status) {
   return static_cast<CvSinkImpl&>(*data->sink).GetError();
 }
 
-wpi::StringRef GetSinkError(CS_Sink sink, wpi::SmallVectorImpl<char>& buf,
-                            CS_Status* status) {
+std::string_view GetSinkError(CS_Sink sink, wpi::SmallVectorImpl<char>& buf,
+                              CS_Status* status) {
   auto data = Instance::GetInstance().GetSink(sink);
   if (!data || (data->kind & SinkMask) == 0) {
     *status = CS_INVALID_HANDLE;
-    return wpi::StringRef{};
+    return {};
   }
   return static_cast<CvSinkImpl&>(*data->sink).GetError(buf);
 }
diff --git a/cscore/src/main/native/cpp/CvSinkImpl.h b/cscore/src/main/native/cpp/CvSinkImpl.h
index b07cf7c530..ad63a20f1a 100644
--- a/cscore/src/main/native/cpp/CvSinkImpl.h
+++ b/cscore/src/main/native/cpp/CvSinkImpl.h
@@ -9,10 +9,10 @@
 
 #include <atomic>
 #include <functional>
+#include <string_view>
 #include <thread>
 
 #include <opencv2/core/core.hpp>
-#include <wpi/Twine.h>
 #include <wpi/condition_variable.h>
 
 #include "Frame.h"
@@ -24,9 +24,9 @@ class SourceImpl;
 
 class CvSinkImpl : public SinkImpl {
  public:
-  CvSinkImpl(const wpi::Twine& name, wpi::Logger& logger, Notifier& notifier,
+  CvSinkImpl(std::string_view name, wpi::Logger& logger, Notifier& notifier,
              Telemetry& telemetry);
-  CvSinkImpl(const wpi::Twine& name, wpi::Logger& logger, Notifier& notifier,
+  CvSinkImpl(std::string_view name, wpi::Logger& logger, Notifier& notifier,
              Telemetry& telemetry,
              std::function<void(uint64_t time)> processFrame);
   ~CvSinkImpl() override;
diff --git a/cscore/src/main/native/cpp/CvSourceImpl.cpp b/cscore/src/main/native/cpp/CvSourceImpl.cpp
index fa95f4400c..d05d89af70 100644
--- a/cscore/src/main/native/cpp/CvSourceImpl.cpp
+++ b/cscore/src/main/native/cpp/CvSourceImpl.cpp
@@ -19,7 +19,7 @@
 
 using namespace cs;
 
-CvSourceImpl::CvSourceImpl(const wpi::Twine& name, wpi::Logger& logger,
+CvSourceImpl::CvSourceImpl(std::string_view name, wpi::Logger& logger,
                            Notifier& notifier, Telemetry& telemetry,
                            const VideoMode& mode)
     : ConfigurableSourceImpl{name, logger, notifier, telemetry, mode} {}
@@ -53,8 +53,7 @@ void CvSourceImpl::PutFrame(cv::Mat& image) {
       cv::cvtColor(finalImage, dest->AsMat(), cv::COLOR_BGRA2BGR);
       break;
     default:
-      SERROR("PutFrame: " << image.channels()
-                          << "-channel images not supported");
+      SERROR("PutFrame: {}-channel images not supported", image.channels());
       return;
   }
   SourceImpl::PutFrame(std::move(dest), wpi::Now());
@@ -62,7 +61,7 @@ void CvSourceImpl::PutFrame(cv::Mat& image) {
 
 namespace cs {
 
-CS_Source CreateCvSource(const wpi::Twine& name, const VideoMode& mode,
+CS_Source CreateCvSource(std::string_view name, const VideoMode& mode,
                          CS_Status* status) {
   auto& inst = Instance::GetInstance();
   return inst.CreateSource(CS_SOURCE_CV, std::make_shared<CvSourceImpl>(
@@ -81,7 +80,7 @@ void PutSourceFrame(CS_Source source, cv::Mat& image, CS_Status* status) {
 
 static constexpr unsigned SourceMask = CS_SINK_CV | CS_SINK_RAW;
 
-void NotifySourceError(CS_Source source, const wpi::Twine& msg,
+void NotifySourceError(CS_Source source, std::string_view msg,
                        CS_Status* status) {
   auto data = Instance::GetInstance().GetSource(source);
   if (!data || (data->kind & SourceMask) == 0) {
@@ -100,7 +99,7 @@ void SetSourceConnected(CS_Source source, bool connected, CS_Status* status) {
   static_cast<CvSourceImpl&>(*data->source).SetConnected(connected);
 }
 
-void SetSourceDescription(CS_Source source, const wpi::Twine& description,
+void SetSourceDescription(CS_Source source, std::string_view description,
                           CS_Status* status) {
   auto data = Instance::GetInstance().GetSource(source);
   if (!data || (data->kind & SourceMask) == 0) {
@@ -110,7 +109,7 @@ void SetSourceDescription(CS_Source source, const wpi::Twine& description,
   static_cast<CvSourceImpl&>(*data->source).SetDescription(description);
 }
 
-CS_Property CreateSourceProperty(CS_Source source, const wpi::Twine& name,
+CS_Property CreateSourceProperty(CS_Source source, std::string_view name,
                                  CS_PropertyKind kind, int minimum, int maximum,
                                  int step, int defaultValue, int value,
                                  CS_Status* status) {
@@ -126,7 +125,7 @@ CS_Property CreateSourceProperty(CS_Source source, const wpi::Twine& name,
 }
 
 CS_Property CreateSourcePropertyCallback(
-    CS_Source source, const wpi::Twine& name, CS_PropertyKind kind, int minimum,
+    CS_Source source, std::string_view name, CS_PropertyKind kind, int minimum,
     int maximum, int step, int defaultValue, int value,
     std::function<void(CS_Property property)> onChange, CS_Status* status) {
   auto data = Instance::GetInstance().GetSource(source);
diff --git a/cscore/src/main/native/cpp/CvSourceImpl.h b/cscore/src/main/native/cpp/CvSourceImpl.h
index dc9bcb3ca5..1956fbe56d 100644
--- a/cscore/src/main/native/cpp/CvSourceImpl.h
+++ b/cscore/src/main/native/cpp/CvSourceImpl.h
@@ -9,11 +9,11 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <opencv2/core/core.hpp>
 #include <wpi/ArrayRef.h>
-#include <wpi/Twine.h>
 
 #include "ConfigurableSourceImpl.h"
 #include "SourceImpl.h"
@@ -22,7 +22,7 @@ namespace cs {
 
 class CvSourceImpl : public ConfigurableSourceImpl {
  public:
-  CvSourceImpl(const wpi::Twine& name, wpi::Logger& logger, Notifier& notifier,
+  CvSourceImpl(std::string_view name, wpi::Logger& logger, Notifier& notifier,
                Telemetry& telemetry, const VideoMode& mode);
   ~CvSourceImpl() override;
 
diff --git a/cscore/src/main/native/cpp/Frame.cpp b/cscore/src/main/native/cpp/Frame.cpp
index 71bd446206..0aa1947f00 100644
--- a/cscore/src/main/native/cpp/Frame.cpp
+++ b/cscore/src/main/native/cpp/Frame.cpp
@@ -16,10 +16,10 @@
 
 using namespace cs;
 
-Frame::Frame(SourceImpl& source, const wpi::Twine& error, Time time)
+Frame::Frame(SourceImpl& source, std::string_view error, Time time)
     : m_impl{source.AllocFrameImpl().release()} {
   m_impl->refcount = 1;
-  m_impl->error = error.str();
+  m_impl->error = error;
   m_impl->time = time;
 }
 
@@ -522,10 +522,8 @@ Image* Frame::GetImageImpl(int width, int height,
   }
 
   WPI_DEBUG4(Instance::GetInstance().logger,
-             "converting image from " << cur->width << "x" << cur->height
-                                      << " type " << cur->pixelFormat << " to "
-                                      << width << "x" << height << " type "
-                                      << pixelFormat);
+             "converting image from {}x{} type {} to {}x{} type {}", cur->width,
+             cur->height, cur->pixelFormat, width, height, pixelFormat);
 
   // If the source image is a JPEG, we need to decode it before we can do
   // anything else with it.  Note that if the destination format is JPEG, we
diff --git a/cscore/src/main/native/cpp/Frame.h b/cscore/src/main/native/cpp/Frame.h
index 3177d2625c..9a16824021 100644
--- a/cscore/src/main/native/cpp/Frame.h
+++ b/cscore/src/main/native/cpp/Frame.h
@@ -8,11 +8,11 @@
 #include <atomic>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
 #include <wpi/SmallVector.h>
-#include <wpi/Twine.h>
 #include <wpi/mutex.h>
 
 #include "Image.h"
@@ -44,7 +44,7 @@ class Frame {
  public:
   Frame() noexcept = default;
 
-  Frame(SourceImpl& source, const wpi::Twine& error, Time time);
+  Frame(SourceImpl& source, std::string_view error, Time time);
 
   Frame(SourceImpl& source, std::unique_ptr<Image> image, Time time);
 
@@ -72,7 +72,7 @@ class Frame {
 
   Time GetTime() const { return m_impl ? m_impl->time : 0; }
 
-  wpi::StringRef GetError() const {
+  std::string_view GetError() const {
     if (!m_impl) {
       return {};
     }
diff --git a/cscore/src/main/native/cpp/HttpCameraImpl.cpp b/cscore/src/main/native/cpp/HttpCameraImpl.cpp
index 3d1c64883b..5cbe9436d6 100644
--- a/cscore/src/main/native/cpp/HttpCameraImpl.cpp
+++ b/cscore/src/main/native/cpp/HttpCameraImpl.cpp
@@ -5,6 +5,7 @@
 #include "HttpCameraImpl.h"
 
 #include <wpi/MemAlloc.h>
+#include <wpi/StringExtras.h>
 #include <wpi/TCPConnector.h>
 #include <wpi/timestamp.h>
 
@@ -18,7 +19,7 @@
 
 using namespace cs;
 
-HttpCameraImpl::HttpCameraImpl(const wpi::Twine& name, CS_HttpCameraKind kind,
+HttpCameraImpl::HttpCameraImpl(std::string_view name, CS_HttpCameraKind kind,
                                wpi::Logger& logger, Notifier& notifier,
                                Telemetry& telemetry)
     : SourceImpl{name, logger, notifier, telemetry}, m_kind{kind} {}
@@ -84,7 +85,7 @@ void HttpCameraImpl::MonitorThreadMain() {
     // (this will result in an error at the read point, and ultimately
     // a reconnect attempt)
     if (m_streamConn && m_frameCount == 0) {
-      SWARNING("Monitor detected stream hung, disconnecting");
+      SWARNING("{}", "Monitor detected stream hung, disconnecting");
       m_streamConn->stream->close();
     }
 
@@ -92,7 +93,7 @@ void HttpCameraImpl::MonitorThreadMain() {
     m_frameCount = 0;
   }
 
-  SDEBUG("Monitor Thread exiting");
+  SDEBUG("{}", "Monitor Thread exiting");
 }
 
 void HttpCameraImpl::StreamThreadMain() {
@@ -132,14 +133,14 @@ void HttpCameraImpl::StreamThreadMain() {
     SetConnected(true);
 
     // stream
-    DeviceStream(conn->is, boundary);
+    DeviceStream(conn->is, boundary.str());
     {
       std::unique_lock lock(m_mutex);
       m_streamConn = nullptr;
     }
   }
 
-  SDEBUG("Camera Thread exiting");
+  SDEBUG("{}", "Camera Thread exiting");
   SetConnected(false);
 }
 
@@ -150,7 +151,7 @@ wpi::HttpConnection* HttpCameraImpl::DeviceStreamConnect(
   {
     std::scoped_lock lock(m_mutex);
     if (m_locations.empty()) {
-      SERROR("locations array is empty!?");
+      SERROR("{}", "locations array is empty!?");
       std::this_thread::sleep_for(std::chrono::seconds(1));
       return nullptr;
     }
@@ -181,19 +182,17 @@ wpi::HttpConnection* HttpCameraImpl::DeviceStreamConnect(
 
   std::string warn;
   if (!conn->Handshake(req, &warn)) {
-    SWARNING(GetName() << ": " << warn);
+    SWARNING("{}", warn);
     std::scoped_lock lock(m_mutex);
     m_streamConn = nullptr;
     return nullptr;
   }
 
   // Parse Content-Type header to get the boundary
-  wpi::StringRef mediaType, contentType;
-  std::tie(mediaType, contentType) = conn->contentType.str().split(';');
-  mediaType = mediaType.trim();
+  auto [mediaType, contentType] = wpi::split(conn->contentType.str(), ';');
+  mediaType = wpi::trim(mediaType);
   if (mediaType != "multipart/x-mixed-replace") {
-    SWARNING("\"" << req.host << "\": unrecognized Content-Type \"" << mediaType
-                  << "\"");
+    SWARNING("\"{}\": unrecognized Content-Type \"{}\"", req.host, mediaType);
     std::scoped_lock lock(m_mutex);
     m_streamConn = nullptr;
     return nullptr;
@@ -202,14 +201,13 @@ wpi::HttpConnection* HttpCameraImpl::DeviceStreamConnect(
   // media parameters
   boundary.clear();
   while (!contentType.empty()) {
-    wpi::StringRef keyvalue;
-    std::tie(keyvalue, contentType) = contentType.split(';');
-    contentType = contentType.ltrim();
-    wpi::StringRef key, value;
-    std::tie(key, value) = keyvalue.split('=');
-    if (key.trim() == "boundary") {
-      value = value.trim().trim('"');  // value may be quoted
-      if (value.startswith("--")) {
+    std::string_view keyvalue;
+    std::tie(keyvalue, contentType) = wpi::split(contentType, ';');
+    contentType = wpi::ltrim(contentType);
+    auto [key, value] = wpi::split(keyvalue, '=');
+    if (wpi::trim(key) == "boundary") {
+      value = wpi::trim(wpi::trim(value), '"');  // value may be quoted
+      if (wpi::starts_with(value, "--")) {
         value = value.substr(2);
       }
       boundary.append(value.begin(), value.end());
@@ -217,8 +215,7 @@ wpi::HttpConnection* HttpCameraImpl::DeviceStreamConnect(
   }
 
   if (boundary.empty()) {
-    SWARNING("\"" << req.host
-                  << "\": empty multi-part boundary or no Content-Type");
+    SWARNING("\"{}\": empty multi-part boundary or no Content-Type", req.host);
     std::scoped_lock lock(m_mutex);
     m_streamConn = nullptr;
     return nullptr;
@@ -228,7 +225,7 @@ wpi::HttpConnection* HttpCameraImpl::DeviceStreamConnect(
 }
 
 void HttpCameraImpl::DeviceStream(wpi::raw_istream& is,
-                                  wpi::StringRef boundary) {
+                                  std::string_view boundary) {
   // Stored here so we reuse it from frame to frame
   std::string imageBuf;
 
@@ -275,28 +272,29 @@ bool HttpCameraImpl::DeviceStreamFrame(wpi::raw_istream& is,
   wpi::SmallString<64> contentTypeBuf;
   wpi::SmallString<64> contentLengthBuf;
   if (!ParseHttpHeaders(is, &contentTypeBuf, &contentLengthBuf)) {
-    SWARNING("disconnected during headers");
+    SWARNING("{}", "disconnected during headers");
     PutError("disconnected during headers", wpi::Now());
     return false;
   }
 
   // Check the content type (if present)
   if (!contentTypeBuf.str().empty() &&
-      !contentTypeBuf.str().startswith("image/jpeg")) {
-    wpi::SmallString<64> errBuf;
-    wpi::raw_svector_ostream errMsg{errBuf};
-    errMsg << "received unknown Content-Type \"" << contentTypeBuf << "\"";
-    SWARNING(errMsg.str());
-    PutError(errMsg.str(), wpi::Now());
+      !wpi::starts_with(contentTypeBuf, "image/jpeg")) {
+    auto errMsg =
+        fmt::format("received unknown Content-Type \"{}\"", contentTypeBuf);
+    SWARNING("{}", errMsg);
+    PutError(errMsg, wpi::Now());
     return false;
   }
 
   unsigned int contentLength = 0;
-  if (contentLengthBuf.str().getAsInteger(10, contentLength)) {
+  if (auto v = wpi::parse_integer<unsigned int>(contentLengthBuf, 10)) {
+    contentLength = v.value();
+  } else {
     // Ugh, no Content-Length?  Read the blocks of the JPEG file.
     int width, height;
     if (!ReadJpeg(is, imageBuf, &width, &height)) {
-      SWARNING("did not receive a JPEG image");
+      SWARNING("{}", "did not receive a JPEG image");
       PutError("did not receive a JPEG image", wpi::Now());
       return false;
     }
@@ -315,7 +313,7 @@ bool HttpCameraImpl::DeviceStreamFrame(wpi::raw_istream& is,
   }
   int width, height;
   if (!GetJpegSize(image->str(), &width, &height)) {
-    SWARNING("did not receive a JPEG image");
+    SWARNING("{}", "did not receive a JPEG image");
     PutError("did not receive a JPEG image", wpi::Now());
     return false;
   }
@@ -345,7 +343,7 @@ void HttpCameraImpl::SettingsThreadMain() {
     DeviceSendSettings(req);
   }
 
-  SDEBUG("Settings Thread exiting");
+  SDEBUG("{}", "Settings Thread exiting");
 }
 
 void HttpCameraImpl::DeviceSendSettings(wpi::HttpRequest& req) {
@@ -369,7 +367,7 @@ void HttpCameraImpl::DeviceSendSettings(wpi::HttpRequest& req) {
   // Just need a handshake as settings are sent via GET parameters
   std::string warn;
   if (!conn->Handshake(req, &warn)) {
-    SWARNING(GetName() << ": " << warn);
+    SWARNING("{}", warn);
   }
 
   conn->stream->close();
@@ -388,7 +386,7 @@ bool HttpCameraImpl::SetUrls(wpi::ArrayRef<std::string> urls,
     std::string errorMsg;
     locations.emplace_back(url, &error, &errorMsg);
     if (error) {
-      SERROR(GetName() << ": " << errorMsg);
+      SERROR("{}", errorMsg);
       *status = CS_BAD_URL;
       return false;
     }
@@ -410,8 +408,8 @@ std::vector<std::string> HttpCameraImpl::GetUrls() const {
   return urls;
 }
 
-void HttpCameraImpl::CreateProperty(const wpi::Twine& name,
-                                    const wpi::Twine& httpParam,
+void HttpCameraImpl::CreateProperty(std::string_view name,
+                                    std::string_view httpParam,
                                     bool viaSettings, CS_PropertyKind kind,
                                     int minimum, int maximum, int step,
                                     int defaultValue, int value) const {
@@ -421,13 +419,12 @@ void HttpCameraImpl::CreateProperty(const wpi::Twine& name,
       value));
 
   m_notifier.NotifySourceProperty(*this, CS_SOURCE_PROPERTY_CREATED, name,
-                                  m_propertyData.size() + 1, kind, value,
-                                  wpi::Twine{});
+                                  m_propertyData.size() + 1, kind, value, {});
 }
 
 template <typename T>
 void HttpCameraImpl::CreateEnumProperty(
-    const wpi::Twine& name, const wpi::Twine& httpParam, bool viaSettings,
+    std::string_view name, std::string_view httpParam, bool viaSettings,
     int defaultValue, int value, std::initializer_list<T> choices) const {
   std::scoped_lock lock(m_mutex);
   m_propertyData.emplace_back(std::make_unique<PropertyData>(
@@ -442,14 +439,14 @@ void HttpCameraImpl::CreateEnumProperty(
 
   m_notifier.NotifySourceProperty(*this, CS_SOURCE_PROPERTY_CREATED, name,
                                   m_propertyData.size() + 1, CS_PROP_ENUM,
-                                  value, wpi::Twine{});
+                                  value, {});
   m_notifier.NotifySourceProperty(*this, CS_SOURCE_PROPERTY_CHOICES_UPDATED,
                                   name, m_propertyData.size() + 1, CS_PROP_ENUM,
-                                  value, wpi::Twine{});
+                                  value, {});
 }
 
 std::unique_ptr<PropertyImpl> HttpCameraImpl::CreateEmptyProperty(
-    const wpi::Twine& name) const {
+    std::string_view name) const {
   return std::make_unique<PropertyData>(name);
 }
 
@@ -474,7 +471,7 @@ void HttpCameraImpl::SetProperty(int property, int value, CS_Status* status) {
   // TODO
 }
 
-void HttpCameraImpl::SetStringProperty(int property, const wpi::Twine& value,
+void HttpCameraImpl::SetStringProperty(int property, std::string_view value,
                                        CS_Status* status) {
   // TODO
 }
@@ -560,7 +557,7 @@ bool AxisCameraImpl::CacheProperties(CS_Status* status) const {
 
 namespace cs {
 
-CS_Source CreateHttpCamera(const wpi::Twine& name, const wpi::Twine& url,
+CS_Source CreateHttpCamera(std::string_view name, std::string_view url,
                            CS_HttpCameraKind kind, CS_Status* status) {
   auto& inst = Instance::GetInstance();
   std::shared_ptr<HttpCameraImpl> source;
@@ -574,13 +571,13 @@ CS_Source CreateHttpCamera(const wpi::Twine& name, const wpi::Twine& url,
                                                 inst.notifier, inst.telemetry);
       break;
   }
-  if (!source->SetUrls(url.str(), status)) {
+  if (!source->SetUrls(std::string{url}, status)) {
     return 0;
   }
   return inst.CreateSource(CS_SOURCE_HTTP, source);
 }
 
-CS_Source CreateHttpCamera(const wpi::Twine& name,
+CS_Source CreateHttpCamera(std::string_view name,
                            wpi::ArrayRef<std::string> urls,
                            CS_HttpCameraKind kind, CS_Status* status) {
   auto& inst = Instance::GetInstance();
diff --git a/cscore/src/main/native/cpp/HttpCameraImpl.h b/cscore/src/main/native/cpp/HttpCameraImpl.h
index 459d8fc1a6..1d375a82df 100644
--- a/cscore/src/main/native/cpp/HttpCameraImpl.h
+++ b/cscore/src/main/native/cpp/HttpCameraImpl.h
@@ -10,13 +10,13 @@
 #include <initializer_list>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <thread>
 #include <vector>
 
 #include <wpi/HttpUtil.h>
 #include <wpi/SmallString.h>
 #include <wpi/StringMap.h>
-#include <wpi/Twine.h>
 #include <wpi/condition_variable.h>
 #include <wpi/raw_istream.h>
 
@@ -27,7 +27,7 @@ namespace cs {
 
 class HttpCameraImpl : public SourceImpl {
  public:
-  HttpCameraImpl(const wpi::Twine& name, CS_HttpCameraKind kind,
+  HttpCameraImpl(std::string_view name, CS_HttpCameraKind kind,
                  wpi::Logger& logger, Notifier& notifier, Telemetry& telemetry);
   ~HttpCameraImpl() override;
 
@@ -35,7 +35,7 @@ class HttpCameraImpl : public SourceImpl {
 
   // Property functions
   void SetProperty(int property, int value, CS_Status* status) override;
-  void SetStringProperty(int property, const wpi::Twine& value,
+  void SetStringProperty(int property, std::string_view value,
                          CS_Status* status) override;
 
   // Standard common camera properties
@@ -61,13 +61,13 @@ class HttpCameraImpl : public SourceImpl {
   class PropertyData : public PropertyImpl {
    public:
     PropertyData() = default;
-    explicit PropertyData(const wpi::Twine& name_) : PropertyImpl{name_} {}
-    PropertyData(const wpi::Twine& name_, const wpi::Twine& httpParam_,
+    explicit PropertyData(std::string_view name_) : PropertyImpl{name_} {}
+    PropertyData(std::string_view name_, std::string_view httpParam_,
                  bool viaSettings_, CS_PropertyKind kind_, int minimum_,
                  int maximum_, int step_, int defaultValue_, int value_)
         : PropertyImpl(name_, kind_, step_, defaultValue_, value_),
           viaSettings(viaSettings_),
-          httpParam(httpParam_.str()) {
+          httpParam(httpParam_) {
       hasMinimum = true;
       minimum = minimum_;
       hasMaximum = true;
@@ -81,16 +81,16 @@ class HttpCameraImpl : public SourceImpl {
 
  protected:
   std::unique_ptr<PropertyImpl> CreateEmptyProperty(
-      const wpi::Twine& name) const override;
+      std::string_view name) const override;
 
   bool CacheProperties(CS_Status* status) const override;
 
-  void CreateProperty(const wpi::Twine& name, const wpi::Twine& httpParam,
+  void CreateProperty(std::string_view name, std::string_view httpParam,
                       bool viaSettings, CS_PropertyKind kind, int minimum,
                       int maximum, int step, int defaultValue, int value) const;
 
   template <typename T>
-  void CreateEnumProperty(const wpi::Twine& name, const wpi::Twine& httpParam,
+  void CreateEnumProperty(std::string_view name, std::string_view httpParam,
                           bool viaSettings, int defaultValue, int value,
                           std::initializer_list<T> choices) const;
 
@@ -101,7 +101,7 @@ class HttpCameraImpl : public SourceImpl {
   // Functions used by StreamThreadMain()
   wpi::HttpConnection* DeviceStreamConnect(
       wpi::SmallVectorImpl<char>& boundary);
-  void DeviceStream(wpi::raw_istream& is, wpi::StringRef boundary);
+  void DeviceStream(wpi::raw_istream& is, std::string_view boundary);
   bool DeviceStreamFrame(wpi::raw_istream& is, std::string& imageBuf);
 
   // The camera settings thread
@@ -146,12 +146,12 @@ class HttpCameraImpl : public SourceImpl {
 
 class AxisCameraImpl : public HttpCameraImpl {
  public:
-  AxisCameraImpl(const wpi::Twine& name, wpi::Logger& logger,
-                 Notifier& notifier, Telemetry& telemetry)
+  AxisCameraImpl(std::string_view name, wpi::Logger& logger, Notifier& notifier,
+                 Telemetry& telemetry)
       : HttpCameraImpl{name, CS_HTTP_AXIS, logger, notifier, telemetry} {}
 #if 0
   void SetProperty(int property, int value, CS_Status* status) override;
-  void SetStringProperty(int property, const wpi::Twine& value,
+  void SetStringProperty(int property, std::string_view value,
                          CS_Status* status) override;
 #endif
  protected:
diff --git a/cscore/src/main/native/cpp/Image.h b/cscore/src/main/native/cpp/Image.h
index 110bee4994..9a1579f281 100644
--- a/cscore/src/main/native/cpp/Image.h
+++ b/cscore/src/main/native/cpp/Image.h
@@ -5,10 +5,10 @@
 #ifndef CSCORE_IMAGE_H_
 #define CSCORE_IMAGE_H_
 
+#include <string_view>
 #include <vector>
 
 #include <opencv2/core/core.hpp>
-#include <wpi/StringRef.h>
 
 #include "cscore_cpp.h"
 #include "default_init_allocator.h"
@@ -34,8 +34,8 @@ class Image {
   Image& operator=(const Image&) = delete;
 
   // Getters
-  operator wpi::StringRef() const { return str(); }  // NOLINT
-  wpi::StringRef str() const { return wpi::StringRef(data(), size()); }
+  operator std::string_view() const { return str(); }  // NOLINT
+  std::string_view str() const { return {data(), size()}; }
   size_t capacity() const { return m_data.capacity(); }
   const char* data() const {
     return reinterpret_cast<const char*>(m_data.data());
diff --git a/cscore/src/main/native/cpp/Instance.cpp b/cscore/src/main/native/cpp/Instance.cpp
index a42f7d48f2..3b81f01658 100644
--- a/cscore/src/main/native/cpp/Instance.cpp
+++ b/cscore/src/main/native/cpp/Instance.cpp
@@ -4,36 +4,32 @@
 
 #include "Instance.h"
 
-#include <wpi/SmallString.h>
-#include <wpi/StringRef.h>
+#include <string_view>
+
+#include <fmt/format.h>
 #include <wpi/fs.h>
-#include <wpi/raw_ostream.h>
 
 using namespace cs;
 
 static void def_log_func(unsigned int level, const char* file,
                          unsigned int line, const char* msg) {
-  wpi::SmallString<128> buf;
-  wpi::raw_svector_ostream oss(buf);
   if (level == 20) {
-    oss << "CS: " << msg << '\n';
-    wpi::errs() << oss.str();
+    fmt::print(stderr, "CS: {}\n", msg);
     return;
   }
 
-  wpi::StringRef levelmsg;
+  std::string_view levelmsg;
   if (level >= 50) {
-    levelmsg = "CRITICAL: ";
+    levelmsg = "CRITICAL";
   } else if (level >= 40) {
-    levelmsg = "ERROR: ";
+    levelmsg = "ERROR";
   } else if (level >= 30) {
-    levelmsg = "WARNING: ";
+    levelmsg = "WARNING";
   } else {
     return;
   }
-  oss << "CS: " << levelmsg << msg << " (" << fs::path{file}.filename().string()
-      << ':' << line << ")\n";
-  wpi::errs() << oss.str();
+  fmt::print(stderr, "CS: {}: {} ({}:{})\n", levelmsg, msg,
+             fs::path{file}.filename().string(), line);
 }
 
 Instance::Instance()
diff --git a/cscore/src/main/native/cpp/JpegUtil.cpp b/cscore/src/main/native/cpp/JpegUtil.cpp
index 0ec9eee375..2e66338974 100644
--- a/cscore/src/main/native/cpp/JpegUtil.cpp
+++ b/cscore/src/main/native/cpp/JpegUtil.cpp
@@ -46,20 +46,20 @@ static const unsigned char dhtData[] = {
     0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
     0xe8, 0xe9, 0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa};
 
-bool IsJpeg(wpi::StringRef data) {
+bool IsJpeg(std::string_view data) {
   if (data.size() < 11) {
     return false;
   }
 
   // Check for valid SOI
-  auto bytes = data.bytes_begin();
+  auto bytes = reinterpret_cast<const unsigned char*>(data.data());
   if (bytes[0] != 0xff || bytes[1] != 0xd8) {
     return false;
   }
   return true;
 }
 
-bool GetJpegSize(wpi::StringRef data, int* width, int* height) {
+bool GetJpegSize(std::string_view data, int* width, int* height) {
   if (!IsJpeg(data)) {
     return false;
   }
@@ -69,7 +69,7 @@ bool GetJpegSize(wpi::StringRef data, int* width, int* height) {
     if (data.size() < 4) {
       return false;  // EOF
     }
-    auto bytes = data.bytes_begin();
+    auto bytes = reinterpret_cast<const unsigned char*>(data.data());
     if (bytes[0] != 0xff) {
       return false;  // not a tag
     }
@@ -94,7 +94,7 @@ bool GetJpegSize(wpi::StringRef data, int* width, int* height) {
 }
 
 bool JpegNeedsDHT(const char* data, size_t* size, size_t* locSOF) {
-  wpi::StringRef sdata(data, *size);
+  std::string_view sdata(data, *size);
   if (!IsJpeg(sdata)) {
     return false;
   }
@@ -107,7 +107,7 @@ bool JpegNeedsDHT(const char* data, size_t* size, size_t* locSOF) {
     if (sdata.size() < 4) {
       return false;  // EOF
     }
-    auto bytes = sdata.bytes_begin();
+    auto bytes = reinterpret_cast<const unsigned char*>(sdata.data());
     if (bytes[0] != 0xff) {
       return false;  // not a tag
     }
@@ -132,9 +132,8 @@ bool JpegNeedsDHT(const char* data, size_t* size, size_t* locSOF) {
   return false;
 }
 
-wpi::StringRef JpegGetDHT() {
-  return wpi::StringRef(reinterpret_cast<const char*>(dhtData),
-                        sizeof(dhtData));
+std::string_view JpegGetDHT() {
+  return {reinterpret_cast<const char*>(dhtData), sizeof(dhtData)};
 }
 
 static inline void ReadInto(wpi::raw_istream& is, std::string& buf,
diff --git a/cscore/src/main/native/cpp/JpegUtil.h b/cscore/src/main/native/cpp/JpegUtil.h
index 5d68f19659..4fe0693f59 100644
--- a/cscore/src/main/native/cpp/JpegUtil.h
+++ b/cscore/src/main/native/cpp/JpegUtil.h
@@ -6,8 +6,7 @@
 #define CSCORE_JPEGUTIL_H_
 
 #include <string>
-
-#include <wpi/StringRef.h>
+#include <string_view>
 
 namespace wpi {
 class raw_istream;
@@ -15,13 +14,13 @@ class raw_istream;
 
 namespace cs {
 
-bool IsJpeg(wpi::StringRef data);
+bool IsJpeg(std::string_view data);
 
-bool GetJpegSize(wpi::StringRef data, int* width, int* height);
+bool GetJpegSize(std::string_view data, int* width, int* height);
 
 bool JpegNeedsDHT(const char* data, size_t* size, size_t* locSOF);
 
-wpi::StringRef JpegGetDHT();
+std::string_view JpegGetDHT();
 
 bool ReadJpeg(wpi::raw_istream& is, std::string& buf, int* width, int* height);
 
diff --git a/cscore/src/main/native/cpp/Log.cpp b/cscore/src/main/native/cpp/Log.cpp
new file mode 100644
index 0000000000..baf2e5eb98
--- /dev/null
+++ b/cscore/src/main/native/cpp/Log.cpp
@@ -0,0 +1,15 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include "Log.h"
+
+void cs::NamedLogV(wpi::Logger& logger, unsigned int level, const char* file,
+                   unsigned int line, std::string_view name,
+                   fmt::string_view format, fmt::format_args args) {
+  fmt::memory_buffer out;
+  fmt::format_to(out, "{}: ", name);
+  fmt::vformat_to(out, format, args);
+  out.push_back('\0');
+  logger.DoLog(level, file, line, out.data());
+}
diff --git a/cscore/src/main/native/cpp/Log.h b/cscore/src/main/native/cpp/Log.h
index c56389c75e..21becdf357 100644
--- a/cscore/src/main/native/cpp/Log.h
+++ b/cscore/src/main/native/cpp/Log.h
@@ -5,29 +5,71 @@
 #ifndef CSCORE_LOG_H_
 #define CSCORE_LOG_H_
 
+#include <string_view>
+
 #include <wpi/Logger.h>
 
-#define LOG(level, x) WPI_LOG(m_logger, level, x)
+namespace cs {
+
+void NamedLogV(wpi::Logger& logger, unsigned int level, const char* file,
+               unsigned int line, std::string_view name,
+               fmt::string_view format, fmt::format_args args);
+
+template <typename S, typename... Args>
+inline void NamedLog(wpi::Logger& logger, unsigned int level, const char* file,
+                     unsigned int line, std::string_view name, const S& format,
+                     Args&&... args) {
+  if (logger.HasLogger() && level >= logger.min_level()) {
+    NamedLogV(logger, level, file, line, name, format,
+              fmt::make_args_checked<Args...>(format, args...));
+  }
+}
+
+}  // namespace cs
+
+#define LOG(level, format, ...) WPI_LOG(m_logger, level, format, __VA_ARGS__)
 
 #undef ERROR
-#define ERROR(x) WPI_ERROR(m_logger, x)
-#define WARNING(x) WPI_WARNING(m_logger, x)
-#define INFO(x) WPI_INFO(m_logger, x)
+#define ERROR(format, ...) WPI_ERROR(m_logger, format, __VA_ARGS__)
+#define WARNING(format, ...) WPI_WARNING(m_logger, format, __VA_ARGS__)
+#define INFO(format, ...) WPI_INFO(m_logger, format, __VA_ARGS__)
 
-#define DEBUG0(x) WPI_DEBUG(m_logger, x)
-#define DEBUG1(x) WPI_DEBUG1(m_logger, x)
-#define DEBUG2(x) WPI_DEBUG2(m_logger, x)
-#define DEBUG3(x) WPI_DEBUG3(m_logger, x)
-#define DEBUG4(x) WPI_DEBUG4(m_logger, x)
+#define DEBUG0(format, ...) WPI_DEBUG(m_logger, format, __VA_ARGS__)
+#define DEBUG1(format, ...) WPI_DEBUG1(m_logger, format, __VA_ARGS__)
+#define DEBUG2(format, ...) WPI_DEBUG2(m_logger, format, __VA_ARGS__)
+#define DEBUG3(format, ...) WPI_DEBUG3(m_logger, format, __VA_ARGS__)
+#define DEBUG4(format, ...) WPI_DEBUG4(m_logger, format, __VA_ARGS__)
 
-#define SERROR(x) ERROR(GetName() << ": " << x)
-#define SWARNING(x) WARNING(GetName() << ": " << x)
-#define SINFO(x) INFO(GetName() << ": " << x)
+#define SLOG(level, format, ...)                                               \
+  NamedLog(m_logger, level, __FILE__, __LINE__, GetName(), FMT_STRING(format), \
+           __VA_ARGS__)
 
-#define SDEBUG(x) DEBUG0(GetName() << ": " << x)
-#define SDEBUG1(x) DEBUG1(GetName() << ": " << x)
-#define SDEBUG2(x) DEBUG2(GetName() << ": " << x)
-#define SDEBUG3(x) DEBUG3(GetName() << ": " << x)
-#define SDEBUG4(x) DEBUG4(GetName() << ": " << x)
+#define SERROR(format, ...) SLOG(::wpi::WPI_LOG_ERROR, format, __VA_ARGS__)
+#define SWARNING(format, ...) SLOG(::wpi::WPI_LOG_WARNING, format, __VA_ARGS__)
+#define SINFO(format, ...) SLOG(::wpi::WPI_LOG_INFO, format, __VA_ARGS__)
+
+#ifdef NDEBUG
+#define SDEBUG(format, ...) \
+  do {                      \
+  } while (0)
+#define SDEBUG1(format, ...) \
+  do {                       \
+  } while (0)
+#define SDEBUG2(format, ...) \
+  do {                       \
+  } while (0)
+#define SDEBUG3(format, ...) \
+  do {                       \
+  } while (0)
+#define SDEBUG4(format, ...) \
+  do {                       \
+  } while (0)
+#else
+#define SDEBUG(format, ...) SLOG(::wpi::WPI_LOG_DEBUG, format, __VA_ARGS__)
+#define SDEBUG1(format, ...) SLOG(::wpi::WPI_LOG_DEBUG1, format, __VA_ARGS__)
+#define SDEBUG2(format, ...) SLOG(::wpi::WPI_LOG_DEBUG2, format, __VA_ARGS__)
+#define SDEBUG3(format, ...) SLOG(::wpi::WPI_LOG_DEBUG3, format, __VA_ARGS__)
+#define SDEBUG4(format, ...) SLOG(::wpi::WPI_LOG_DEBUG4, format, __VA_ARGS__)
+#endif
 
 #endif  // CSCORE_LOG_H_
diff --git a/cscore/src/main/native/cpp/MjpegServerImpl.cpp b/cscore/src/main/native/cpp/MjpegServerImpl.cpp
index 4ffded64bc..92c23fff5e 100644
--- a/cscore/src/main/native/cpp/MjpegServerImpl.cpp
+++ b/cscore/src/main/native/cpp/MjpegServerImpl.cpp
@@ -6,9 +6,12 @@
 
 #include <chrono>
 
+#include <fmt/format.h>
 #include <wpi/HttpUtil.h>
 #include <wpi/SmallString.h>
+#include <wpi/StringExtras.h>
 #include <wpi/TCPAcceptor.h>
+#include <wpi/fmt/raw_ostream.h>
 #include <wpi/raw_socket_istream.h>
 #include <wpi/raw_socket_ostream.h>
 
@@ -72,13 +75,13 @@ static const char* endRootPage = "</div></body></html>";
 
 class MjpegServerImpl::ConnThread : public wpi::SafeThread {
  public:
-  explicit ConnThread(const wpi::Twine& name, wpi::Logger& logger)
-      : m_name(name.str()), m_logger(logger) {}
+  explicit ConnThread(std::string_view name, wpi::Logger& logger)
+      : m_name(name), m_logger(logger) {}
 
   void Main() override;
 
   bool ProcessCommand(wpi::raw_ostream& os, SourceImpl& source,
-                      wpi::StringRef parameters, bool respond);
+                      std::string_view parameters, bool respond);
   void SendJSON(wpi::raw_ostream& os, SourceImpl& source, bool header);
   void SendHTMLHeadTitle(wpi::raw_ostream& os) const;
   void SendHTML(wpi::raw_ostream& os, SourceImpl& source, bool header);
@@ -99,7 +102,7 @@ class MjpegServerImpl::ConnThread : public wpi::SafeThread {
   std::string m_name;
   wpi::Logger& m_logger;
 
-  wpi::StringRef GetName() { return m_name; }
+  std::string_view GetName() { return m_name; }
 
   std::shared_ptr<SourceImpl> GetSource() {
     std::scoped_lock lock(m_mutex);
@@ -130,10 +133,9 @@ class MjpegServerImpl::ConnThread : public wpi::SafeThread {
 // Using cached pictures would lead to showing old/outdated pictures.
 // Many browsers seem to ignore, or at least not always obey, those headers.
 static void SendHeader(wpi::raw_ostream& os, int code,
-                       const wpi::Twine& codeText,
-                       const wpi::Twine& contentType,
-                       const wpi::Twine& extra = wpi::Twine{}) {
-  os << "HTTP/1.0 " << code << ' ' << codeText << "\r\n";
+                       std::string_view codeText, std::string_view contentType,
+                       std::string_view extra = {}) {
+  fmt::print(os, "HTTP/1.0 {} {}\r\n", code, codeText);
   os << "Connection: close\r\n"
         "Server: CameraServer/1.0\r\n"
         "Cache-Control: no-store, no-cache, must-revalidate, pre-check=0, "
@@ -142,10 +144,8 @@ static void SendHeader(wpi::raw_ostream& os, int code,
         "Expires: Mon, 3 Jan 2000 12:34:56 GMT\r\n";
   os << "Content-Type: " << contentType << "\r\n";
   os << "Access-Control-Allow-Origin: *\r\nAccess-Control-Allow-Methods: *\r\n";
-  wpi::SmallString<128> extraBuf;
-  wpi::StringRef extraStr = extra.toStringRef(extraBuf);
-  if (!extraStr.empty()) {
-    os << extraStr << "\r\n";
+  if (!extra.empty()) {
+    os << extra << "\r\n";
   }
   os << "\r\n";  // header ends with a blank line
 }
@@ -154,8 +154,8 @@ static void SendHeader(wpi::raw_ostream& os, int code,
 // @param code HTTP error code (e.g. 404)
 // @param message Additional message text
 static void SendError(wpi::raw_ostream& os, int code,
-                      const wpi::Twine& message) {
-  wpi::StringRef codeText, extra, baseMessage;
+                      std::string_view message) {
+  std::string_view codeText, extra, baseMessage;
   switch (code) {
     case 401:
       codeText = "Unauthorized";
@@ -195,66 +195,61 @@ static void SendError(wpi::raw_ostream& os, int code,
 // Perform a command specified by HTTP GET parameters.
 bool MjpegServerImpl::ConnThread::ProcessCommand(wpi::raw_ostream& os,
                                                  SourceImpl& source,
-                                                 wpi::StringRef parameters,
+                                                 std::string_view parameters,
                                                  bool respond) {
   wpi::SmallString<256> responseBuf;
   wpi::raw_svector_ostream response{responseBuf};
   // command format: param1=value1&param2=value2...
   while (!parameters.empty()) {
     // split out next param and value
-    wpi::StringRef rawParam, rawValue;
-    std::tie(rawParam, parameters) = parameters.split('&');
+    std::string_view rawParam, rawValue;
+    std::tie(rawParam, parameters) = wpi::split(parameters, '&');
     if (rawParam.empty()) {
       continue;  // ignore "&&"
     }
-    std::tie(rawParam, rawValue) = rawParam.split('=');
+    std::tie(rawParam, rawValue) = wpi::split(rawParam, '=');
     if (rawParam.empty() || rawValue.empty()) {
       continue;  // ignore "param="
     }
-    SDEBUG4("HTTP parameter \"" << rawParam << "\" value \"" << rawValue
-                                << "\"");
+    SDEBUG4("HTTP parameter \"{}\" value \"{}\"", rawParam, rawValue);
 
     // unescape param
     bool error = false;
     wpi::SmallString<64> paramBuf;
-    wpi::StringRef param = wpi::UnescapeURI(rawParam, paramBuf, &error);
+    std::string_view param = wpi::UnescapeURI(rawParam, paramBuf, &error);
     if (error) {
-      wpi::SmallString<128> error;
-      wpi::raw_svector_ostream oss{error};
-      oss << "could not unescape parameter \"" << rawParam << "\"";
-      SendError(os, 500, error.str());
-      SDEBUG(error.str());
+      auto estr = fmt::format("could not unescape parameter \"{}\"", rawParam);
+      SendError(os, 500, estr);
+      SDEBUG("{}", estr);
       return false;
     }
 
     // unescape value
     wpi::SmallString<64> valueBuf;
-    wpi::StringRef value = wpi::UnescapeURI(rawValue, valueBuf, &error);
+    std::string_view value = wpi::UnescapeURI(rawValue, valueBuf, &error);
     if (error) {
-      wpi::SmallString<128> error;
-      wpi::raw_svector_ostream oss{error};
-      oss << "could not unescape value \"" << rawValue << "\"";
-      SendError(os, 500, error.str());
-      SDEBUG(error.str());
+      auto estr = fmt::format("could not unescape value \"{}\"", rawValue);
+      SendError(os, 500, estr);
+      SDEBUG("{}", estr);
       return false;
     }
 
     // Handle resolution, compression, and FPS.  These are handled locally
     // rather than passed to the source.
     if (param == "resolution") {
-      wpi::StringRef widthStr, heightStr;
-      std::tie(widthStr, heightStr) = value.split('x');
-      int width, height;
-      if (widthStr.getAsInteger(10, width)) {
+      auto [widthStr, heightStr] = wpi::split(value, 'x');
+      int width = wpi::parse_integer<int>(widthStr, 10).value_or(-1);
+      int height = wpi::parse_integer<int>(heightStr, 10).value_or(-1);
+      if (width < 0) {
         response << param << ": \"width is not an integer\"\r\n";
-        SWARNING("HTTP parameter \"" << param << "\" width \"" << widthStr
-                                     << "\" is not an integer");
+        SWARNING("HTTP parameter \"{}\" width \"{}\" is not an integer", param,
+                 widthStr);
         continue;
       }
-      if (heightStr.getAsInteger(10, height)) {
+      if (height < 0) {
         response << param << ": \"height is not an integer\"\r\n";
-        SWARNING("HTTP parameter \"" << param << "\" height \"" << heightStr
-                                     << "\" is not an integer");
+        SWARNING("HTTP parameter \"{}\" height \"{}\" is not an integer", param,
+                 heightStr);
         continue;
       }
       m_width = width;
@@ -264,29 +259,25 @@ bool MjpegServerImpl::ConnThread::ProcessCommand(wpi::raw_ostream& os,
     }
 
     if (param == "fps") {
-      int fps;
-      if (value.getAsInteger(10, fps)) {
-        response << param << ": \"invalid integer\"\r\n";
-        SWARNING("HTTP parameter \"" << param << "\" value \"" << value
-                                     << "\" is not an integer");
-        continue;
-      } else {
-        m_fps = fps;
+      if (auto v = wpi::parse_integer<int>(value, 10)) {
+        m_fps = v.value();
         response << param << ": \"ok\"\r\n";
+      } else {
+        response << param << ": \"invalid integer\"\r\n";
+        SWARNING("HTTP parameter \"{}\" value \"{}\" is not an integer", param,
+                 value);
       }
       continue;
     }
 
     if (param == "compression") {
-      int compression;
-      if (value.getAsInteger(10, compression)) {
-        response << param << ": \"invalid integer\"\r\n";
-        SWARNING("HTTP parameter \"" << param << "\" value \"" << value
-                                     << "\" is not an integer");
-        continue;
-      } else {
-        m_compression = compression;
+      if (auto v = wpi::parse_integer<int>(value, 10)) {
+        m_compression = v.value();
         response << param << ": \"ok\"\r\n";
+      } else {
+        response << param << ": \"invalid integer\"\r\n";
+        SWARNING("HTTP parameter \"{}\" value \"{}\" is not an integer", param,
+                 value);
       }
       continue;
     }
@@ -300,7 +291,7 @@ bool MjpegServerImpl::ConnThread::ProcessCommand(wpi::raw_ostream& os,
     auto prop = source.GetPropertyIndex(param);
     if (!prop) {
       response << param << ": \"ignored\"\r\n";
-      SWARNING("ignoring HTTP parameter \"" << param << "\"");
+      SWARNING("ignoring HTTP parameter \"{}\"", param);
       continue;
     }
 
@@ -310,21 +301,20 @@ bool MjpegServerImpl::ConnThread::ProcessCommand(wpi::raw_ostream& os,
       case CS_PROP_BOOLEAN:
       case CS_PROP_INTEGER:
       case CS_PROP_ENUM: {
-        int val = 0;
-        if (value.getAsInteger(10, val)) {
-          response << param << ": \"invalid integer\"\r\n";
-          SWARNING("HTTP parameter \"" << param << "\" value \"" << value
-                                       << "\" is not an integer");
+        if (auto v = wpi::parse_integer<int>(value, 10)) {
+          fmt::print(response, "{}: {}\r\n", param, v.value());
+          SDEBUG4("HTTP parameter \"{}\" value {}", param, value);
+          source.SetProperty(prop, v.value(), &status);
         } else {
-          response << param << ": " << val << "\r\n";
-          SDEBUG4("HTTP parameter \"" << param << "\" value " << value);
-          source.SetProperty(prop, val, &status);
+          response << param << ": \"invalid integer\"\r\n";
+          SWARNING("HTTP parameter \"{}\" value \"{}\" is not an integer",
+                   param, value);
         }
         break;
       }
       case CS_PROP_STRING: {
         response << param << ": \"ok\"\r\n";
-        SDEBUG4("HTTP parameter \"" << param << "\" value \"" << value << "\"");
+        SDEBUG4("HTTP parameter \"{}\" value \"{}\"", param, value);
         source.SetStringProperty(prop, value, &status);
         break;
       }
@@ -362,17 +352,17 @@ void MjpegServerImpl::ConnThread::SendHTML(wpi::raw_ostream& os,
   for (auto prop : source.EnumerateProperties(properties_vec, &status)) {
     wpi::SmallString<128> name_buf;
     auto name = source.GetPropertyName(prop, name_buf, &status);
-    if (name.startswith("raw_")) {
+    if (wpi::starts_with(name, "raw_")) {
       continue;
     }
     auto kind = source.GetPropertyKind(prop);
-    os << "<p />"
-       << "<label for=\"" << name << "\">" << name << "</label>\n";
+    fmt::print(os, "<p /><label for=\"{0}\">{0}</label>\n", name);
     switch (kind) {
       case CS_PROP_BOOLEAN:
-        os << "<input id=\"" << name
-           << "\" type=\"checkbox\" onclick=\"update('" << name
-           << "', this.checked ? 1 : 0)\" ";
+        fmt::print(os,
+                   "<input id=\"{0}\" type=\"checkbox\" "
+                   "onclick=\"update('{0}', this.checked ? 1 : 0)\" ",
+                   name);
         if (source.GetProperty(prop, &status) != 0) {
           os << "checked />\n";
         } else {
@@ -384,12 +374,13 @@ void MjpegServerImpl::ConnThread::SendHTML(wpi::raw_ostream& os,
         auto min = source.GetPropertyMin(prop, &status);
         auto max = source.GetPropertyMax(prop, &status);
         auto step = source.GetPropertyStep(prop, &status);
-        os << "<input type=\"range\" min=\"" << min << "\" max=\"" << max
-           << "\" value=\"" << valI << "\" id=\"" << name << "\" step=\""
-           << step << "\" oninput=\"updateInt('#" << name << "op', '" << name
-           << "', value)\" />\n";
-        os << "<output for=\"" << name << "\" id=\"" << name << "op\">" << valI
-           << "</output>\n";
+        fmt::print(os,
+                   "<input type=\"range\" min=\"{1}\" max=\"{2}\" "
+                   "value=\"{3}\" id=\"{0}\" step=\"{4}\" "
+                   "oninput=\"updateInt('#{0}op', '{0}', value)\" />\n",
+                   name, min, max, valI, step);
+        fmt::print(os, "<output for=\"{0}\" id=\"{0}op\">{1}</output>\n", name,
+                   valI);
         break;
       }
       case CS_PROP_ENUM: {
@@ -404,26 +395,30 @@ void MjpegServerImpl::ConnThread::SendHTML(wpi::raw_ostream& os,
           // replace any non-printable characters in name with spaces
           wpi::SmallString<128> ch_name;
           for (char ch : *choice) {
-            ch_name.push_back(std::isprint(ch) ? ch : ' ');
+            ch_name.push_back(wpi::isPrint(ch) ? ch : ' ');
           }
-          os << "<input id=\"" << name << j << "\" type=\"radio\" name=\""
-             << name << "\" value=\"" << ch_name << "\" onclick=\"update('"
-             << name << "', " << j << ")\"";
+          fmt::print(os,
+                     "<input id=\"{0}{1}\" type=\"radio\" name=\"{0}\" "
+                     "value=\"{2}\" onclick=\"update('{0}', {1})\"",
+                     name, j, ch_name);
           if (j == valE) {
             os << " checked";
           }
-          os << " /><label for=\"" << name << j << "\">" << ch_name
-             << "</label>\n";
+          fmt::print(os, " /><label for=\"{}{}\">{}</label>\n", name, j,
+                     ch_name);
         }
         break;
       }
       case CS_PROP_STRING: {
         wpi::SmallString<128> strval_buf;
-        os << "<input type=\"text\" id=\"" << name << "box\" name=\"" << name
-           << "\" value=\""
-           << source.GetStringProperty(prop, strval_buf, &status) << "\" />\n";
-        os << "<input type=\"button\" value =\"Submit\" onclick=\"update('"
-           << name << "', " << name << "box.value)\" />\n";
+        fmt::print(os,
+                   "<input type=\"text\" id=\"{0}box\" name=\"{0}\" "
+                   "value=\"{1}\" />\n",
+                   name, source.GetStringProperty(prop, strval_buf, &status));
+        fmt::print(os,
+                   "<input type=\"button\" value =\"Submit\" "
+                   "onclick=\"update('{0}', {0}box.value)\" />\n",
+                   name);
         break;
       }
       default:
@@ -469,10 +464,8 @@ void MjpegServerImpl::ConnThread::SendHTML(wpi::raw_ostream& os,
         os << "unknown";
         break;
     }
-    os << "</td><td>" << mode.width;
-    os << "</td><td>" << mode.height;
-    os << "</td><td>" << mode.fps;
-    os << "</td></tr>";
+    fmt::print(os, "</td><td>{}</td><td>{}</td><td>{}</td></tr>", mode.width,
+               mode.height, mode.fps);
   }
   os << "</table>\n";
   os << endRootPage << "\r\n";
@@ -500,20 +493,21 @@ void MjpegServerImpl::ConnThread::SendJSON(wpi::raw_ostream& os,
     wpi::SmallString<128> name_buf;
     auto name = source.GetPropertyName(prop, name_buf, &status);
     auto kind = source.GetPropertyKind(prop);
-    os << "\n\"name\": \"" << name << '"';
-    os << ",\n\"id\": \"" << prop << '"';
-    os << ",\n\"type\": \"" << kind << '"';
-    os << ",\n\"min\": \"" << source.GetPropertyMin(prop, &status) << '"';
-    os << ",\n\"max\": \"" << source.GetPropertyMax(prop, &status) << '"';
-    os << ",\n\"step\": \"" << source.GetPropertyStep(prop, &status) << '"';
-    os << ",\n\"default\": \"" << source.GetPropertyDefault(prop, &status)
-       << '"';
+    fmt::print(os, "\n\"name\": \"{}\"", name);
+    fmt::print(os, ",\n\"id\": \"{}\"", prop);
+    fmt::print(os, ",\n\"type\": \"{}\"", kind);
+    fmt::print(os, ",\n\"min\": \"{}\"", source.GetPropertyMin(prop, &status));
+    fmt::print(os, ",\n\"max\": \"{}\"", source.GetPropertyMax(prop, &status));
+    fmt::print(os, ",\n\"step\": \"{}\"",
+               source.GetPropertyStep(prop, &status));
+    fmt::print(os, ",\n\"default\": \"{}\"",
+               source.GetPropertyDefault(prop, &status));
     os << ",\n\"value\": \"";
     switch (kind) {
       case CS_PROP_BOOLEAN:
       case CS_PROP_INTEGER:
       case CS_PROP_ENUM:
-        os << source.GetProperty(prop, &status);
+        fmt::print(os, "{}", source.GetProperty(prop, &status));
         break;
       case CS_PROP_STRING: {
         wpi::SmallString<128> strval_buf;
@@ -543,7 +537,7 @@ void MjpegServerImpl::ConnThread::SendJSON(wpi::raw_ostream& os,
         for (char ch : *choice) {
           ch_name.push_back(std::isprint(ch) ? ch : ' ');
         }
-        os << '"' << j << "\": \"" << ch_name << '"';
+        fmt::print(os, "\"{}\": \"{}\"", j, ch_name);
       }
       os << "}\n";
     }
@@ -579,29 +573,26 @@ void MjpegServerImpl::ConnThread::SendJSON(wpi::raw_ostream& os,
         os << "unknown";
         break;
     }
-    os << "\",\n\"width\": \"" << mode.width << '"';
-    os << ",\n\"height\": \"" << mode.height << '"';
-    os << ",\n\"fps\": \"" << mode.fps << '"';
+    fmt::print(os, "\",\n\"width\": \"{}\"", mode.width);
+    fmt::print(os, ",\n\"height\": \"{}\"", mode.height);
+    fmt::print(os, ",\n\"fps\": \"{}\"", mode.fps);
     os << '}';
   }
   os << "\n]\n}\n";
   os.flush();
 }
 
-MjpegServerImpl::MjpegServerImpl(const wpi::Twine& name, wpi::Logger& logger,
+MjpegServerImpl::MjpegServerImpl(std::string_view name, wpi::Logger& logger,
                                  Notifier& notifier, Telemetry& telemetry,
-                                 const wpi::Twine& listenAddress, int port,
+                                 std::string_view listenAddress, int port,
                                  std::unique_ptr<wpi::NetworkAcceptor> acceptor)
     : SinkImpl{name, logger, notifier, telemetry},
-      m_listenAddress(listenAddress.str()),
+      m_listenAddress(listenAddress),
       m_port(port),
       m_acceptor{std::move(acceptor)} {
   m_active = true;
 
-  wpi::SmallString<128> descBuf;
-  wpi::raw_svector_ostream desc{descBuf};
-  desc << "HTTP Server on port " << port;
-  SetDescription(desc.str());
+  SetDescription(fmt::format("HTTP Server on port {}", port));
 
   // Create properties
   m_widthProp = CreateProperty("width", [] {
@@ -659,7 +650,7 @@ void MjpegServerImpl::Stop() {
 // Send HTTP response and a stream of JPG-frames
 void MjpegServerImpl::ConnThread::SendStream(wpi::raw_socket_ostream& os) {
   if (m_noStreaming) {
-    SERROR("Too many simultaneous client streams");
+    SERROR("{}", "Too many simultaneous client streams");
     SendError(os, 503, "Too many simultaneous streams");
     return;
   }
@@ -672,7 +663,7 @@ void MjpegServerImpl::ConnThread::SendStream(wpi::raw_socket_ostream& os) {
   SendHeader(oss, 200, "OK", "multipart/x-mixed-replace;boundary=" BOUNDARY);
   os << oss.str();
 
-  SDEBUG("Headers send, sending stream now");
+  SDEBUG("{}", "Headers send, sending stream now");
 
   Frame::Time lastFrameTime = 0;
   Frame::Time timePerFrame = 0;
@@ -694,7 +685,7 @@ void MjpegServerImpl::ConnThread::SendStream(wpi::raw_socket_ostream& os) {
       std::this_thread::sleep_for(std::chrono::milliseconds(200));
       continue;
     }
-    SDEBUG4("waiting for frame");
+    SDEBUG4("{}", "waiting for frame");
     Frame frame = source->GetNextFrame(0.225);  // blocks
     if (!m_active) {
       break;
@@ -757,7 +748,7 @@ void MjpegServerImpl::ConnThread::SendStream(wpi::raw_socket_ostream& os) {
         continue;
     }
 
-    SDEBUG4("sending frame size=" << size << " addDHT=" << addDHT);
+    SDEBUG4("sending frame size={} addDHT={}", size, addDHT);
 
     // print the individual mimetype and the length
     // sending the content-length fixes random stream disruption observed
@@ -766,18 +757,18 @@ void MjpegServerImpl::ConnThread::SendStream(wpi::raw_socket_ostream& os) {
     double timestamp = lastFrameTime / 1000000.0;
     header.clear();
     oss << "\r\n--" BOUNDARY "\r\n"
-        << "Content-Type: image/jpeg\r\n"
-        << "Content-Length: " << size << "\r\n"
-        << "X-Timestamp: " << timestamp << "\r\n"
-        << "\r\n";
+        << "Content-Type: image/jpeg\r\n";
+    fmt::print(oss, "Content-Length: {}\r\n", size);
+    fmt::print(oss, "X-Timestamp: {}\r\n", timestamp);
+    oss << "\r\n";
     os << oss.str();
     if (addDHT) {
       // Insert DHT data immediately before SOF
-      os << wpi::StringRef(data, locSOF);
+      os << std::string_view(data, locSOF);
       os << JpegGetDHT();
-      os << wpi::StringRef(data + locSOF, image->size() - locSOF);
+      os << std::string_view(data + locSOF, image->size() - locSOF);
     } else {
-      os << wpi::StringRef(data, size);
+      os << std::string_view(data, size);
     }
     // os.flush();
   }
@@ -790,48 +781,50 @@ void MjpegServerImpl::ConnThread::ProcessRequest() {
 
   // Read the request string from the stream
   wpi::SmallString<128> reqBuf;
-  wpi::StringRef req = is.getline(reqBuf, 4096);
+  std::string_view req = is.getline(reqBuf, 4096);
   if (is.has_error()) {
-    SDEBUG("error getting request string");
+    SDEBUG("{}", "error getting request string");
     return;
   }
 
   enum { kCommand, kStream, kGetSettings, kGetSourceConfig, kRootPage } kind;
-  wpi::StringRef parameters;
+  std::string_view parameters;
   size_t pos;
 
-  SDEBUG("HTTP request: '" << req << "'\n");
+  SDEBUG("HTTP request: '{}'\n", req);
 
   // Determine request kind.  Most of these are for mjpgstreamer
   // compatibility, others are for Axis camera compatibility.
-  if ((pos = req.find("POST /stream")) != wpi::StringRef::npos) {
+  if ((pos = req.find("POST /stream")) != std::string_view::npos) {
     kind = kStream;
     parameters = req.substr(req.find('?', pos + 12)).substr(1);
-  } else if ((pos = req.find("GET /?action=stream")) != wpi::StringRef::npos) {
+  } else if ((pos = req.find("GET /?action=stream")) !=
+             std::string_view::npos) {
     kind = kStream;
     parameters = req.substr(req.find('&', pos + 19)).substr(1);
-  } else if ((pos = req.find("GET /stream.mjpg")) != wpi::StringRef::npos) {
+  } else if ((pos = req.find("GET /stream.mjpg")) != std::string_view::npos) {
     kind = kStream;
     parameters = req.substr(req.find('?', pos + 16)).substr(1);
-  } else if (req.find("GET /settings") != wpi::StringRef::npos &&
-             req.find(".json") != wpi::StringRef::npos) {
+  } else if (req.find("GET /settings") != std::string_view::npos &&
+             req.find(".json") != std::string_view::npos) {
     kind = kGetSettings;
-  } else if (req.find("GET /config") != wpi::StringRef::npos &&
-             req.find(".json") != wpi::StringRef::npos) {
+  } else if (req.find("GET /config") != std::string_view::npos &&
+             req.find(".json") != std::string_view::npos) {
     kind = kGetSourceConfig;
-  } else if (req.find("GET /input") != wpi::StringRef::npos &&
-             req.find(".json") != wpi::StringRef::npos) {
+  } else if (req.find("GET /input") != std::string_view::npos &&
+             req.find(".json") != std::string_view::npos) {
     kind = kGetSettings;
-  } else if (req.find("GET /output") != wpi::StringRef::npos &&
-             req.find(".json") != wpi::StringRef::npos) {
+  } else if (req.find("GET /output") != std::string_view::npos &&
+             req.find(".json") != std::string_view::npos) {
     kind = kGetSettings;
-  } else if ((pos = req.find("GET /?action=command")) != wpi::StringRef::npos) {
+  } else if ((pos = req.find("GET /?action=command")) !=
+             std::string_view::npos) {
     kind = kCommand;
     parameters = req.substr(req.find('&', pos + 20)).substr(1);
-  } else if (req.find("GET / ") != wpi::StringRef::npos || req == "GET /\n") {
+  } else if (req.find("GET / ") != std::string_view::npos || req == "GET /\n") {
     kind = kRootPage;
   } else {
-    SDEBUG("HTTP request resource not found");
+    SDEBUG("{}", "HTTP request resource not found");
     SendError(os, 404, "Resource not found");
     return;
   }
@@ -841,13 +834,13 @@ void MjpegServerImpl::ConnThread::ProcessRequest() {
       "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_"
       "-=&1234567890%./");
   parameters = parameters.substr(0, pos);
-  SDEBUG("command parameters: \"" << parameters << "\"");
+  SDEBUG("command parameters: \"{}\"", parameters);
 
   // Read the rest of the HTTP request.
   // The end of the request is marked by a single, empty line
   wpi::SmallString<128> lineBuf;
   for (;;) {
-    if (is.getline(lineBuf, 4096).startswith("\n")) {
+    if (wpi::starts_with(is.getline(lineBuf, 4096), "\n")) {
       break;
     }
     if (is.has_error()) {
@@ -859,7 +852,7 @@ void MjpegServerImpl::ConnThread::ProcessRequest() {
   switch (kind) {
     case kStream:
       if (auto source = GetSource()) {
-        SDEBUG("request for stream " << source->GetName());
+        SDEBUG("request for stream {}", source->GetName());
         if (!ProcessCommand(os, *source, parameters, false)) {
           return;
         }
@@ -873,11 +866,11 @@ void MjpegServerImpl::ConnThread::ProcessRequest() {
         SendHeader(os, 200, "OK", "text/plain");
         os << "Ignored due to no connected source."
            << "\r\n";
-        SDEBUG("Ignored due to no connected source.");
+        SDEBUG("{}", "Ignored due to no connected source.");
       }
       break;
     case kGetSettings:
-      SDEBUG("request for JSON file");
+      SDEBUG("{}", "request for JSON file");
       if (auto source = GetSource()) {
         SendJSON(os, *source, true);
       } else {
@@ -885,7 +878,7 @@ void MjpegServerImpl::ConnThread::ProcessRequest() {
       }
       break;
     case kGetSourceConfig:
-      SDEBUG("request for JSON file");
+      SDEBUG("{}", "request for JSON file");
       if (auto source = GetSource()) {
         SendHeader(os, 200, "OK", "application/json");
         CS_Status status = CS_OK;
@@ -896,7 +889,7 @@ void MjpegServerImpl::ConnThread::ProcessRequest() {
       }
       break;
     case kRootPage:
-      SDEBUG("request for root page");
+      SDEBUG("{}", "request for root page");
       SendHeader(os, 200, "OK", "text/html");
       if (auto source = GetSource()) {
         SendHTML(os, *source, false);
@@ -907,7 +900,7 @@ void MjpegServerImpl::ConnThread::ProcessRequest() {
       break;
   }
 
-  SDEBUG("leaving HTTP client thread");
+  SDEBUG("{}", "leaving HTTP client thread");
 }
 
 // worker thread for clients that connected to this server
@@ -934,7 +927,7 @@ void MjpegServerImpl::ServerThreadMain() {
     return;
   }
 
-  SDEBUG("waiting for clients to connect");
+  SDEBUG("{}", "waiting for clients to connect");
   while (m_active) {
     auto stream = m_acceptor->accept();
     if (!stream) {
@@ -945,7 +938,7 @@ void MjpegServerImpl::ServerThreadMain() {
       return;
     }
 
-    SDEBUG("client connection from " << stream->getPeerIP());
+    SDEBUG("client connection from {}", stream->getPeerIP());
 
     auto source = GetSource();
 
@@ -984,7 +977,7 @@ void MjpegServerImpl::ServerThreadMain() {
     thr->m_cond.notify_one();
   }
 
-  SDEBUG("leaving server thread");
+  SDEBUG("{}", "leaving server thread");
 }
 
 void MjpegServerImpl::SetSourceImpl(std::shared_ptr<SourceImpl> source) {
@@ -1007,19 +1000,15 @@ void MjpegServerImpl::SetSourceImpl(std::shared_ptr<SourceImpl> source) {
 
 namespace cs {
 
-CS_Sink CreateMjpegServer(const wpi::Twine& name,
-                          const wpi::Twine& listenAddress, int port,
-                          CS_Status* status) {
+CS_Sink CreateMjpegServer(std::string_view name, std::string_view listenAddress,
+                          int port, CS_Status* status) {
   auto& inst = Instance::GetInstance();
-  wpi::SmallString<128> listenAddressBuf;
   return inst.CreateSink(
       CS_SINK_MJPEG,
       std::make_shared<MjpegServerImpl>(
           name, inst.logger, inst.notifier, inst.telemetry, listenAddress, port,
-          std::unique_ptr<wpi::NetworkAcceptor>(new wpi::TCPAcceptor(
-              port,
-              listenAddress.toNullTerminatedStringRef(listenAddressBuf).data(),
-              inst.logger))));
+          std::unique_ptr<wpi::NetworkAcceptor>(
+              new wpi::TCPAcceptor(port, listenAddress, inst.logger))));
 }
 
 std::string GetMjpegServerListenAddress(CS_Sink sink, CS_Status* status) {
diff --git a/cscore/src/main/native/cpp/MjpegServerImpl.h b/cscore/src/main/native/cpp/MjpegServerImpl.h
index bc4d232e62..e323e69b48 100644
--- a/cscore/src/main/native/cpp/MjpegServerImpl.h
+++ b/cscore/src/main/native/cpp/MjpegServerImpl.h
@@ -8,6 +8,7 @@
 #include <atomic>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <thread>
 #include <vector>
 
@@ -15,7 +16,6 @@
 #include <wpi/NetworkStream.h>
 #include <wpi/SafeThread.h>
 #include <wpi/SmallVector.h>
-#include <wpi/Twine.h>
 #include <wpi/raw_istream.h>
 #include <wpi/raw_ostream.h>
 #include <wpi/raw_socket_ostream.h>
@@ -28,9 +28,9 @@ class SourceImpl;
 
 class MjpegServerImpl : public SinkImpl {
  public:
-  MjpegServerImpl(const wpi::Twine& name, wpi::Logger& logger,
+  MjpegServerImpl(std::string_view name, wpi::Logger& logger,
                   Notifier& notifier, Telemetry& telemetry,
-                  const wpi::Twine& listenAddress, int port,
+                  std::string_view listenAddress, int port,
                   std::unique_ptr<wpi::NetworkAcceptor> acceptor);
   ~MjpegServerImpl() override;
 
diff --git a/cscore/src/main/native/cpp/Notifier.cpp b/cscore/src/main/native/cpp/Notifier.cpp
index 318e1b25ff..371189634d 100644
--- a/cscore/src/main/native/cpp/Notifier.cpp
+++ b/cscore/src/main/native/cpp/Notifier.cpp
@@ -32,7 +32,7 @@ unsigned int Notifier::AddPolled(unsigned int pollerUid, int eventMask) {
   return DoAdd(pollerUid, eventMask);
 }
 
-void Notifier::NotifySource(const wpi::Twine& name, CS_Source source,
+void Notifier::NotifySource(std::string_view name, CS_Source source,
                             CS_EventKind kind) {
   Send(UINT_MAX, name, source, static_cast<RawEvent::Kind>(kind));
 }
@@ -49,9 +49,9 @@ void Notifier::NotifySourceVideoMode(const SourceImpl& source,
 }
 
 void Notifier::NotifySourceProperty(const SourceImpl& source, CS_EventKind kind,
-                                    const wpi::Twine& propertyName,
-                                    int property, CS_PropertyKind propertyKind,
-                                    int value, const wpi::Twine& valueStr) {
+                                    std::string_view propertyName, int property,
+                                    CS_PropertyKind propertyKind, int value,
+                                    std::string_view valueStr) {
   auto handleData = Instance::GetInstance().FindSource(source);
   Send(UINT_MAX, propertyName, handleData.first,
        static_cast<RawEvent::Kind>(kind),
@@ -59,7 +59,7 @@ void Notifier::NotifySourceProperty(const SourceImpl& source, CS_EventKind kind,
        value, valueStr);
 }
 
-void Notifier::NotifySink(const wpi::Twine& name, CS_Sink sink,
+void Notifier::NotifySink(std::string_view name, CS_Sink sink,
                           CS_EventKind kind) {
   Send(UINT_MAX, name, sink, static_cast<RawEvent::Kind>(kind));
 }
@@ -69,7 +69,7 @@ void Notifier::NotifySink(const SinkImpl& sink, CS_EventKind kind) {
   NotifySink(sink.GetName(), handleData.first, kind);
 }
 
-void Notifier::NotifySinkSourceChanged(const wpi::Twine& name, CS_Sink sink,
+void Notifier::NotifySinkSourceChanged(std::string_view name, CS_Sink sink,
                                        CS_Source source) {
   RawEvent event{name, sink, RawEvent::kSinkSourceChanged};
   event.sourceHandle = source;
@@ -77,9 +77,9 @@ void Notifier::NotifySinkSourceChanged(const wpi::Twine& name, CS_Sink sink,
 }
 
 void Notifier::NotifySinkProperty(const SinkImpl& sink, CS_EventKind kind,
-                                  const wpi::Twine& propertyName, int property,
+                                  std::string_view propertyName, int property,
                                   CS_PropertyKind propertyKind, int value,
-                                  const wpi::Twine& valueStr) {
+                                  std::string_view valueStr) {
   auto handleData = Instance::GetInstance().FindSink(sink);
   Send(UINT_MAX, propertyName, handleData.first,
        static_cast<RawEvent::Kind>(kind),
diff --git a/cscore/src/main/native/cpp/Notifier.h b/cscore/src/main/native/cpp/Notifier.h
index 3a5533ac05..c0f7abcf39 100644
--- a/cscore/src/main/native/cpp/Notifier.h
+++ b/cscore/src/main/native/cpp/Notifier.h
@@ -65,22 +65,21 @@ class Notifier : public wpi::CallbackManager<Notifier, impl::NotifierThread> {
   unsigned int AddPolled(unsigned int pollerUid, int eventMask);
 
   // Notification events
-  void NotifySource(const wpi::Twine& name, CS_Source source,
-                    CS_EventKind kind);
+  void NotifySource(std::string_view name, CS_Source source, CS_EventKind kind);
   void NotifySource(const SourceImpl& source, CS_EventKind kind);
   void NotifySourceVideoMode(const SourceImpl& source, const VideoMode& mode);
   void NotifySourceProperty(const SourceImpl& source, CS_EventKind kind,
-                            const wpi::Twine& propertyName, int property,
+                            std::string_view propertyName, int property,
                             CS_PropertyKind propertyKind, int value,
-                            const wpi::Twine& valueStr);
-  void NotifySink(const wpi::Twine& name, CS_Sink sink, CS_EventKind kind);
+                            std::string_view valueStr);
+  void NotifySink(std::string_view name, CS_Sink sink, CS_EventKind kind);
   void NotifySink(const SinkImpl& sink, CS_EventKind kind);
-  void NotifySinkSourceChanged(const wpi::Twine& name, CS_Sink sink,
+  void NotifySinkSourceChanged(std::string_view name, CS_Sink sink,
                                CS_Source source);
   void NotifySinkProperty(const SinkImpl& sink, CS_EventKind kind,
-                          const wpi::Twine& propertyName, int property,
+                          std::string_view propertyName, int property,
                           CS_PropertyKind propertyKind, int value,
-                          const wpi::Twine& valueStr);
+                          std::string_view valueStr);
   void NotifyNetworkInterfacesChanged();
   void NotifyTelemetryUpdated();
   void NotifyUsbCamerasChanged();
diff --git a/cscore/src/main/native/cpp/PropertyContainer.cpp b/cscore/src/main/native/cpp/PropertyContainer.cpp
index f86280b317..d95c06edfa 100644
--- a/cscore/src/main/native/cpp/PropertyContainer.cpp
+++ b/cscore/src/main/native/cpp/PropertyContainer.cpp
@@ -11,15 +11,14 @@
 
 using namespace cs;
 
-int PropertyContainer::GetPropertyIndex(const wpi::Twine& name) const {
+int PropertyContainer::GetPropertyIndex(std::string_view name) const {
   // We can't fail, so instead we create a new index if caching fails.
   CS_Status status = 0;
   if (!m_properties_cached) {
     CacheProperties(&status);
   }
   std::scoped_lock lock(m_mutex);
-  wpi::SmallVector<char, 64> nameBuf;
-  int& ndx = m_properties[name.toStringRef(nameBuf)];
+  int& ndx = m_properties[name];
   if (ndx == 0) {
     // create a new index
     ndx = m_propertyData.size() + 1;
@@ -55,7 +54,7 @@ CS_PropertyKind PropertyContainer::GetPropertyKind(int property) const {
   return prop->propKind;
 }
 
-wpi::StringRef PropertyContainer::GetPropertyName(
+std::string_view PropertyContainer::GetPropertyName(
     int property, wpi::SmallVectorImpl<char>& buf, CS_Status* status) const {
   if (!m_properties_cached && !CacheProperties(status)) {
     return {};
@@ -108,7 +107,7 @@ void PropertyContainer::SetProperty(int property, int value,
     return;
   }
 
-  UpdatePropertyValue(property, false, value, wpi::Twine{});
+  UpdatePropertyValue(property, false, value, {});
 }
 
 int PropertyContainer::GetPropertyMin(int property, CS_Status* status) const {
@@ -164,7 +163,7 @@ int PropertyContainer::GetPropertyDefault(int property,
   return prop->defaultValue;
 }
 
-wpi::StringRef PropertyContainer::GetStringProperty(
+std::string_view PropertyContainer::GetStringProperty(
     int property, wpi::SmallVectorImpl<char>& buf, CS_Status* status) const {
   if (!m_properties_cached && !CacheProperties(status)) {
     return {};
@@ -181,10 +180,10 @@ wpi::StringRef PropertyContainer::GetStringProperty(
   }
   buf.clear();
   buf.append(prop->valueStr.begin(), prop->valueStr.end());
-  return wpi::StringRef(buf.data(), buf.size());
+  return {buf.data(), buf.size()};
 }
 
-void PropertyContainer::SetStringProperty(int property, const wpi::Twine& value,
+void PropertyContainer::SetStringProperty(int property, std::string_view value,
                                           CS_Status* status) {
   std::scoped_lock lock(m_mutex);
   auto prop = GetProperty(property);
@@ -225,7 +224,7 @@ std::vector<std::string> PropertyContainer::GetEnumPropertyChoices(
 }
 
 std::unique_ptr<PropertyImpl> PropertyContainer::CreateEmptyProperty(
-    const wpi::Twine& name) const {
+    std::string_view name) const {
   return std::make_unique<PropertyImpl>(name);
 }
 
@@ -237,16 +236,15 @@ bool PropertyContainer::CacheProperties(CS_Status* status) const {
 
 bool PropertyContainer::SetPropertiesJson(const wpi::json& config,
                                           wpi::Logger& logger,
-                                          wpi::StringRef logName,
+                                          std::string_view logName,
                                           CS_Status* status) {
   for (auto&& prop : config) {
     std::string name;
     try {
       name = prop.at("name").get<std::string>();
     } catch (const wpi::json::exception& e) {
-      WPI_WARNING(logger,
-                  logName << ": SetConfigJson: could not read property name: "
-                          << e.what());
+      WPI_WARNING(logger, "{}: SetConfigJson: could not read property name: {}",
+                  logName, e.what());
       continue;
     }
     int n = GetPropertyIndex(name);
@@ -254,24 +252,24 @@ bool PropertyContainer::SetPropertiesJson(const wpi::json& config,
       auto& v = prop.at("value");
       if (v.is_string()) {
         std::string val = v.get<std::string>();
-        WPI_INFO(logger, logName << ": SetConfigJson: setting property '"
-                                 << name << "' to '" << val << '\'');
+        WPI_INFO(logger, "{}: SetConfigJson: setting property '{}' to '{}'",
+                 logName, name, val);
         SetStringProperty(n, val, status);
       } else if (v.is_boolean()) {
         bool val = v.get<bool>();
-        WPI_INFO(logger, logName << ": SetConfigJson: setting property '"
-                                 << name << "' to " << val);
+        WPI_INFO(logger, "{}: SetConfigJson: setting property '{}' to {}",
+                 logName, name, val);
         SetProperty(n, val, status);
       } else {
         int val = v.get<int>();
-        WPI_INFO(logger, logName << ": SetConfigJson: setting property '"
-                                 << name << "' to " << val);
+        WPI_INFO(logger, "{}: SetConfigJson: setting property '{}' to {}",
+                 logName, name, val);
         SetProperty(n, val, status);
       }
     } catch (const wpi::json::exception& e) {
       WPI_WARNING(logger,
-                  logName << ": SetConfigJson: could not read property value: "
-                          << e.what());
+                  "{}: SetConfigJson: could not read property value: {}",
+                  logName, e.what());
       continue;
     }
   }
diff --git a/cscore/src/main/native/cpp/PropertyContainer.h b/cscore/src/main/native/cpp/PropertyContainer.h
index f1c71ea6b0..f09ea23c7b 100644
--- a/cscore/src/main/native/cpp/PropertyContainer.h
+++ b/cscore/src/main/native/cpp/PropertyContainer.h
@@ -9,13 +9,11 @@
 #include <cstddef>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <wpi/ArrayRef.h>
-#include <wpi/SmallVector.h>
 #include <wpi/StringMap.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 #include <wpi/mutex.h>
 
 #include "PropertyImpl.h"
@@ -23,6 +21,8 @@
 
 namespace wpi {
 class Logger;
+template <typename T>
+class SmallVectorImpl;
 class json;
 }  // namespace wpi
 
@@ -32,28 +32,29 @@ class PropertyContainer {
  public:
   virtual ~PropertyContainer() = default;
 
-  int GetPropertyIndex(const wpi::Twine& name) const;
+  int GetPropertyIndex(std::string_view name) const;
   wpi::ArrayRef<int> EnumerateProperties(wpi::SmallVectorImpl<int>& vec,
                                          CS_Status* status) const;
   CS_PropertyKind GetPropertyKind(int property) const;
-  wpi::StringRef GetPropertyName(int property, wpi::SmallVectorImpl<char>& buf,
-                                 CS_Status* status) const;
+  std::string_view GetPropertyName(int property,
+                                   wpi::SmallVectorImpl<char>& buf,
+                                   CS_Status* status) const;
   int GetProperty(int property, CS_Status* status) const;
   virtual void SetProperty(int property, int value, CS_Status* status);
   int GetPropertyMin(int property, CS_Status* status) const;
   int GetPropertyMax(int property, CS_Status* status) const;
   int GetPropertyStep(int property, CS_Status* status) const;
   int GetPropertyDefault(int property, CS_Status* status) const;
-  wpi::StringRef GetStringProperty(int property,
-                                   wpi::SmallVectorImpl<char>& buf,
-                                   CS_Status* status) const;
-  virtual void SetStringProperty(int property, const wpi::Twine& value,
+  std::string_view GetStringProperty(int property,
+                                     wpi::SmallVectorImpl<char>& buf,
+                                     CS_Status* status) const;
+  virtual void SetStringProperty(int property, std::string_view value,
                                  CS_Status* status);
   std::vector<std::string> GetEnumPropertyChoices(int property,
                                                   CS_Status* status) const;
 
   bool SetPropertiesJson(const wpi::json& config, wpi::Logger& logger,
-                         wpi::StringRef logName, CS_Status* status);
+                         std::string_view logName, CS_Status* status);
   wpi::json GetPropertiesJsonObject(CS_Status* status);
 
  protected:
@@ -76,10 +77,9 @@ class PropertyContainer {
   // @tparam NewFunc functor that returns a std::unique_ptr<PropertyImpl>
   // @tparam UpdateFunc functor that takes a PropertyImpl&.
   template <typename NewFunc, typename UpdateFunc>
-  int CreateOrUpdateProperty(const wpi::Twine& name, NewFunc newFunc,
+  int CreateOrUpdateProperty(std::string_view name, NewFunc newFunc,
                              UpdateFunc updateFunc) {
-    wpi::SmallVector<char, 64> nameBuf;
-    int& ndx = m_properties[name.toStringRef(nameBuf)];
+    int& ndx = m_properties[name];
     if (ndx == 0) {
       // create a new index
       ndx = m_propertyData.size() + 1;
@@ -91,7 +91,7 @@ class PropertyContainer {
     return ndx;
   }
   template <typename NewFunc>
-  int CreateProperty(const wpi::Twine& name, NewFunc newFunc) {
+  int CreateProperty(std::string_view name, NewFunc newFunc) {
     return CreateOrUpdateProperty(name, newFunc, [](PropertyImpl&) {});
   }
 
@@ -100,7 +100,7 @@ class PropertyContainer {
   // Note: called with m_mutex held.
   // The default implementation simply creates a PropertyImpl object.
   virtual std::unique_ptr<PropertyImpl> CreateEmptyProperty(
-      const wpi::Twine& name) const;
+      std::string_view name) const;
 
   // Cache properties.  Implementations must return false and set status to
   // CS_SOURCE_IS_DISCONNECTED if not possible to cache.
@@ -111,7 +111,7 @@ class PropertyContainer {
 
   // Update property value; must be called with m_mutex held.
   virtual void UpdatePropertyValue(int property, bool setString, int value,
-                                   const wpi::Twine& valueStr) = 0;
+                                   std::string_view valueStr) = 0;
 
   // Whether CacheProperties() has been successful at least once (and thus
   // should not be called again)
diff --git a/cscore/src/main/native/cpp/PropertyImpl.cpp b/cscore/src/main/native/cpp/PropertyImpl.cpp
index 68977235d1..3c3663043c 100644
--- a/cscore/src/main/native/cpp/PropertyImpl.cpp
+++ b/cscore/src/main/native/cpp/PropertyImpl.cpp
@@ -6,18 +6,18 @@
 
 using namespace cs;
 
-PropertyImpl::PropertyImpl(const wpi::Twine& name_) : name{name_.str()} {}
-PropertyImpl::PropertyImpl(const wpi::Twine& name_, CS_PropertyKind kind_,
+PropertyImpl::PropertyImpl(std::string_view name_) : name{name_} {}
+PropertyImpl::PropertyImpl(std::string_view name_, CS_PropertyKind kind_,
                            int step_, int defaultValue_, int value_)
-    : name{name_.str()},
+    : name{name_},
       propKind{kind_},
       step{step_},
       defaultValue{defaultValue_},
       value{value_} {}
-PropertyImpl::PropertyImpl(const wpi::Twine& name_, CS_PropertyKind kind_,
+PropertyImpl::PropertyImpl(std::string_view name_, CS_PropertyKind kind_,
                            int minimum_, int maximum_, int step_,
                            int defaultValue_, int value_)
-    : name{name_.str()},
+    : name{name_},
       propKind{kind_},
       hasMinimum{true},
       hasMaximum{true},
@@ -43,11 +43,10 @@ void PropertyImpl::SetValue(int v) {
   }
 }
 
-void PropertyImpl::SetValue(const wpi::Twine& v) {
+void PropertyImpl::SetValue(std::string_view v) {
   bool valueChanged = false;
-  std::string vStr = v.str();
-  if (valueStr != vStr) {
-    valueStr = vStr;
+  if (valueStr != v) {
+    valueStr = v;
     valueChanged = true;
   }
   bool wasValueSet = valueSet;
diff --git a/cscore/src/main/native/cpp/PropertyImpl.h b/cscore/src/main/native/cpp/PropertyImpl.h
index ea9f057b8a..77e79082d7 100644
--- a/cscore/src/main/native/cpp/PropertyImpl.h
+++ b/cscore/src/main/native/cpp/PropertyImpl.h
@@ -6,11 +6,10 @@
 #define CSCORE_PROPERTYIMPL_H_
 
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <wpi/Signal.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 
 #include "cscore_c.h"
 
@@ -20,17 +19,17 @@ namespace cs {
 class PropertyImpl {
  public:
   PropertyImpl() = default;
-  explicit PropertyImpl(const wpi::Twine& name_);
-  PropertyImpl(const wpi::Twine& name_, CS_PropertyKind kind_, int step_,
+  explicit PropertyImpl(std::string_view name_);
+  PropertyImpl(std::string_view name_, CS_PropertyKind kind_, int step_,
                int defaultValue_, int value_);
-  PropertyImpl(const wpi::Twine& name_, CS_PropertyKind kind_, int minimum_,
+  PropertyImpl(std::string_view name_, CS_PropertyKind kind_, int minimum_,
                int maximum_, int step_, int defaultValue_, int value_);
   virtual ~PropertyImpl() = default;
   PropertyImpl(const PropertyImpl& oth) = delete;
   PropertyImpl& operator=(const PropertyImpl& oth) = delete;
 
   void SetValue(int v);
-  void SetValue(const wpi::Twine& v);
+  void SetValue(std::string_view v);
   void SetDefaultValue(int v);
 
   std::string name;
diff --git a/cscore/src/main/native/cpp/RawSinkImpl.cpp b/cscore/src/main/native/cpp/RawSinkImpl.cpp
index 4dbe7818a0..fbc1028f81 100644
--- a/cscore/src/main/native/cpp/RawSinkImpl.cpp
+++ b/cscore/src/main/native/cpp/RawSinkImpl.cpp
@@ -10,14 +10,14 @@
 
 using namespace cs;
 
-RawSinkImpl::RawSinkImpl(const wpi::Twine& name, wpi::Logger& logger,
+RawSinkImpl::RawSinkImpl(std::string_view name, wpi::Logger& logger,
                          Notifier& notifier, Telemetry& telemetry)
     : SinkImpl{name, logger, notifier, telemetry} {
   m_active = true;
   // m_thread = std::thread(&RawSinkImpl::ThreadMain, this);
 }
 
-RawSinkImpl::RawSinkImpl(const wpi::Twine& name, wpi::Logger& logger,
+RawSinkImpl::RawSinkImpl(std::string_view name, wpi::Logger& logger,
                          Notifier& notifier, Telemetry& telemetry,
                          std::function<void(uint64_t time)> processFrame)
     : SinkImpl{name, logger, notifier, telemetry} {}
@@ -127,7 +127,7 @@ void RawSinkImpl::ThreadMain() {
       std::this_thread::sleep_for(std::chrono::seconds(1));
       continue;
     }
-    SDEBUG4("waiting for frame");
+    SDEBUG4("{}", "waiting for frame");
     Frame frame = source->GetNextFrame();  // blocks
     if (!m_active) {
       break;
@@ -143,14 +143,14 @@ void RawSinkImpl::ThreadMain() {
 }
 
 namespace cs {
-CS_Sink CreateRawSink(const wpi::Twine& name, CS_Status* status) {
+CS_Sink CreateRawSink(std::string_view name, CS_Status* status) {
   auto& inst = Instance::GetInstance();
   return inst.CreateSink(CS_SINK_RAW,
                          std::make_shared<RawSinkImpl>(
                              name, inst.logger, inst.notifier, inst.telemetry));
 }
 
-CS_Sink CreateRawSinkCallback(const wpi::Twine& name,
+CS_Sink CreateRawSinkCallback(std::string_view name,
                               std::function<void(uint64_t time)> processFrame,
                               CS_Status* status) {
   auto& inst = Instance::GetInstance();
diff --git a/cscore/src/main/native/cpp/RawSinkImpl.h b/cscore/src/main/native/cpp/RawSinkImpl.h
index 5fc43de36e..6e8032a101 100644
--- a/cscore/src/main/native/cpp/RawSinkImpl.h
+++ b/cscore/src/main/native/cpp/RawSinkImpl.h
@@ -9,9 +9,9 @@
 
 #include <atomic>
 #include <functional>
+#include <string_view>
 #include <thread>
 
-#include <wpi/Twine.h>
 #include <wpi/condition_variable.h>
 
 #include "Frame.h"
@@ -23,9 +23,9 @@ class SourceImpl;
 
 class RawSinkImpl : public SinkImpl {
  public:
-  RawSinkImpl(const wpi::Twine& name, wpi::Logger& logger, Notifier& notifier,
+  RawSinkImpl(std::string_view name, wpi::Logger& logger, Notifier& notifier,
               Telemetry& telemetry);
-  RawSinkImpl(const wpi::Twine& name, wpi::Logger& logger, Notifier& notifier,
+  RawSinkImpl(std::string_view name, wpi::Logger& logger, Notifier& notifier,
               Telemetry& telemetry,
               std::function<void(uint64_t time)> processFrame);
   ~RawSinkImpl() override;
diff --git a/cscore/src/main/native/cpp/RawSourceImpl.cpp b/cscore/src/main/native/cpp/RawSourceImpl.cpp
index 87184d2534..9ce0628102 100644
--- a/cscore/src/main/native/cpp/RawSourceImpl.cpp
+++ b/cscore/src/main/native/cpp/RawSourceImpl.cpp
@@ -14,7 +14,7 @@
 
 using namespace cs;
 
-RawSourceImpl::RawSourceImpl(const wpi::Twine& name, wpi::Logger& logger,
+RawSourceImpl::RawSourceImpl(std::string_view name, wpi::Logger& logger,
                              Notifier& notifier, Telemetry& telemetry,
                              const VideoMode& mode)
     : ConfigurableSourceImpl{name, logger, notifier, telemetry, mode} {}
@@ -47,7 +47,7 @@ void RawSourceImpl::PutFrame(const CS_RawFrame& image) {
 }
 
 namespace cs {
-CS_Source CreateRawSource(const wpi::Twine& name, const VideoMode& mode,
+CS_Source CreateRawSource(std::string_view name, const VideoMode& mode,
                           CS_Status* status) {
   auto& inst = Instance::GetInstance();
   return inst.CreateSource(CS_SOURCE_RAW, std::make_shared<RawSourceImpl>(
diff --git a/cscore/src/main/native/cpp/RawSourceImpl.h b/cscore/src/main/native/cpp/RawSourceImpl.h
index a15278dd4e..bb9a49fc67 100644
--- a/cscore/src/main/native/cpp/RawSourceImpl.h
+++ b/cscore/src/main/native/cpp/RawSourceImpl.h
@@ -9,10 +9,10 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <wpi/ArrayRef.h>
-#include <wpi/Twine.h>
 
 #include "ConfigurableSourceImpl.h"
 #include "SourceImpl.h"
@@ -22,7 +22,7 @@ namespace cs {
 
 class RawSourceImpl : public ConfigurableSourceImpl {
  public:
-  RawSourceImpl(const wpi::Twine& name, wpi::Logger& logger, Notifier& notifier,
+  RawSourceImpl(std::string_view name, wpi::Logger& logger, Notifier& notifier,
                 Telemetry& telemetry, const VideoMode& mode);
   ~RawSourceImpl() override;
 
diff --git a/cscore/src/main/native/cpp/SinkImpl.cpp b/cscore/src/main/native/cpp/SinkImpl.cpp
index a092cb7d59..93a625f814 100644
--- a/cscore/src/main/native/cpp/SinkImpl.cpp
+++ b/cscore/src/main/native/cpp/SinkImpl.cpp
@@ -12,12 +12,12 @@
 
 using namespace cs;
 
-SinkImpl::SinkImpl(const wpi::Twine& name, wpi::Logger& logger,
+SinkImpl::SinkImpl(std::string_view name, wpi::Logger& logger,
                    Notifier& notifier, Telemetry& telemetry)
     : m_logger(logger),
       m_notifier(notifier),
       m_telemetry(telemetry),
-      m_name{name.str()} {}
+      m_name{name} {}
 
 SinkImpl::~SinkImpl() {
   if (m_source) {
@@ -28,15 +28,16 @@ SinkImpl::~SinkImpl() {
   }
 }
 
-void SinkImpl::SetDescription(const wpi::Twine& description) {
+void SinkImpl::SetDescription(std::string_view description) {
   std::scoped_lock lock(m_mutex);
-  m_description = description.str();
+  m_description = description;
 }
 
-wpi::StringRef SinkImpl::GetDescription(wpi::SmallVectorImpl<char>& buf) const {
+std::string_view SinkImpl::GetDescription(
+    wpi::SmallVectorImpl<char>& buf) const {
   std::scoped_lock lock(m_mutex);
   buf.append(m_description.begin(), m_description.end());
-  return wpi::StringRef{buf.data(), buf.size()};
+  return {buf.data(), buf.size()};
 }
 
 void SinkImpl::Enable() {
@@ -106,28 +107,27 @@ std::string SinkImpl::GetError() const {
   if (!m_source) {
     return "no source connected";
   }
-  return m_source->GetCurFrame().GetError();
+  return std::string{m_source->GetCurFrame().GetError()};
 }
 
-wpi::StringRef SinkImpl::GetError(wpi::SmallVectorImpl<char>& buf) const {
+std::string_view SinkImpl::GetError(wpi::SmallVectorImpl<char>& buf) const {
   std::scoped_lock lock(m_mutex);
   if (!m_source) {
     return "no source connected";
   }
   // Make a copy as it's shared data
-  wpi::StringRef error = m_source->GetCurFrame().GetError();
+  std::string_view error = m_source->GetCurFrame().GetError();
   buf.clear();
   buf.append(error.data(), error.data() + error.size());
-  return wpi::StringRef{buf.data(), buf.size()};
+  return {buf.data(), buf.size()};
 }
 
-bool SinkImpl::SetConfigJson(wpi::StringRef config, CS_Status* status) {
+bool SinkImpl::SetConfigJson(std::string_view config, CS_Status* status) {
   wpi::json j;
   try {
     j = wpi::json::parse(config);
   } catch (const wpi::json::parse_error& e) {
-    SWARNING("SetConfigJson: parse error at byte " << e.byte << ": "
-                                                   << e.what());
+    SWARNING("SetConfigJson: parse error at byte {}: {}", e.byte, e.what());
     *status = CS_PROPERTY_WRITE_FAILED;
     return false;
   }
@@ -169,12 +169,12 @@ void SinkImpl::NotifyPropertyCreated(int propIndex, PropertyImpl& prop) {
   if (prop.propKind == CS_PROP_ENUM) {
     m_notifier.NotifySinkProperty(*this, CS_SINK_PROPERTY_CHOICES_UPDATED,
                                   prop.name, propIndex, prop.propKind,
-                                  prop.value, wpi::Twine{});
+                                  prop.value, {});
   }
 }
 
 void SinkImpl::UpdatePropertyValue(int property, bool setString, int value,
-                                   const wpi::Twine& valueStr) {
+                                   std::string_view valueStr) {
   auto prop = GetProperty(property);
   if (!prop) {
     return;
diff --git a/cscore/src/main/native/cpp/SinkImpl.h b/cscore/src/main/native/cpp/SinkImpl.h
index 5c8faa42e7..aa37d61230 100644
--- a/cscore/src/main/native/cpp/SinkImpl.h
+++ b/cscore/src/main/native/cpp/SinkImpl.h
@@ -7,10 +7,9 @@
 
 #include <memory>
 #include <string>
+#include <string_view>
 
 #include <wpi/Logger.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 #include <wpi/mutex.h>
 
 #include "SourceImpl.h"
@@ -27,16 +26,16 @@ class Telemetry;
 
 class SinkImpl : public PropertyContainer {
  public:
-  explicit SinkImpl(const wpi::Twine& name, wpi::Logger& logger,
+  explicit SinkImpl(std::string_view name, wpi::Logger& logger,
                     Notifier& notifier, Telemetry& telemetry);
   ~SinkImpl() override;
   SinkImpl(const SinkImpl& queue) = delete;
   SinkImpl& operator=(const SinkImpl& queue) = delete;
 
-  wpi::StringRef GetName() const { return m_name; }
+  std::string_view GetName() const { return m_name; }
 
-  void SetDescription(const wpi::Twine& description);
-  wpi::StringRef GetDescription(wpi::SmallVectorImpl<char>& buf) const;
+  void SetDescription(std::string_view description);
+  std::string_view GetDescription(wpi::SmallVectorImpl<char>& buf) const;
 
   void Enable();
   void Disable();
@@ -50,9 +49,9 @@ class SinkImpl : public PropertyContainer {
   }
 
   std::string GetError() const;
-  wpi::StringRef GetError(wpi::SmallVectorImpl<char>& buf) const;
+  std::string_view GetError(wpi::SmallVectorImpl<char>& buf) const;
 
-  bool SetConfigJson(wpi::StringRef config, CS_Status* status);
+  bool SetConfigJson(std::string_view config, CS_Status* status);
   virtual bool SetConfigJson(const wpi::json& config, CS_Status* status);
   std::string GetConfigJson(CS_Status* status);
   virtual wpi::json GetConfigJsonObject(CS_Status* status);
@@ -61,7 +60,7 @@ class SinkImpl : public PropertyContainer {
   // PropertyContainer implementation
   void NotifyPropertyCreated(int propIndex, PropertyImpl& prop) override;
   void UpdatePropertyValue(int property, bool setString, int value,
-                           const wpi::Twine& valueStr) override;
+                           std::string_view valueStr) override;
 
   virtual void SetSourceImpl(std::shared_ptr<SourceImpl> source);
 
diff --git a/cscore/src/main/native/cpp/SourceImpl.cpp b/cscore/src/main/native/cpp/SourceImpl.cpp
index b88a1e1a2a..da5aa1d9f5 100644
--- a/cscore/src/main/native/cpp/SourceImpl.cpp
+++ b/cscore/src/main/native/cpp/SourceImpl.cpp
@@ -8,6 +8,7 @@
 #include <cstring>
 #include <memory>
 
+#include <wpi/StringExtras.h>
 #include <wpi/json.h>
 #include <wpi/timestamp.h>
 
@@ -19,13 +20,13 @@ using namespace cs;
 
 static constexpr size_t kMaxImagesAvail = 32;
 
-SourceImpl::SourceImpl(const wpi::Twine& name, wpi::Logger& logger,
+SourceImpl::SourceImpl(std::string_view name, wpi::Logger& logger,
                        Notifier& notifier, Telemetry& telemetry)
     : m_logger(logger),
       m_notifier(notifier),
       m_telemetry(telemetry),
-      m_name{name.str()} {
-  m_frame = Frame{*this, wpi::StringRef{}, 0};
+      m_name{name} {
+  m_frame = Frame{*this, std::string_view{}, 0};
 }
 
 SourceImpl::~SourceImpl() {
@@ -41,16 +42,16 @@ SourceImpl::~SourceImpl() {
   // Everything else can clean up itself.
 }
 
-void SourceImpl::SetDescription(const wpi::Twine& description) {
+void SourceImpl::SetDescription(std::string_view description) {
   std::scoped_lock lock(m_mutex);
-  m_description = description.str();
+  m_description = description;
 }
 
-wpi::StringRef SourceImpl::GetDescription(
+std::string_view SourceImpl::GetDescription(
     wpi::SmallVectorImpl<char>& buf) const {
   std::scoped_lock lock(m_mutex);
   buf.append(m_description.begin(), m_description.end());
-  return wpi::StringRef{buf.data(), buf.size()};
+  return {buf.data(), buf.size()};
 }
 
 void SourceImpl::SetConnected(bool connected) {
@@ -93,7 +94,7 @@ Frame SourceImpl::GetNextFrame(double timeout) {
 void SourceImpl::Wakeup() {
   {
     std::scoped_lock lock{m_frameMutex};
-    m_frame = Frame{*this, wpi::StringRef{}, 0};
+    m_frame = Frame{*this, std::string_view{}, 0};
   }
   m_frameCv.notify_all();
 }
@@ -168,13 +169,12 @@ bool SourceImpl::SetFPS(int fps, CS_Status* status) {
   return SetVideoMode(mode, status);
 }
 
-bool SourceImpl::SetConfigJson(wpi::StringRef config, CS_Status* status) {
+bool SourceImpl::SetConfigJson(std::string_view config, CS_Status* status) {
   wpi::json j;
   try {
     j = wpi::json::parse(config);
   } catch (const wpi::json::parse_error& e) {
-    SWARNING("SetConfigJson: parse error at byte " << e.byte << ": "
-                                                   << e.what());
+    SWARNING("SetConfigJson: parse error at byte {}: {}", e.byte, e.what());
     *status = CS_PROPERTY_WRITE_FAILED;
     return false;
   }
@@ -188,23 +188,22 @@ bool SourceImpl::SetConfigJson(const wpi::json& config, CS_Status* status) {
   if (config.count("pixel format") != 0) {
     try {
       auto str = config.at("pixel format").get<std::string>();
-      wpi::StringRef s(str);
-      if (s.equals_lower("mjpeg")) {
+      if (wpi::equals_lower(str, "mjpeg")) {
         mode.pixelFormat = cs::VideoMode::kMJPEG;
-      } else if (s.equals_lower("yuyv")) {
+      } else if (wpi::equals_lower(str, "yuyv")) {
         mode.pixelFormat = cs::VideoMode::kYUYV;
-      } else if (s.equals_lower("rgb565")) {
+      } else if (wpi::equals_lower(str, "rgb565")) {
         mode.pixelFormat = cs::VideoMode::kRGB565;
-      } else if (s.equals_lower("bgr")) {
+      } else if (wpi::equals_lower(str, "bgr")) {
         mode.pixelFormat = cs::VideoMode::kBGR;
-      } else if (s.equals_lower("gray")) {
+      } else if (wpi::equals_lower(str, "gray")) {
         mode.pixelFormat = cs::VideoMode::kGray;
       } else {
-        SWARNING("SetConfigJson: could not understand pixel format value '"
-                 << str << '\'');
+        SWARNING("SetConfigJson: could not understand pixel format value '{}'",
+                 str);
       }
     } catch (const wpi::json::exception& e) {
-      SWARNING("SetConfigJson: could not read pixel format: " << e.what());
+      SWARNING("SetConfigJson: could not read pixel format: {}", e.what());
     }
   }
 
@@ -213,7 +212,7 @@ bool SourceImpl::SetConfigJson(const wpi::json& config, CS_Status* status) {
     try {
       mode.width = config.at("width").get<unsigned int>();
     } catch (const wpi::json::exception& e) {
-      SWARNING("SetConfigJson: could not read width: " << e.what());
+      SWARNING("SetConfigJson: could not read width: {}", e.what());
     }
   }
 
@@ -222,7 +221,7 @@ bool SourceImpl::SetConfigJson(const wpi::json& config, CS_Status* status) {
     try {
       mode.height = config.at("height").get<unsigned int>();
     } catch (const wpi::json::exception& e) {
-      SWARNING("SetConfigJson: could not read height: " << e.what());
+      SWARNING("SetConfigJson: could not read height: {}", e.what());
     }
   }
 
@@ -231,30 +230,31 @@ bool SourceImpl::SetConfigJson(const wpi::json& config, CS_Status* status) {
     try {
       mode.fps = config.at("fps").get<unsigned int>();
     } catch (const wpi::json::exception& e) {
-      SWARNING("SetConfigJson: could not read fps: " << e.what());
+      SWARNING("SetConfigJson: could not read fps: {}", e.what());
     }
   }
 
   // if all of video mode is set, use SetVideoMode, otherwise piecemeal it
   if (mode.pixelFormat != VideoMode::kUnknown && mode.width != 0 &&
       mode.height != 0 && mode.fps != 0) {
-    SINFO("SetConfigJson: setting video mode to pixelFormat "
-          << mode.pixelFormat << ", width " << mode.width << ", height "
-          << mode.height << ", fps " << mode.fps);
+    SINFO(
+        "SetConfigJson: setting video mode to pixelFormat {}, width {}, height "
+        "{}, fps {}",
+        mode.pixelFormat, mode.width, mode.height, mode.fps);
     SetVideoMode(mode, status);
   } else {
     if (mode.pixelFormat != cs::VideoMode::kUnknown) {
-      SINFO("SetConfigJson: setting pixelFormat " << mode.pixelFormat);
+      SINFO("SetConfigJson: setting pixelFormat {}", mode.pixelFormat);
       SetPixelFormat(static_cast<cs::VideoMode::PixelFormat>(mode.pixelFormat),
                      status);
     }
     if (mode.width != 0 && mode.height != 0) {
-      SINFO("SetConfigJson: setting width " << mode.width << ", height "
-                                            << mode.height);
+      SINFO("SetConfigJson: setting width {}, height {}", mode.width,
+            mode.height);
       SetResolution(mode.width, mode.height, status);
     }
     if (mode.fps != 0) {
-      SINFO("SetConfigJson: setting fps " << mode.fps);
+      SINFO("SetConfigJson: setting fps {}", mode.fps);
       SetFPS(mode.fps, status);
     }
   }
@@ -263,10 +263,10 @@ bool SourceImpl::SetConfigJson(const wpi::json& config, CS_Status* status) {
   if (config.count("brightness") != 0) {
     try {
       int val = config.at("brightness").get<int>();
-      SINFO("SetConfigJson: setting brightness to " << val);
+      SINFO("SetConfigJson: setting brightness to {}", val);
       SetBrightness(val, status);
     } catch (const wpi::json::exception& e) {
-      SWARNING("SetConfigJson: could not read brightness: " << e.what());
+      SWARNING("SetConfigJson: could not read brightness: {}", e.what());
     }
   }
 
@@ -276,24 +276,24 @@ bool SourceImpl::SetConfigJson(const wpi::json& config, CS_Status* status) {
       auto& setting = config.at("white balance");
       if (setting.is_string()) {
         auto str = setting.get<std::string>();
-        wpi::StringRef s(str);
-        if (s.equals_lower("auto")) {
-          SINFO("SetConfigJson: setting white balance to auto");
+        if (wpi::equals_lower(str, "auto")) {
+          SINFO("SetConfigJson: setting white balance to {}", "auto");
           SetWhiteBalanceAuto(status);
-        } else if (s.equals_lower("hold")) {
-          SINFO("SetConfigJson: setting white balance to hold current");
+        } else if (wpi::equals_lower(str, "hold")) {
+          SINFO("SetConfigJson: setting white balance to {}", "hold current");
           SetWhiteBalanceHoldCurrent(status);
         } else {
-          SWARNING("SetConfigJson: could not understand white balance value '"
-                   << str << '\'');
+          SWARNING(
+              "SetConfigJson: could not understand white balance value '{}'",
+              str);
         }
       } else {
         int val = setting.get<int>();
-        SINFO("SetConfigJson: setting white balance to " << val);
+        SINFO("SetConfigJson: setting white balance to {}", val);
         SetWhiteBalanceManual(val, status);
       }
     } catch (const wpi::json::exception& e) {
-      SWARNING("SetConfigJson: could not read white balance: " << e.what());
+      SWARNING("SetConfigJson: could not read white balance: {}", e.what());
     }
   }
 
@@ -303,24 +303,23 @@ bool SourceImpl::SetConfigJson(const wpi::json& config, CS_Status* status) {
       auto& setting = config.at("exposure");
       if (setting.is_string()) {
         auto str = setting.get<std::string>();
-        wpi::StringRef s(str);
-        if (s.equals_lower("auto")) {
-          SINFO("SetConfigJson: setting exposure to auto");
+        if (wpi::equals_lower(str, "auto")) {
+          SINFO("SetConfigJson: setting exposure to {}", "auto");
           SetExposureAuto(status);
-        } else if (s.equals_lower("hold")) {
-          SINFO("SetConfigJson: setting exposure to hold current");
+        } else if (wpi::equals_lower(str, "hold")) {
+          SINFO("SetConfigJson: setting exposure to {}", "hold current");
           SetExposureHoldCurrent(status);
         } else {
-          SWARNING("SetConfigJson: could not understand exposure value '"
-                   << str << '\'');
+          SWARNING("SetConfigJson: could not understand exposure value '{}'",
+                   str);
         }
       } else {
         int val = setting.get<int>();
-        SINFO("SetConfigJson: setting exposure to " << val);
+        SINFO("SetConfigJson: setting exposure to {}", val);
         SetExposureManual(val, status);
       }
     } catch (const wpi::json::exception& e) {
-      SWARNING("SetConfigJson: could not read exposure: " << e.what());
+      SWARNING("SetConfigJson: could not read exposure: {}", e.what());
     }
   }
 
@@ -344,7 +343,7 @@ wpi::json SourceImpl::GetConfigJsonObject(CS_Status* status) {
   wpi::json j;
 
   // pixel format
-  wpi::StringRef pixelFormat;
+  std::string_view pixelFormat;
   switch (m_mode.pixelFormat) {
     case VideoMode::kMJPEG:
       pixelFormat = "mjpeg";
@@ -440,14 +439,12 @@ std::unique_ptr<Image> SourceImpl::AllocImage(
 }
 
 void SourceImpl::PutFrame(VideoMode::PixelFormat pixelFormat, int width,
-                          int height, wpi::StringRef data, Frame::Time time) {
+                          int height, std::string_view data, Frame::Time time) {
   auto image = AllocImage(pixelFormat, width, height, data.size());
 
   // Copy in image data
-  SDEBUG4("Copying data to "
-          << reinterpret_cast<const void*>(image->data()) << " from "
-          << reinterpret_cast<const void*>(data.data()) << " (" << data.size()
-          << " bytes)");
+  SDEBUG4("Copying data to {} from {} ({} bytes)", fmt::ptr(image->data()),
+          fmt::ptr(data.data()), data.size());
   std::memcpy(image->data(), data.data(), data.size());
 
   PutFrame(std::move(image), time);
@@ -468,7 +465,7 @@ void SourceImpl::PutFrame(std::unique_ptr<Image> image, Frame::Time time) {
   m_frameCv.notify_all();
 }
 
-void SourceImpl::PutError(const wpi::Twine& msg, Frame::Time time) {
+void SourceImpl::PutError(std::string_view msg, Frame::Time time) {
   // Update frame
   {
     std::scoped_lock lock{m_frameMutex};
@@ -487,12 +484,12 @@ void SourceImpl::NotifyPropertyCreated(int propIndex, PropertyImpl& prop) {
   if (prop.propKind == CS_PROP_ENUM) {
     m_notifier.NotifySourceProperty(*this, CS_SOURCE_PROPERTY_CHOICES_UPDATED,
                                     prop.name, propIndex, prop.propKind,
-                                    prop.value, wpi::Twine{});
+                                    prop.value, {});
   }
 }
 
 void SourceImpl::UpdatePropertyValue(int property, bool setString, int value,
-                                     const wpi::Twine& valueStr) {
+                                     std::string_view valueStr) {
   auto prop = GetProperty(property);
   if (!prop) {
     return;
diff --git a/cscore/src/main/native/cpp/SourceImpl.h b/cscore/src/main/native/cpp/SourceImpl.h
index 9b7fae4175..0a7839e23a 100644
--- a/cscore/src/main/native/cpp/SourceImpl.h
+++ b/cscore/src/main/native/cpp/SourceImpl.h
@@ -9,12 +9,11 @@
 #include <cstddef>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <wpi/ArrayRef.h>
 #include <wpi/Logger.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 #include <wpi/condition_variable.h>
 #include <wpi/mutex.h>
 
@@ -37,7 +36,7 @@ class SourceImpl : public PropertyContainer {
   friend class Frame;
 
  public:
-  SourceImpl(const wpi::Twine& name, wpi::Logger& logger, Notifier& notifier,
+  SourceImpl(std::string_view name, wpi::Logger& logger, Notifier& notifier,
              Telemetry& telemetry);
   ~SourceImpl() override;
   SourceImpl(const SourceImpl& oth) = delete;
@@ -45,10 +44,10 @@ class SourceImpl : public PropertyContainer {
 
   virtual void Start() = 0;
 
-  wpi::StringRef GetName() const { return m_name; }
+  std::string_view GetName() const { return m_name; }
 
-  void SetDescription(const wpi::Twine& description);
-  wpi::StringRef GetDescription(wpi::SmallVectorImpl<char>& buf) const;
+  void SetDescription(std::string_view description);
+  std::string_view GetDescription(wpi::SmallVectorImpl<char>& buf) const;
 
   void SetConnectionStrategy(CS_ConnectionStrategy strategy) {
     m_strategy = static_cast<int>(strategy);
@@ -128,7 +127,7 @@ class SourceImpl : public PropertyContainer {
   virtual bool SetResolution(int width, int height, CS_Status* status);
   virtual bool SetFPS(int fps, CS_Status* status);
 
-  bool SetConfigJson(wpi::StringRef config, CS_Status* status);
+  bool SetConfigJson(std::string_view config, CS_Status* status);
   virtual bool SetConfigJson(const wpi::json& config, CS_Status* status);
   std::string GetConfigJson(CS_Status* status);
   virtual wpi::json GetConfigJsonObject(CS_Status* status);
@@ -141,12 +140,12 @@ class SourceImpl : public PropertyContainer {
  protected:
   void NotifyPropertyCreated(int propIndex, PropertyImpl& prop) override;
   void UpdatePropertyValue(int property, bool setString, int value,
-                           const wpi::Twine& valueStr) override;
+                           std::string_view valueStr) override;
 
   void PutFrame(VideoMode::PixelFormat pixelFormat, int width, int height,
-                wpi::StringRef data, Frame::Time time);
+                std::string_view data, Frame::Time time);
   void PutFrame(std::unique_ptr<Image> image, Frame::Time time);
-  void PutError(const wpi::Twine& msg, Frame::Time time);
+  void PutError(std::string_view msg, Frame::Time time);
 
   // Notification functions for corresponding atomics
   virtual void NumSinksChanged() = 0;
diff --git a/cscore/src/main/native/cpp/c_util.h b/cscore/src/main/native/cpp/c_util.h
index 4a474df224..904d049ef6 100644
--- a/cscore/src/main/native/cpp/c_util.h
+++ b/cscore/src/main/native/cpp/c_util.h
@@ -7,13 +7,13 @@
 
 #include <cstdlib>
 #include <cstring>
+#include <string_view>
 
 #include <wpi/MemAlloc.h>
-#include <wpi/StringRef.h>
 
 namespace cs {
 
-inline char* ConvertToC(wpi::StringRef in) {
+inline char* ConvertToC(std::string_view in) {
   char* out = static_cast<char*>(wpi::safe_malloc(in.size() + 1));
   std::memmove(out, in.data(), in.size());
   out[in.size()] = '\0';
diff --git a/cscore/src/main/native/cpp/cscore_cpp.cpp b/cscore/src/main/native/cpp/cscore_cpp.cpp
index cf35cec7c0..7d3828e318 100644
--- a/cscore/src/main/native/cpp/cscore_cpp.cpp
+++ b/cscore/src/main/native/cpp/cscore_cpp.cpp
@@ -70,12 +70,12 @@ std::string GetPropertyName(CS_Property property, CS_Status* status) {
   if (!container) {
     return {};
   }
-  return container->GetPropertyName(propertyIndex, buf, status);
+  return std::string{container->GetPropertyName(propertyIndex, buf, status)};
 }
 
-wpi::StringRef GetPropertyName(CS_Property property,
-                               wpi::SmallVectorImpl<char>& buf,
-                               CS_Status* status) {
+std::string_view GetPropertyName(CS_Property property,
+                                 wpi::SmallVectorImpl<char>& buf,
+                                 CS_Status* status) {
   int propertyIndex;
   auto container = GetPropertyContainer(property, &propertyIndex, status);
   if (!container) {
@@ -145,12 +145,12 @@ std::string GetStringProperty(CS_Property property, CS_Status* status) {
   if (!container) {
     return {};
   }
-  return container->GetStringProperty(propertyIndex, buf, status);
+  return std::string{container->GetStringProperty(propertyIndex, buf, status)};
 }
 
-wpi::StringRef GetStringProperty(CS_Property property,
-                                 wpi::SmallVectorImpl<char>& buf,
-                                 CS_Status* status) {
+std::string_view GetStringProperty(CS_Property property,
+                                   wpi::SmallVectorImpl<char>& buf,
+                                   CS_Status* status) {
   int propertyIndex;
   auto container = GetPropertyContainer(property, &propertyIndex, status);
   if (!container) {
@@ -159,7 +159,7 @@ wpi::StringRef GetStringProperty(CS_Property property,
   return container->GetStringProperty(propertyIndex, buf, status);
 }
 
-void SetStringProperty(CS_Property property, const wpi::Twine& value,
+void SetStringProperty(CS_Property property, std::string_view value,
                        CS_Status* status) {
   int propertyIndex;
   auto container = GetPropertyContainer(property, &propertyIndex, status);
@@ -196,17 +196,18 @@ std::string GetSourceName(CS_Source source, CS_Status* status) {
   auto data = Instance::GetInstance().GetSource(source);
   if (!data) {
     *status = CS_INVALID_HANDLE;
-    return std::string{};
+    return {};
   }
-  return data->source->GetName();
+  return std::string{data->source->GetName()};
 }
 
-wpi::StringRef GetSourceName(CS_Source source, wpi::SmallVectorImpl<char>& buf,
-                             CS_Status* status) {
+std::string_view GetSourceName(CS_Source source,
+                               wpi::SmallVectorImpl<char>& buf,
+                               CS_Status* status) {
   auto data = Instance::GetInstance().GetSource(source);
   if (!data) {
     *status = CS_INVALID_HANDLE;
-    return wpi::StringRef{};
+    return {};
   }
   return data->source->GetName();
 }
@@ -215,19 +216,19 @@ std::string GetSourceDescription(CS_Source source, CS_Status* status) {
   auto data = Instance::GetInstance().GetSource(source);
   if (!data) {
     *status = CS_INVALID_HANDLE;
-    return std::string{};
+    return {};
   }
   wpi::SmallString<128> buf;
-  return data->source->GetDescription(buf);
+  return std::string{data->source->GetDescription(buf)};
 }
 
-wpi::StringRef GetSourceDescription(CS_Source source,
-                                    wpi::SmallVectorImpl<char>& buf,
-                                    CS_Status* status) {
+std::string_view GetSourceDescription(CS_Source source,
+                                      wpi::SmallVectorImpl<char>& buf,
+                                      CS_Status* status) {
   auto data = Instance::GetInstance().GetSource(source);
   if (!data) {
     *status = CS_INVALID_HANDLE;
-    return wpi::StringRef{};
+    return {};
   }
   return data->source->GetDescription(buf);
 }
@@ -270,7 +271,7 @@ bool IsSourceEnabled(CS_Source source, CS_Status* status) {
   return data->source->IsEnabled();
 }
 
-CS_Property GetSourceProperty(CS_Source source, const wpi::Twine& name,
+CS_Property GetSourceProperty(CS_Source source, std::string_view name,
                               CS_Status* status) {
   auto data = Instance::GetInstance().GetSource(source);
   if (!data) {
@@ -349,7 +350,7 @@ bool SetSourceFPS(CS_Source source, int fps, CS_Status* status) {
   return data->source->SetFPS(fps, status);
 }
 
-bool SetSourceConfigJson(CS_Source source, wpi::StringRef config,
+bool SetSourceConfigJson(CS_Source source, std::string_view config,
                          CS_Status* status) {
   auto data = Instance::GetInstance().GetSource(source);
   if (!data) {
@@ -531,17 +532,17 @@ std::string GetSinkName(CS_Sink sink, CS_Status* status) {
   auto data = Instance::GetInstance().GetSink(sink);
   if (!data) {
     *status = CS_INVALID_HANDLE;
-    return std::string{};
+    return {};
   }
-  return data->sink->GetName();
+  return std::string{data->sink->GetName()};
 }
 
-wpi::StringRef GetSinkName(CS_Sink sink, wpi::SmallVectorImpl<char>& buf,
-                           CS_Status* status) {
+std::string_view GetSinkName(CS_Sink sink, wpi::SmallVectorImpl<char>& buf,
+                             CS_Status* status) {
   auto data = Instance::GetInstance().GetSink(sink);
   if (!data) {
     *status = CS_INVALID_HANDLE;
-    return wpi::StringRef{};
+    return {};
   }
   return data->sink->GetName();
 }
@@ -550,23 +551,24 @@ std::string GetSinkDescription(CS_Sink sink, CS_Status* status) {
   auto data = Instance::GetInstance().GetSink(sink);
   if (!data) {
     *status = CS_INVALID_HANDLE;
-    return std::string{};
+    return {};
   }
   wpi::SmallString<128> buf;
-  return data->sink->GetDescription(buf);
+  return std::string{data->sink->GetDescription(buf)};
 }
 
-wpi::StringRef GetSinkDescription(CS_Sink sink, wpi::SmallVectorImpl<char>& buf,
-                                  CS_Status* status) {
+std::string_view GetSinkDescription(CS_Sink sink,
+                                    wpi::SmallVectorImpl<char>& buf,
+                                    CS_Status* status) {
   auto data = Instance::GetInstance().GetSink(sink);
   if (!data) {
     *status = CS_INVALID_HANDLE;
-    return wpi::StringRef{};
+    return {};
   }
   return data->sink->GetDescription(buf);
 }
 
-CS_Property GetSinkProperty(CS_Sink sink, const wpi::Twine& name,
+CS_Property GetSinkProperty(CS_Sink sink, std::string_view name,
                             CS_Status* status) {
   auto data = Instance::GetInstance().GetSink(sink);
   if (!data) {
@@ -596,7 +598,8 @@ wpi::ArrayRef<CS_Property> EnumerateSinkProperties(
   return vec;
 }
 
-bool SetSinkConfigJson(CS_Sink sink, wpi::StringRef config, CS_Status* status) {
+bool SetSinkConfigJson(CS_Sink sink, std::string_view config,
+                       CS_Status* status) {
   auto data = Instance::GetInstance().GetSink(sink);
   if (!data) {
     *status = CS_INVALID_HANDLE;
@@ -663,7 +666,7 @@ CS_Source GetSinkSource(CS_Sink sink, CS_Status* status) {
   return data->sourceHandle.load();
 }
 
-CS_Property GetSinkSourceProperty(CS_Sink sink, const wpi::Twine& name,
+CS_Property GetSinkSourceProperty(CS_Sink sink, std::string_view name,
                                   CS_Status* status) {
   auto data = Instance::GetInstance().GetSink(sink);
   if (!data) {
diff --git a/cscore/src/main/native/cpp/cscore_oo.cpp b/cscore/src/main/native/cpp/cscore_oo.cpp
index 86e549074f..cca5ba73dd 100644
--- a/cscore/src/main/native/cpp/cscore_oo.cpp
+++ b/cscore/src/main/native/cpp/cscore_oo.cpp
@@ -4,6 +4,7 @@
 
 #include "cscore_oo.h"
 
+#include <fmt/format.h>
 #include <wpi/json.h>
 
 using namespace cs;
@@ -82,3 +83,7 @@ std::vector<VideoSink> VideoSink::EnumerateSinks() {
   }
   return sinks;
 }
+
+std::string AxisCamera::HostToUrl(std::string_view host) {
+  return fmt::format("http://{}/mjpg/video.mjpg", host);
+}
diff --git a/cscore/src/main/native/cpp/jni/CameraServerJNI.cpp b/cscore/src/main/native/cpp/jni/CameraServerJNI.cpp
index a603fbf820..afdf566787 100644
--- a/cscore/src/main/native/cpp/jni/CameraServerJNI.cpp
+++ b/cscore/src/main/native/cpp/jni/CameraServerJNI.cpp
@@ -4,10 +4,10 @@
 
 #include <exception>
 
+#include <fmt/format.h>
 #include <opencv2/core/core.hpp>
 #include <wpi/SmallString.h>
 #include <wpi/jni_util.h>
-#include <wpi/raw_ostream.h>
 
 #include "cscore_cpp.h"
 #include "cscore_cv.h"
@@ -197,7 +197,8 @@ static void ReportError(JNIEnv* env, CS_Status status) {
   if (status == CS_OK) {
     return;
   }
-  wpi::SmallString<64> msg;
+  std::string_view msg;
+  std::string msgBuf;
   switch (status) {
     case CS_PROPERTY_WRITE_FAILED:
       msg = "property write failed";
@@ -230,8 +231,8 @@ static void ReportError(JNIEnv* env, CS_Status status) {
       msg = "telemetry not enabled";
       break;
     default: {
-      wpi::raw_svector_ostream oss{msg};
-      oss << "unknown error code=" << status;
+      msgBuf = fmt::format("unknown error code={}", status);
+      msg = msgBuf;
       break;
     }
   }
@@ -577,7 +578,7 @@ Java_edu_wpi_first_cscore_CameraServerJNI_createHttpCameraMulti
       // TODO
       return 0;
     }
-    vec.push_back(JStringRef{env, elem}.str());
+    vec.emplace_back(JStringRef{env, elem}.str());
   }
   CS_Status status = 0;
   auto val =
@@ -1172,7 +1173,7 @@ Java_edu_wpi_first_cscore_CameraServerJNI_setHttpCameraUrls
       // TODO
       return;
     }
-    vec.push_back(JStringRef{env, elem}.str());
+    vec.emplace_back(JStringRef{env, elem}.str());
   }
   CS_Status status = 0;
   cs::SetHttpCameraUrls(source, vec, &status);
@@ -1353,7 +1354,7 @@ Java_edu_wpi_first_cscore_CameraServerJNI_setSourceEnumPropertyChoices
       // TODO
       return;
     }
-    vec.push_back(JStringRef{env, elem}.str());
+    vec.emplace_back(JStringRef{env, elem}.str());
   }
   CS_Status status = 0;
   cs::SetSourceEnumPropertyChoices(source, property, vec, &status);
diff --git a/cscore/src/main/native/include/cscore_cpp.h b/cscore/src/main/native/include/cscore_cpp.h
index 52f6f5f93c..593ad08936 100644
--- a/cscore/src/main/native/include/cscore_cpp.h
+++ b/cscore/src/main/native/include/cscore_cpp.h
@@ -9,12 +9,11 @@
 
 #include <functional>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <wpi/ArrayRef.h>
 #include <wpi/SmallVector.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 
 #include "cscore_c.h"
 
@@ -122,8 +121,8 @@ struct RawEvent {
 
   RawEvent() = default;
   explicit RawEvent(RawEvent::Kind kind_) : kind{kind_} {}
-  RawEvent(const wpi::Twine& name_, CS_Handle handle_, RawEvent::Kind kind_)
-      : kind{kind_}, name{name_.str()} {
+  RawEvent(std::string_view name_, CS_Handle handle_, RawEvent::Kind kind_)
+      : kind{kind_}, name{name_} {
     if (kind_ == kSinkCreated || kind_ == kSinkDestroyed ||
         kind_ == kSinkEnabled || kind_ == kSinkDisabled) {
       sinkHandle = handle_;
@@ -131,21 +130,21 @@ struct RawEvent {
       sourceHandle = handle_;
     }
   }
-  RawEvent(const wpi::Twine& name_, CS_Source source_, const VideoMode& mode_)
+  RawEvent(std::string_view name_, CS_Source source_, const VideoMode& mode_)
       : kind{kSourceVideoModeChanged},
         sourceHandle{source_},
-        name{name_.str()},
+        name{name_},
         mode{mode_} {}
-  RawEvent(const wpi::Twine& name_, CS_Source source_, RawEvent::Kind kind_,
+  RawEvent(std::string_view name_, CS_Source source_, RawEvent::Kind kind_,
            CS_Property property_, CS_PropertyKind propertyKind_, int value_,
-           const wpi::Twine& valueStr_)
+           std::string_view valueStr_)
       : kind{kind_},
         sourceHandle{source_},
-        name{name_.str()},
+        name{name_},
         propertyHandle{property_},
         propertyKind{propertyKind_},
         value{value_},
-        valueStr{valueStr_.str()} {}
+        valueStr{valueStr_} {}
 
   Kind kind;
 
@@ -175,9 +174,9 @@ struct RawEvent {
  */
 CS_PropertyKind GetPropertyKind(CS_Property property, CS_Status* status);
 std::string GetPropertyName(CS_Property property, CS_Status* status);
-wpi::StringRef GetPropertyName(CS_Property property,
-                               wpi::SmallVectorImpl<char>& buf,
-                               CS_Status* status);
+std::string_view GetPropertyName(CS_Property property,
+                                 wpi::SmallVectorImpl<char>& buf,
+                                 CS_Status* status);
 int GetProperty(CS_Property property, CS_Status* status);
 void SetProperty(CS_Property property, int value, CS_Status* status);
 int GetPropertyMin(CS_Property property, CS_Status* status);
@@ -185,10 +184,10 @@ int GetPropertyMax(CS_Property property, CS_Status* status);
 int GetPropertyStep(CS_Property property, CS_Status* status);
 int GetPropertyDefault(CS_Property property, CS_Status* status);
 std::string GetStringProperty(CS_Property property, CS_Status* status);
-wpi::StringRef GetStringProperty(CS_Property property,
-                                 wpi::SmallVectorImpl<char>& buf,
-                                 CS_Status* status);
-void SetStringProperty(CS_Property property, const wpi::Twine& value,
+std::string_view GetStringProperty(CS_Property property,
+                                   wpi::SmallVectorImpl<char>& buf,
+                                   CS_Status* status);
+void SetStringProperty(CS_Property property, std::string_view value,
                        CS_Status* status);
 std::vector<std::string> GetEnumPropertyChoices(CS_Property property,
                                                 CS_Status* status);
@@ -198,16 +197,15 @@ std::vector<std::string> GetEnumPropertyChoices(CS_Property property,
  * @defgroup cscore_source_create_func Source Creation Functions
  * @{
  */
-CS_Source CreateUsbCameraDev(const wpi::Twine& name, int dev,
-                             CS_Status* status);
-CS_Source CreateUsbCameraPath(const wpi::Twine& name, const wpi::Twine& path,
+CS_Source CreateUsbCameraDev(std::string_view name, int dev, CS_Status* status);
+CS_Source CreateUsbCameraPath(std::string_view name, std::string_view path,
                               CS_Status* status);
-CS_Source CreateHttpCamera(const wpi::Twine& name, const wpi::Twine& url,
+CS_Source CreateHttpCamera(std::string_view name, std::string_view url,
                            CS_HttpCameraKind kind, CS_Status* status);
-CS_Source CreateHttpCamera(const wpi::Twine& name,
+CS_Source CreateHttpCamera(std::string_view name,
                            wpi::ArrayRef<std::string> urls,
                            CS_HttpCameraKind kind, CS_Status* status);
-CS_Source CreateCvSource(const wpi::Twine& name, const VideoMode& mode,
+CS_Source CreateCvSource(std::string_view name, const VideoMode& mode,
                          CS_Status* status);
 /** @} */
 
@@ -217,19 +215,20 @@ CS_Source CreateCvSource(const wpi::Twine& name, const VideoMode& mode,
  */
 CS_SourceKind GetSourceKind(CS_Source source, CS_Status* status);
 std::string GetSourceName(CS_Source source, CS_Status* status);
-wpi::StringRef GetSourceName(CS_Source source, wpi::SmallVectorImpl<char>& buf,
-                             CS_Status* status);
+std::string_view GetSourceName(CS_Source source,
+                               wpi::SmallVectorImpl<char>& buf,
+                               CS_Status* status);
 std::string GetSourceDescription(CS_Source source, CS_Status* status);
-wpi::StringRef GetSourceDescription(CS_Source source,
-                                    wpi::SmallVectorImpl<char>& buf,
-                                    CS_Status* status);
+std::string_view GetSourceDescription(CS_Source source,
+                                      wpi::SmallVectorImpl<char>& buf,
+                                      CS_Status* status);
 uint64_t GetSourceLastFrameTime(CS_Source source, CS_Status* status);
 void SetSourceConnectionStrategy(CS_Source source,
                                  CS_ConnectionStrategy strategy,
                                  CS_Status* status);
 bool IsSourceConnected(CS_Source source, CS_Status* status);
 bool IsSourceEnabled(CS_Source source, CS_Status* status);
-CS_Property GetSourceProperty(CS_Source source, const wpi::Twine& name,
+CS_Property GetSourceProperty(CS_Source source, std::string_view name,
                               CS_Status* status);
 wpi::ArrayRef<CS_Property> EnumerateSourceProperties(
     CS_Source source, wpi::SmallVectorImpl<CS_Property>& vec,
@@ -242,7 +241,7 @@ bool SetSourcePixelFormat(CS_Source source, VideoMode::PixelFormat pixelFormat,
 bool SetSourceResolution(CS_Source source, int width, int height,
                          CS_Status* status);
 bool SetSourceFPS(CS_Source source, int fps, CS_Status* status);
-bool SetSourceConfigJson(CS_Source source, wpi::StringRef config,
+bool SetSourceConfigJson(CS_Source source, std::string_view config,
                          CS_Status* status);
 bool SetSourceConfigJson(CS_Source source, const wpi::json& config,
                          CS_Status* status);
@@ -276,7 +275,7 @@ void SetCameraExposureManual(CS_Source source, int value, CS_Status* status);
  * @defgroup cscore_usbcamera_func UsbCamera Source Functions
  * @{
  */
-void SetUsbCameraPath(CS_Source, const wpi::Twine& path, CS_Status* status);
+void SetUsbCameraPath(CS_Source, std::string_view path, CS_Status* status);
 std::string GetUsbCameraPath(CS_Source source, CS_Status* status);
 UsbCameraInfo GetUsbCameraInfo(CS_Source source, CS_Status* status);
 /** @} */
@@ -295,12 +294,12 @@ std::vector<std::string> GetHttpCameraUrls(CS_Source source, CS_Status* status);
  * @defgroup cscore_opencv_source_func OpenCV Source Functions
  * @{
  */
-void NotifySourceError(CS_Source source, const wpi::Twine& msg,
+void NotifySourceError(CS_Source source, std::string_view msg,
                        CS_Status* status);
 void SetSourceConnected(CS_Source source, bool connected, CS_Status* status);
-void SetSourceDescription(CS_Source source, const wpi::Twine& description,
+void SetSourceDescription(CS_Source source, std::string_view description,
                           CS_Status* status);
-CS_Property CreateSourceProperty(CS_Source source, const wpi::Twine& name,
+CS_Property CreateSourceProperty(CS_Source source, std::string_view name,
                                  CS_PropertyKind kind, int minimum, int maximum,
                                  int step, int defaultValue, int value,
                                  CS_Status* status);
@@ -313,11 +312,10 @@ void SetSourceEnumPropertyChoices(CS_Source source, CS_Property property,
  * @defgroup cscore_sink_create_func Sink Creation Functions
  * @{
  */
-CS_Sink CreateMjpegServer(const wpi::Twine& name,
-                          const wpi::Twine& listenAddress, int port,
-                          CS_Status* status);
-CS_Sink CreateCvSink(const wpi::Twine& name, CS_Status* status);
-CS_Sink CreateCvSinkCallback(const wpi::Twine& name,
+CS_Sink CreateMjpegServer(std::string_view name, std::string_view listenAddress,
+                          int port, CS_Status* status);
+CS_Sink CreateCvSink(std::string_view name, CS_Status* status);
+CS_Sink CreateCvSinkCallback(std::string_view name,
                              std::function<void(uint64_t time)> processFrame,
                              CS_Status* status);
 
@@ -329,19 +327,21 @@ CS_Sink CreateCvSinkCallback(const wpi::Twine& name,
  */
 CS_SinkKind GetSinkKind(CS_Sink sink, CS_Status* status);
 std::string GetSinkName(CS_Sink sink, CS_Status* status);
-wpi::StringRef GetSinkName(CS_Sink sink, wpi::SmallVectorImpl<char>& buf,
-                           CS_Status* status);
+std::string_view GetSinkName(CS_Sink sink, wpi::SmallVectorImpl<char>& buf,
+                             CS_Status* status);
 std::string GetSinkDescription(CS_Sink sink, CS_Status* status);
-wpi::StringRef GetSinkDescription(CS_Sink sink, wpi::SmallVectorImpl<char>& buf,
-                                  CS_Status* status);
-CS_Property GetSinkProperty(CS_Sink sink, const wpi::Twine& name,
+std::string_view GetSinkDescription(CS_Sink sink,
+                                    wpi::SmallVectorImpl<char>& buf,
+                                    CS_Status* status);
+CS_Property GetSinkProperty(CS_Sink sink, std::string_view name,
                             CS_Status* status);
 wpi::ArrayRef<CS_Property> EnumerateSinkProperties(
     CS_Sink sink, wpi::SmallVectorImpl<CS_Property>& vec, CS_Status* status);
 void SetSinkSource(CS_Sink sink, CS_Source source, CS_Status* status);
-CS_Property GetSinkSourceProperty(CS_Sink sink, const wpi::Twine& name,
+CS_Property GetSinkSourceProperty(CS_Sink sink, std::string_view name,
                                   CS_Status* status);
-bool SetSinkConfigJson(CS_Sink sink, wpi::StringRef config, CS_Status* status);
+bool SetSinkConfigJson(CS_Sink sink, std::string_view config,
+                       CS_Status* status);
 bool SetSinkConfigJson(CS_Sink sink, const wpi::json& config,
                        CS_Status* status);
 std::string GetSinkConfigJson(CS_Sink sink, CS_Status* status);
@@ -363,11 +363,11 @@ int GetMjpegServerPort(CS_Sink sink, CS_Status* status);
  * @defgroup cscore_opencv_sink_func OpenCV Sink Functions
  * @{
  */
-void SetSinkDescription(CS_Sink sink, const wpi::Twine& description,
+void SetSinkDescription(CS_Sink sink, std::string_view description,
                         CS_Status* status);
 std::string GetSinkError(CS_Sink sink, CS_Status* status);
-wpi::StringRef GetSinkError(CS_Sink sink, wpi::SmallVectorImpl<char>& buf,
-                            CS_Status* status);
+std::string_view GetSinkError(CS_Sink sink, wpi::SmallVectorImpl<char>& buf,
+                              CS_Status* status);
 void SetSinkEnabled(CS_Sink sink, bool enabled, CS_Status* status);
 /** @} */
 
diff --git a/cscore/src/main/native/include/cscore_cv.h b/cscore/src/main/native/include/cscore_cv.h
index 45baf08739..6911ae2fa1 100644
--- a/cscore/src/main/native/include/cscore_cv.h
+++ b/cscore/src/main/native/include/cscore_cv.h
@@ -82,7 +82,7 @@ class CvSource : public ImageSource {
    * @param name Source name (arbitrary unique identifier)
    * @param mode Video mode being generated
    */
-  CvSource(const wpi::Twine& name, const VideoMode& mode);
+  CvSource(std::string_view name, const VideoMode& mode);
 
   /**
    * Create an OpenCV source.
@@ -93,8 +93,8 @@ class CvSource : public ImageSource {
    * @param height height
    * @param fps fps
    */
-  CvSource(const wpi::Twine& name, VideoMode::PixelFormat pixelFormat,
-           int width, int height, int fps);
+  CvSource(std::string_view name, VideoMode::PixelFormat pixelFormat, int width,
+           int height, int fps);
 
   /**
    * Put an OpenCV image and notify sinks.
@@ -126,7 +126,7 @@ class CvSink : public ImageSink {
    *
    * @param name Source name (arbitrary unique identifier)
    */
-  explicit CvSink(const wpi::Twine& name);
+  explicit CvSink(std::string_view name);
 
   /**
    * Create a sink for accepting OpenCV images in a separate thread.
@@ -140,7 +140,7 @@ class CvSink : public ImageSink {
    *        or GetError() as needed, but should not call (except in very
    *        unusual circumstances) WaitForImage().
    */
-  CvSink(const wpi::Twine& name,
+  CvSink(std::string_view name,
          std::function<void(uint64_t time)> processFrame);
 
   /**
@@ -165,11 +165,11 @@ class CvSink : public ImageSink {
   uint64_t GrabFrameNoTimeout(cv::Mat& image) const;
 };
 
-inline CvSource::CvSource(const wpi::Twine& name, const VideoMode& mode) {
+inline CvSource::CvSource(std::string_view name, const VideoMode& mode) {
   m_handle = CreateCvSource(name, mode, &m_status);
 }
 
-inline CvSource::CvSource(const wpi::Twine& name, VideoMode::PixelFormat format,
+inline CvSource::CvSource(std::string_view name, VideoMode::PixelFormat format,
                           int width, int height, int fps) {
   m_handle =
       CreateCvSource(name, VideoMode{format, width, height, fps}, &m_status);
@@ -180,11 +180,11 @@ inline void CvSource::PutFrame(cv::Mat& image) {
   PutSourceFrame(m_handle, image, &m_status);
 }
 
-inline CvSink::CvSink(const wpi::Twine& name) {
+inline CvSink::CvSink(std::string_view name) {
   m_handle = CreateCvSink(name, &m_status);
 }
 
-inline CvSink::CvSink(const wpi::Twine& name,
+inline CvSink::CvSink(std::string_view name,
                       std::function<void(uint64_t time)> processFrame) {
   m_handle = CreateCvSinkCallback(name, processFrame, &m_status);
 }
diff --git a/cscore/src/main/native/include/cscore_oo.h b/cscore/src/main/native/include/cscore_oo.h
index 138495d5c7..384d5230b2 100644
--- a/cscore/src/main/native/include/cscore_oo.h
+++ b/cscore/src/main/native/include/cscore_oo.h
@@ -7,6 +7,7 @@
 
 #include <initializer_list>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
@@ -71,8 +72,8 @@ class VideoProperty {
 
   // String-specific functions
   std::string GetString() const;
-  wpi::StringRef GetString(wpi::SmallVectorImpl<char>& buf) const;
-  void SetString(const wpi::Twine& value);
+  std::string_view GetString(wpi::SmallVectorImpl<char>& buf) const;
+  void SetString(std::string_view value);
 
   // Enum-specific functions
   std::vector<std::string> GetChoices() const;
@@ -194,7 +195,7 @@ class VideoSource {
    * @return Property contents (of kind Property::kNone if no property with
    *         the given name exists)
    */
-  VideoProperty GetProperty(const wpi::Twine& name);
+  VideoProperty GetProperty(std::string_view name);
 
   /**
    * Enumerate all properties of this source.
@@ -276,7 +277,7 @@ class VideoSource {
    * @param config configuration
    * @return True if set successfully
    */
-  bool SetConfigJson(wpi::StringRef config);
+  bool SetConfigJson(std::string_view config);
 
   /**
    * Set video mode and properties from a JSON configuration object.
@@ -424,7 +425,7 @@ class UsbCamera : public VideoCamera {
    * @param name Source name (arbitrary unique identifier)
    * @param dev Device number (e.g. 0 for /dev/video0)
    */
-  UsbCamera(const wpi::Twine& name, int dev);
+  UsbCamera(std::string_view name, int dev);
 
   /**
    * Create a source for a USB camera based on device path.
@@ -432,7 +433,7 @@ class UsbCamera : public VideoCamera {
    * @param name Source name (arbitrary unique identifier)
    * @param path Path to device (e.g. "/dev/video0" on Linux)
    */
-  UsbCamera(const wpi::Twine& name, const wpi::Twine& path);
+  UsbCamera(std::string_view name, std::string_view path);
 
   /**
    * Enumerate USB cameras on the local system.
@@ -444,7 +445,7 @@ class UsbCamera : public VideoCamera {
   /**
    * Change the path to the device.
    */
-  void SetPath(const wpi::Twine& path);
+  void SetPath(std::string_view path);
 
   /**
    * Get the path to the device.
@@ -483,7 +484,7 @@ class HttpCamera : public VideoCamera {
    * @param url Camera URL (e.g. "http://10.x.y.11/video/stream.mjpg")
    * @param kind Camera kind (e.g. kAxis)
    */
-  HttpCamera(const wpi::Twine& name, const wpi::Twine& url,
+  HttpCamera(std::string_view name, std::string_view url,
              HttpCameraKind kind = kUnknown);
 
   /**
@@ -493,7 +494,7 @@ class HttpCamera : public VideoCamera {
    * @param url Camera URL (e.g. "http://10.x.y.11/video/stream.mjpg")
    * @param kind Camera kind (e.g. kAxis)
    */
-  HttpCamera(const wpi::Twine& name, const char* url,
+  HttpCamera(std::string_view name, const char* url,
              HttpCameraKind kind = kUnknown);
 
   /**
@@ -503,7 +504,7 @@ class HttpCamera : public VideoCamera {
    * @param url Camera URL (e.g. "http://10.x.y.11/video/stream.mjpg")
    * @param kind Camera kind (e.g. kAxis)
    */
-  HttpCamera(const wpi::Twine& name, const std::string& url,
+  HttpCamera(std::string_view name, const std::string& url,
              HttpCameraKind kind = kUnknown);
 
   /**
@@ -513,7 +514,7 @@ class HttpCamera : public VideoCamera {
    * @param urls Array of Camera URLs
    * @param kind Camera kind (e.g. kAxis)
    */
-  HttpCamera(const wpi::Twine& name, wpi::ArrayRef<std::string> urls,
+  HttpCamera(std::string_view name, wpi::ArrayRef<std::string> urls,
              HttpCameraKind kind = kUnknown);
 
   /**
@@ -524,7 +525,7 @@ class HttpCamera : public VideoCamera {
    * @param kind Camera kind (e.g. kAxis)
    */
   template <typename T>
-  HttpCamera(const wpi::Twine& name, std::initializer_list<T> urls,
+  HttpCamera(std::string_view name, std::initializer_list<T> urls,
              HttpCameraKind kind = kUnknown);
 
   /**
@@ -556,7 +557,7 @@ class HttpCamera : public VideoCamera {
  * A source that represents an Axis IP camera.
  */
 class AxisCamera : public HttpCamera {
-  static std::string HostToUrl(const wpi::Twine& host);
+  static std::string HostToUrl(std::string_view host);
   static std::vector<std::string> HostToUrl(wpi::ArrayRef<std::string> hosts);
   template <typename T>
   static std::vector<std::string> HostToUrl(std::initializer_list<T> hosts);
@@ -569,7 +570,7 @@ class AxisCamera : public HttpCamera {
    * @param host Camera host IP or DNS name (e.g. "10.x.y.11")
    * @param kind Camera kind (e.g. kAxis)
    */
-  AxisCamera(const wpi::Twine& name, const wpi::Twine& host);
+  AxisCamera(std::string_view name, std::string_view host);
 
   /**
    * Create a source for an Axis IP camera.
@@ -578,7 +579,7 @@ class AxisCamera : public HttpCamera {
    * @param host Camera host IP or DNS name (e.g. "10.x.y.11")
    * @param kind Camera kind (e.g. kAxis)
    */
-  AxisCamera(const wpi::Twine& name, const char* host);
+  AxisCamera(std::string_view name, const char* host);
 
   /**
    * Create a source for an Axis IP camera.
@@ -587,16 +588,7 @@ class AxisCamera : public HttpCamera {
    * @param host Camera host IP or DNS name (e.g. "10.x.y.11")
    * @param kind Camera kind (e.g. kAxis)
    */
-  AxisCamera(const wpi::Twine& name, const std::string& host);
-
-  /**
-   * Create a source for an Axis IP camera.
-   *
-   * @param name Source name (arbitrary unique identifier)
-   * @param host Camera host IP or DNS name (e.g. "10.x.y.11")
-   * @param kind Camera kind (e.g. kAxis)
-   */
-  AxisCamera(const wpi::Twine& name, wpi::StringRef host);
+  AxisCamera(std::string_view name, const std::string& host);
 
   /**
    * Create a source for an Axis IP camera.
@@ -605,7 +597,7 @@ class AxisCamera : public HttpCamera {
    * @param hosts Array of Camera host IPs/DNS names
    * @param kind Camera kind (e.g. kAxis)
    */
-  AxisCamera(const wpi::Twine& name, wpi::ArrayRef<std::string> hosts);
+  AxisCamera(std::string_view name, wpi::ArrayRef<std::string> hosts);
 
   /**
    * Create a source for an Axis IP camera.
@@ -615,7 +607,7 @@ class AxisCamera : public HttpCamera {
    * @param kind Camera kind (e.g. kAxis)
    */
   template <typename T>
-  AxisCamera(const wpi::Twine& name, std::initializer_list<T> hosts);
+  AxisCamera(std::string_view name, std::initializer_list<T> hosts);
 };
 
 /**
@@ -630,7 +622,7 @@ class ImageSource : public VideoSource {
    * Signal sinks that an error has occurred.  This should be called instead
    * of NotifyFrame when an error occurs.
    */
-  void NotifyError(const wpi::Twine& msg);
+  void NotifyError(std::string_view msg);
 
   /**
    * Set source connection status.  Defaults to true.
@@ -644,7 +636,7 @@ class ImageSource : public VideoSource {
    *
    * @param description Description
    */
-  void SetDescription(const wpi::Twine& description);
+  void SetDescription(std::string_view description);
 
   /**
    * Create a property.
@@ -658,7 +650,7 @@ class ImageSource : public VideoSource {
    * @param value Current value
    * @return Property
    */
-  VideoProperty CreateProperty(const wpi::Twine& name, VideoProperty::Kind kind,
+  VideoProperty CreateProperty(std::string_view name, VideoProperty::Kind kind,
                                int minimum, int maximum, int step,
                                int defaultValue, int value);
 
@@ -673,7 +665,7 @@ class ImageSource : public VideoSource {
    * @param value Current value
    * @return Property
    */
-  VideoProperty CreateIntegerProperty(const wpi::Twine& name, int minimum,
+  VideoProperty CreateIntegerProperty(std::string_view name, int minimum,
                                       int maximum, int step, int defaultValue,
                                       int value);
 
@@ -685,7 +677,7 @@ class ImageSource : public VideoSource {
    * @param value Current value
    * @return Property
    */
-  VideoProperty CreateBooleanProperty(const wpi::Twine& name, bool defaultValue,
+  VideoProperty CreateBooleanProperty(std::string_view name, bool defaultValue,
                                       bool value);
 
   /**
@@ -696,8 +688,8 @@ class ImageSource : public VideoSource {
    * @param value Current value
    * @return Property
    */
-  VideoProperty CreateStringProperty(const wpi::Twine& name,
-                                     const wpi::Twine& value);
+  VideoProperty CreateStringProperty(std::string_view name,
+                                     std::string_view value);
 
   /**
    * Configure enum property choices.
@@ -772,7 +764,7 @@ class VideoSink {
    * @return Property (kind Property::kNone if no property with
    *         the given name exists)
    */
-  VideoProperty GetProperty(const wpi::Twine& name);
+  VideoProperty GetProperty(std::string_view name);
 
   /**
    * Enumerate all properties of this sink.
@@ -798,7 +790,7 @@ class VideoSink {
    * @param config configuration
    * @return True if set successfully
    */
-  bool SetConfigJson(wpi::StringRef config);
+  bool SetConfigJson(std::string_view config);
 
   /**
    * Set properties from a JSON configuration object.
@@ -845,7 +837,7 @@ class VideoSink {
    * @return Property (kind Property::kNone if no property with
    *         the given name exists or no source connected)
    */
-  VideoProperty GetSourceProperty(const wpi::Twine& name);
+  VideoProperty GetSourceProperty(std::string_view name);
 
   CS_Status GetLastStatus() const { return m_status; }
 
@@ -883,8 +875,7 @@ class MjpegServer : public VideoSink {
    * @param listenAddress TCP listen address (empty string for all addresses)
    * @param port TCP port number
    */
-  MjpegServer(const wpi::Twine& name, const wpi::Twine& listenAddress,
-              int port);
+  MjpegServer(std::string_view name, std::string_view listenAddress, int port);
 
   /**
    * Create a MJPEG-over-HTTP server sink.
@@ -892,7 +883,7 @@ class MjpegServer : public VideoSink {
    * @param name Sink name (arbitrary unique identifier)
    * @param port TCP port number
    */
-  MjpegServer(const wpi::Twine& name, int port) : MjpegServer(name, "", port) {}
+  MjpegServer(std::string_view name, int port) : MjpegServer(name, "", port) {}
 
   /**
    * Get the listen address of the server.
@@ -963,7 +954,7 @@ class ImageSink : public VideoSink {
    *
    * @param description Description
    */
-  void SetDescription(const wpi::Twine& description);
+  void SetDescription(std::string_view description);
 
   /**
    * Get error string.  Call this if WaitForFrame() returns 0 to determine
diff --git a/cscore/src/main/native/include/cscore_oo.inc b/cscore/src/main/native/include/cscore_oo.inc
index 887bd74522..878462afdb 100644
--- a/cscore/src/main/native/include/cscore_oo.inc
+++ b/cscore/src/main/native/include/cscore_oo.inc
@@ -6,6 +6,7 @@
 #define CSCORE_CSCORE_OO_INC_
 
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
@@ -53,13 +54,13 @@ inline std::string VideoProperty::GetString() const {
   return GetStringProperty(m_handle, &m_status);
 }
 
-inline wpi::StringRef VideoProperty::GetString(
+inline std::string_view VideoProperty::GetString(
     wpi::SmallVectorImpl<char>& buf) const {
   m_status = 0;
   return GetStringProperty(m_handle, buf, &m_status);
 }
 
-inline void VideoProperty::SetString(const wpi::Twine& value) {
+inline void VideoProperty::SetString(std::string_view value) {
   m_status = 0;
   SetStringProperty(m_handle, value, &m_status);
 }
@@ -139,7 +140,7 @@ inline bool VideoSource::IsEnabled() const {
   return IsSourceEnabled(m_handle, &m_status);
 }
 
-inline VideoProperty VideoSource::GetProperty(const wpi::Twine& name) {
+inline VideoProperty VideoSource::GetProperty(std::string_view name) {
   m_status = 0;
   return VideoProperty{GetSourceProperty(m_handle, name, &m_status)};
 }
@@ -176,7 +177,7 @@ inline bool VideoSource::SetFPS(int fps) {
   return SetSourceFPS(m_handle, fps, &m_status);
 }
 
-inline bool VideoSource::SetConfigJson(wpi::StringRef config) {
+inline bool VideoSource::SetConfigJson(std::string_view config) {
   m_status = 0;
   return SetSourceConfigJson(m_handle, config, &m_status);
 }
@@ -248,11 +249,11 @@ inline void VideoCamera::SetExposureManual(int value) {
   SetCameraExposureManual(m_handle, value, &m_status);
 }
 
-inline UsbCamera::UsbCamera(const wpi::Twine& name, int dev) {
+inline UsbCamera::UsbCamera(std::string_view name, int dev) {
   m_handle = CreateUsbCameraDev(name, dev, &m_status);
 }
 
-inline UsbCamera::UsbCamera(const wpi::Twine& name, const wpi::Twine& path) {
+inline UsbCamera::UsbCamera(std::string_view name, std::string_view path) {
   m_handle = CreateUsbCameraPath(name, path, &m_status);
 }
 
@@ -261,7 +262,7 @@ inline std::vector<UsbCameraInfo> UsbCamera::EnumerateUsbCameras() {
   return ::cs::EnumerateUsbCameras(&status);
 }
 
-inline void UsbCamera::SetPath(const wpi::Twine& path) {
+inline void UsbCamera::SetPath(std::string_view path) {
   m_status = 0;
   return ::cs::SetUsbCameraPath(m_handle, path, &m_status);
 }
@@ -282,25 +283,25 @@ inline void UsbCamera::SetConnectVerbose(int level) {
               &m_status);
 }
 
-inline HttpCamera::HttpCamera(const wpi::Twine& name, const wpi::Twine& url,
+inline HttpCamera::HttpCamera(std::string_view name, std::string_view url,
                               HttpCameraKind kind) {
   m_handle = CreateHttpCamera(
       name, url, static_cast<CS_HttpCameraKind>(static_cast<int>(kind)),
       &m_status);
 }
 
-inline HttpCamera::HttpCamera(const wpi::Twine& name, const char* url,
+inline HttpCamera::HttpCamera(std::string_view name, const char* url,
                               HttpCameraKind kind) {
   m_handle = CreateHttpCamera(
       name, url, static_cast<CS_HttpCameraKind>(static_cast<int>(kind)),
       &m_status);
 }
 
-inline HttpCamera::HttpCamera(const wpi::Twine& name, const std::string& url,
+inline HttpCamera::HttpCamera(std::string_view name, const std::string& url,
                               HttpCameraKind kind)
-    : HttpCamera(name, wpi::Twine{url}, kind) {}
+    : HttpCamera(name, std::string_view{url}, kind) {}
 
-inline HttpCamera::HttpCamera(const wpi::Twine& name,
+inline HttpCamera::HttpCamera(std::string_view name,
                               wpi::ArrayRef<std::string> urls,
                               HttpCameraKind kind) {
   m_handle = CreateHttpCamera(
@@ -309,7 +310,7 @@ inline HttpCamera::HttpCamera(const wpi::Twine& name,
 }
 
 template <typename T>
-inline HttpCamera::HttpCamera(const wpi::Twine& name,
+inline HttpCamera::HttpCamera(std::string_view name,
                               std::initializer_list<T> urls,
                               HttpCameraKind kind) {
   std::vector<std::string> vec;
@@ -349,16 +350,12 @@ inline std::vector<std::string> HttpCamera::GetUrls() const {
   return ::cs::GetHttpCameraUrls(m_handle, &m_status);
 }
 
-inline std::string AxisCamera::HostToUrl(const wpi::Twine& host) {
-  return ("http://" + host + "/mjpg/video.mjpg").str();
-}
-
 inline std::vector<std::string> AxisCamera::HostToUrl(
     wpi::ArrayRef<std::string> hosts) {
   std::vector<std::string> rv;
   rv.reserve(hosts.size());
   for (const auto& host : hosts) {
-    rv.emplace_back(HostToUrl(wpi::StringRef{host}));
+    rv.emplace_back(HostToUrl(std::string_view{host}));
   }
   return rv;
 }
@@ -369,33 +366,30 @@ inline std::vector<std::string> AxisCamera::HostToUrl(
   std::vector<std::string> rv;
   rv.reserve(hosts.size());
   for (const auto& host : hosts) {
-    rv.emplace_back(HostToUrl(wpi::StringRef{host}));
+    rv.emplace_back(HostToUrl(std::string_view{host}));
   }
   return rv;
 }
 
-inline AxisCamera::AxisCamera(const wpi::Twine& name, const wpi::Twine& host)
+inline AxisCamera::AxisCamera(std::string_view name, std::string_view host)
     : HttpCamera(name, HostToUrl(host), kAxis) {}
 
-inline AxisCamera::AxisCamera(const wpi::Twine& name, const char* host)
+inline AxisCamera::AxisCamera(std::string_view name, const char* host)
     : HttpCamera(name, HostToUrl(host), kAxis) {}
 
-inline AxisCamera::AxisCamera(const wpi::Twine& name, const std::string& host)
-    : HttpCamera(name, HostToUrl(wpi::Twine{host}), kAxis) {}
+inline AxisCamera::AxisCamera(std::string_view name, const std::string& host)
+    : HttpCamera(name, HostToUrl(std::string_view{host}), kAxis) {}
 
-inline AxisCamera::AxisCamera(const wpi::Twine& name, wpi::StringRef host)
-    : HttpCamera(name, HostToUrl(host), kAxis) {}
-
-inline AxisCamera::AxisCamera(const wpi::Twine& name,
+inline AxisCamera::AxisCamera(std::string_view name,
                               wpi::ArrayRef<std::string> hosts)
     : HttpCamera(name, HostToUrl(hosts), kAxis) {}
 
 template <typename T>
-inline AxisCamera::AxisCamera(const wpi::Twine& name,
+inline AxisCamera::AxisCamera(std::string_view name,
                               std::initializer_list<T> hosts)
     : HttpCamera(name, HostToUrl(hosts), kAxis) {}
 
-inline void ImageSource::NotifyError(const wpi::Twine& msg) {
+inline void ImageSource::NotifyError(std::string_view msg) {
   m_status = 0;
   NotifySourceError(m_handle, msg, &m_status);
 }
@@ -405,12 +399,12 @@ inline void ImageSource::SetConnected(bool connected) {
   SetSourceConnected(m_handle, connected, &m_status);
 }
 
-inline void ImageSource::SetDescription(const wpi::Twine& description) {
+inline void ImageSource::SetDescription(std::string_view description) {
   m_status = 0;
   SetSourceDescription(m_handle, description, &m_status);
 }
 
-inline VideoProperty ImageSource::CreateProperty(const wpi::Twine& name,
+inline VideoProperty ImageSource::CreateProperty(std::string_view name,
                                                  VideoProperty::Kind kind,
                                                  int minimum, int maximum,
                                                  int step, int defaultValue,
@@ -421,7 +415,7 @@ inline VideoProperty ImageSource::CreateProperty(const wpi::Twine& name,
       minimum, maximum, step, defaultValue, value, &m_status)};
 }
 
-inline VideoProperty ImageSource::CreateIntegerProperty(const wpi::Twine& name,
+inline VideoProperty ImageSource::CreateIntegerProperty(std::string_view name,
                                                         int minimum,
                                                         int maximum, int step,
                                                         int defaultValue,
@@ -434,7 +428,7 @@ inline VideoProperty ImageSource::CreateIntegerProperty(const wpi::Twine& name,
       minimum, maximum, step, defaultValue, value, &m_status)};
 }
 
-inline VideoProperty ImageSource::CreateBooleanProperty(const wpi::Twine& name,
+inline VideoProperty ImageSource::CreateBooleanProperty(std::string_view name,
                                                         bool defaultValue,
                                                         bool value) {
   m_status = 0;
@@ -445,8 +439,8 @@ inline VideoProperty ImageSource::CreateBooleanProperty(const wpi::Twine& name,
       0, 1, 1, defaultValue ? 1 : 0, value ? 1 : 0, &m_status)};
 }
 
-inline VideoProperty ImageSource::CreateStringProperty(
-    const wpi::Twine& name, const wpi::Twine& value) {
+inline VideoProperty ImageSource::CreateStringProperty(std::string_view name,
+                                                       std::string_view value) {
   m_status = 0;
   auto prop = VideoProperty{
       CreateSourceProperty(m_handle, name,
@@ -509,7 +503,7 @@ inline std::string VideoSink::GetDescription() const {
   return GetSinkDescription(m_handle, &m_status);
 }
 
-inline VideoProperty VideoSink::GetProperty(const wpi::Twine& name) {
+inline VideoProperty VideoSink::GetProperty(std::string_view name) {
   m_status = 0;
   return VideoProperty{GetSinkProperty(m_handle, name, &m_status)};
 }
@@ -529,12 +523,12 @@ inline VideoSource VideoSink::GetSource() const {
   return VideoSource{handle == 0 ? 0 : CopySource(handle, &m_status)};
 }
 
-inline VideoProperty VideoSink::GetSourceProperty(const wpi::Twine& name) {
+inline VideoProperty VideoSink::GetSourceProperty(std::string_view name) {
   m_status = 0;
   return VideoProperty{GetSinkSourceProperty(m_handle, name, &m_status)};
 }
 
-inline bool VideoSink::SetConfigJson(wpi::StringRef config) {
+inline bool VideoSink::SetConfigJson(std::string_view config) {
   m_status = 0;
   return SetSinkConfigJson(m_handle, config, &m_status);
 }
@@ -549,8 +543,8 @@ inline std::string VideoSink::GetConfigJson() const {
   return GetSinkConfigJson(m_handle, &m_status);
 }
 
-inline MjpegServer::MjpegServer(const wpi::Twine& name,
-                                const wpi::Twine& listenAddress, int port) {
+inline MjpegServer::MjpegServer(std::string_view name,
+                                std::string_view listenAddress, int port) {
   m_handle = CreateMjpegServer(name, listenAddress, port, &m_status);
 }
 
@@ -588,7 +582,7 @@ inline void MjpegServer::SetDefaultCompression(int quality) {
               quality, &m_status);
 }
 
-inline void ImageSink::SetDescription(const wpi::Twine& description) {
+inline void ImageSink::SetDescription(std::string_view description) {
   m_status = 0;
   SetSinkDescription(m_handle, description, &m_status);
 }
diff --git a/cscore/src/main/native/include/cscore_raw.h b/cscore/src/main/native/include/cscore_raw.h
index 5fc125d4cf..b52962855c 100644
--- a/cscore/src/main/native/include/cscore_raw.h
+++ b/cscore/src/main/native/include/cscore_raw.h
@@ -78,11 +78,11 @@ struct RawFrame : public CS_RawFrame {
  * @{
  */
 
-CS_Source CreateRawSource(const wpi::Twine& name, const VideoMode& mode,
+CS_Source CreateRawSource(std::string_view name, const VideoMode& mode,
                           CS_Status* status);
 
-CS_Sink CreateRawSink(const wpi::Twine& name, CS_Status* status);
-CS_Sink CreateRawSinkCallback(const wpi::Twine& name,
+CS_Sink CreateRawSink(std::string_view name, CS_Status* status);
+CS_Sink CreateRawSinkCallback(std::string_view name,
                               std::function<void(uint64_t time)> processFrame,
                               CS_Status* status);
 
@@ -107,7 +107,7 @@ class RawSource : public ImageSource {
    * @param name Source name (arbitrary unique identifier)
    * @param mode Video mode being generated
    */
-  RawSource(const wpi::Twine& name, const VideoMode& mode);
+  RawSource(std::string_view name, const VideoMode& mode);
 
   /**
    * Create a raw frame source.
@@ -118,7 +118,7 @@ class RawSource : public ImageSource {
    * @param height height
    * @param fps fps
    */
-  RawSource(const wpi::Twine& name, VideoMode::PixelFormat pixelFormat,
+  RawSource(std::string_view name, VideoMode::PixelFormat pixelFormat,
             int width, int height, int fps);
 
  protected:
@@ -147,7 +147,7 @@ class RawSink : public ImageSink {
    *
    * @param name Source name (arbitrary unique identifier)
    */
-  explicit RawSink(const wpi::Twine& name);
+  explicit RawSink(std::string_view name);
 
   /**
    * Create a sink for accepting raws images in a separate thread.
@@ -161,7 +161,7 @@ class RawSink : public ImageSink {
    *        or GetError() as needed, but should not call (except in very
    *        unusual circumstances) WaitForImage().
    */
-  RawSink(const wpi::Twine& name,
+  RawSink(std::string_view name,
           std::function<void(uint64_t time)> processFrame);
 
  protected:
@@ -187,11 +187,11 @@ class RawSink : public ImageSink {
   uint64_t GrabFrameNoTimeout(RawFrame& image) const;
 };
 
-inline RawSource::RawSource(const wpi::Twine& name, const VideoMode& mode) {
+inline RawSource::RawSource(std::string_view name, const VideoMode& mode) {
   m_handle = CreateRawSource(name, mode, &m_status);
 }
 
-inline RawSource::RawSource(const wpi::Twine& name,
+inline RawSource::RawSource(std::string_view name,
                             VideoMode::PixelFormat format, int width,
                             int height, int fps) {
   m_handle =
@@ -203,11 +203,11 @@ inline void RawSource::PutFrame(RawFrame& image) {
   PutSourceFrame(m_handle, image, &m_status);
 }
 
-inline RawSink::RawSink(const wpi::Twine& name) {
+inline RawSink::RawSink(std::string_view name) {
   m_handle = CreateRawSink(name, &m_status);
 }
 
-inline RawSink::RawSink(const wpi::Twine& name,
+inline RawSink::RawSink(std::string_view name,
                         std::function<void(uint64_t time)> processFrame) {
   m_handle = CreateRawSinkCallback(name, processFrame, &m_status);
 }
diff --git a/cscore/src/main/native/include/cscore_raw_cv.h b/cscore/src/main/native/include/cscore_raw_cv.h
index 5a2b727e05..defd239857 100644
--- a/cscore/src/main/native/include/cscore_raw_cv.h
+++ b/cscore/src/main/native/include/cscore_raw_cv.h
@@ -32,7 +32,7 @@ class RawCvSource : public RawSource {
    * @param name Source name (arbitrary unique identifier)
    * @param mode Video mode being generated
    */
-  RawCvSource(const wpi::Twine& name, const VideoMode& mode);
+  RawCvSource(std::string_view name, const VideoMode& mode);
 
   /**
    * Create a Raw OpenCV source.
@@ -43,7 +43,7 @@ class RawCvSource : public RawSource {
    * @param height height
    * @param fps fps
    */
-  RawCvSource(const wpi::Twine& name, VideoMode::PixelFormat pixelFormat,
+  RawCvSource(std::string_view name, VideoMode::PixelFormat pixelFormat,
               int width, int height, int fps);
 
   /**
@@ -83,7 +83,7 @@ class RawCvSink : public RawSink {
    *
    * @param name Source name (arbitrary unique identifier)
    */
-  explicit RawCvSink(const wpi::Twine& name);
+  explicit RawCvSink(std::string_view name);
 
   /**
    * Create a sink for accepting OpenCV images in a separate thread.
@@ -97,7 +97,7 @@ class RawCvSink : public RawSink {
    *        or GetError() as needed, but should not call (except in very
    *        unusual circumstances) WaitForImage().
    */
-  RawCvSink(const wpi::Twine& name,
+  RawCvSink(std::string_view name,
             std::function<void(uint64_t time)> processFrame);
 
   /**
@@ -146,10 +146,10 @@ class RawCvSink : public RawSink {
   RawFrame rawFrame;
 };
 
-inline RawCvSource::RawCvSource(const wpi::Twine& name, const VideoMode& mode)
+inline RawCvSource::RawCvSource(std::string_view name, const VideoMode& mode)
     : RawSource{name, mode} {}
 
-inline RawCvSource::RawCvSource(const wpi::Twine& name,
+inline RawCvSource::RawCvSource(std::string_view name,
                                 VideoMode::PixelFormat format, int width,
                                 int height, int fps)
     : RawSource{name, format, width, height, fps} {}
@@ -164,9 +164,9 @@ inline void RawCvSource::PutFrame(cv::Mat& image) {
   PutSourceFrame(m_handle, rawFrame, &m_status);
 }
 
-inline RawCvSink::RawCvSink(const wpi::Twine& name) : RawSink{name} {}
+inline RawCvSink::RawCvSink(std::string_view name) : RawSink{name} {}
 
-inline RawCvSink::RawCvSink(const wpi::Twine& name,
+inline RawCvSink::RawCvSink(std::string_view name,
                             std::function<void(uint64_t time)> processFrame)
     : RawSink{name, processFrame} {}
 
diff --git a/cscore/src/main/native/linux/NetworkListener.cpp b/cscore/src/main/native/linux/NetworkListener.cpp
index bab556fb9b..1a0ac8b595 100644
--- a/cscore/src/main/native/linux/NetworkListener.cpp
+++ b/cscore/src/main/native/linux/NetworkListener.cpp
@@ -70,15 +70,15 @@ void NetworkListener::Impl::Thread::Main() {
   // Create event socket so we can be shut down
   m_command_fd = ::eventfd(0, 0);
   if (m_command_fd < 0) {
-    ERROR(
-        "NetworkListener: could not create eventfd: " << std::strerror(errno));
+    ERROR("NetworkListener: could not create eventfd: {}",
+          std::strerror(errno));
     return;
   }
 
   // Create netlink socket
   int sd = ::socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
   if (sd < 0) {
-    ERROR("NetworkListener: could not create socket: " << std::strerror(errno));
+    ERROR("NetworkListener: could not create socket: {}", std::strerror(errno));
     ::close(m_command_fd);
     m_command_fd = -1;
     return;
@@ -90,7 +90,7 @@ void NetworkListener::Impl::Thread::Main() {
   addr.nl_family = AF_NETLINK;
   addr.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR;
   if (bind(sd, reinterpret_cast<struct sockaddr*>(&addr), sizeof(addr)) < 0) {
-    ERROR("NetworkListener: could not create socket: " << std::strerror(errno));
+    ERROR("NetworkListener: could not create socket: {}", std::strerror(errno));
     ::close(sd);
     ::close(m_command_fd);
     m_command_fd = -1;
@@ -113,7 +113,7 @@ void NetworkListener::Impl::Thread::Main() {
     int nfds = std::max(m_command_fd, sd) + 1;
 
     if (::select(nfds, &readfds, nullptr, nullptr, &tv) < 0) {
-      ERROR("NetworkListener: select(): " << std::strerror(errno));
+      ERROR("NetworkListener: select(): {}", std::strerror(errno));
       break;  // XXX: is this the right thing to do here?
     }
 
@@ -134,8 +134,8 @@ void NetworkListener::Impl::Thread::Main() {
       if (errno == EWOULDBLOCK || errno == EAGAIN) {
         continue;
       }
-      ERROR(
-          "NetworkListener: could not read netlink: " << std::strerror(errno));
+      ERROR("NetworkListener: could not read netlink: {}",
+            std::strerror(errno));
       break;  // XXX: is this the right thing to do here?
     }
     if (len == 0) {
diff --git a/cscore/src/main/native/linux/UsbCameraImpl.cpp b/cscore/src/main/native/linux/UsbCameraImpl.cpp
index 8a05bee765..3e84578d18 100644
--- a/cscore/src/main/native/linux/UsbCameraImpl.cpp
+++ b/cscore/src/main/native/linux/UsbCameraImpl.cpp
@@ -22,8 +22,10 @@
 #include <algorithm>
 #include <memory>
 
+#include <fmt/format.h>
 #include <wpi/MemAlloc.h>
 #include <wpi/SmallString.h>
+#include <wpi/StringExtras.h>
 #include <wpi/fs.h>
 #include <wpi/raw_ostream.h>
 #include <wpi/timestamp.h>
@@ -95,8 +97,8 @@ static __u32 FromPixelFormat(VideoMode::PixelFormat pixelFormat) {
   }
 }
 
-static bool IsPercentageProperty(wpi::StringRef name) {
-  if (name.startswith("raw_")) {
+static bool IsPercentageProperty(std::string_view name) {
+  if (wpi::starts_with(name, "raw_")) {
     name = name.substr(4);
   }
   return name == "brightness" || name == "contrast" || name == "saturation" ||
@@ -154,11 +156,8 @@ int UsbCameraImpl::PercentageToRaw(const UsbCameraProperty& rawProp,
 }
 
 static bool GetVendorProduct(int dev, int* vendor, int* product) {
-  wpi::SmallString<64> ifpath;
-  {
-    wpi::raw_svector_ostream oss{ifpath};
-    oss << "/sys/class/video4linux/video" << dev << "/device/modalias";
-  }
+  auto ifpath =
+      fmt::format("/sys/class/video4linux/video{}/device/modalias", dev);
 
   int fd = open(ifpath.c_str(), O_RDONLY);
   if (fd < 0) {
@@ -172,15 +171,17 @@ static bool GetVendorProduct(int dev, int* vendor, int* product) {
   if (n <= 0) {
     return false;
   }
-  wpi::StringRef readStr{readBuf};
-  if (readStr.substr(readStr.find('v'))
-          .substr(1, 4)
-          .getAsInteger(16, *vendor)) {
+  std::string_view readStr{readBuf};
+  if (auto v = wpi::parse_integer<int>(
+          readStr.substr(readStr.find('v')).substr(1, 4), 16)) {
+    *vendor = v.value();
+  } else {
     return false;
   }
-  if (readStr.substr(readStr.find('p'))
-          .substr(1, 4)
-          .getAsInteger(16, *product)) {
+  if (auto v = wpi::parse_integer<int>(
+          readStr.substr(readStr.find('p')).substr(1, 4), 16)) {
+    *product = v.value();
+  } else {
     return false;
   }
 
@@ -188,11 +189,8 @@ static bool GetVendorProduct(int dev, int* vendor, int* product) {
 }
 
 static bool GetDescriptionSysV4L(int dev, std::string* desc) {
-  wpi::SmallString<64> ifpath;
-  {
-    wpi::raw_svector_ostream oss{ifpath};
-    oss << "/sys/class/video4linux/video" << dev << "/device/interface";
-  }
+  auto ifpath =
+      fmt::format("/sys/class/video4linux/video{}/device/interface", dev);
 
   int fd = open(ifpath.c_str(), O_RDONLY);
   if (fd < 0) {
@@ -207,7 +205,7 @@ static bool GetDescriptionSysV4L(int dev, std::string* desc) {
     return false;
   }
 
-  *desc = wpi::StringRef(readBuf, n).rtrim();
+  *desc = wpi::rtrim(std::string_view(readBuf, n));
   return true;
 }
 
@@ -225,17 +223,16 @@ static bool GetDescriptionIoctl(const char* cpath, std::string* desc) {
   }
   close(fd);
 
-  wpi::StringRef card{reinterpret_cast<const char*>(vcap.card)};
+  std::string_view card{reinterpret_cast<const char*>(vcap.card)};
   // try to convert "UVC Camera (0000:0000)" into a better name
-  int vendor = 0;
-  int product = 0;
-  if (card.startswith("UVC Camera (") &&
-      !card.substr(12, 4).getAsInteger(16, vendor) &&
-      !card.substr(17, 4).getAsInteger(16, product)) {
-    wpi::SmallString<64> card2Buf;
-    wpi::StringRef card2 = GetUsbNameFromId(vendor, product, card2Buf);
+  std::optional<int> vendor;
+  std::optional<int> product;
+  if (wpi::starts_with(card, "UVC Camera (") &&
+      (vendor = wpi::parse_integer<int>(card.substr(12, 4), 16)) &&
+      (product = wpi::parse_integer<int>(card.substr(17, 4), 16))) {
+    std::string card2 = GetUsbNameFromId(vendor.value(), product.value());
     if (!card2.empty()) {
-      *desc = card2;
+      *desc = std::move(card2);
       return true;
     }
   }
@@ -274,15 +271,14 @@ static int GetDeviceNum(const char* cpath) {
     path = fs::canonical(path);
   }
 
-  auto fn = path.filename();
-  if (!wpi::StringRef{fn}.startswith("video")) {
+  std::string fn = path.filename();
+  if (!wpi::starts_with(fn, "video")) {
     return -1;
   }
-  int dev = -1;
-  if (wpi::StringRef{fn}.substr(5).getAsInteger(10, dev)) {
-    return -1;
+  if (auto dev = wpi::parse_integer<int>(fn.substr(5), 10)) {
+    return dev.value();
   }
-  return dev;
+  return -1;
 }
 
 static std::string GetDescriptionImpl(const char* cpath) {
@@ -304,14 +300,14 @@ static std::string GetDescriptionImpl(const char* cpath) {
   return std::string{};
 }
 
-UsbCameraImpl::UsbCameraImpl(const wpi::Twine& name, wpi::Logger& logger,
+UsbCameraImpl::UsbCameraImpl(std::string_view name, wpi::Logger& logger,
                              Notifier& notifier, Telemetry& telemetry,
-                             const wpi::Twine& path)
+                             std::string_view path)
     : SourceImpl{name, logger, notifier, telemetry},
       m_fd{-1},
       m_command_fd{eventfd(0, 0)},
       m_active{true},
-      m_path{path.str()} {
+      m_path{path} {
   SetDescription(GetDescriptionImpl(m_path.c_str()));
   SetQuirks();
 
@@ -439,7 +435,7 @@ void UsbCameraImpl::CameraThreadMain() {
     DoFdSet(notify_fd, &readfds, &nfds);
 
     if (select(nfds, &readfds, nullptr, nullptr, &tv) < 0) {
-      SERROR("select(): " << std::strerror(errno));
+      SERROR("select(): {}", std::strerror(errno));
       break;  // XXX: is this the right thing to do here?
     }
 
@@ -450,7 +446,7 @@ void UsbCameraImpl::CameraThreadMain() {
 
     // Handle notify events
     if (notify_fd >= 0 && FD_ISSET(notify_fd, &readfds)) {
-      SDEBUG4("notify event");
+      SDEBUG4("{}", "notify event");
       struct inotify_event event;
       do {
         // Read the event structure
@@ -460,10 +456,9 @@ void UsbCameraImpl::CameraThreadMain() {
         raw_name.resize(event.len);
         notify_is->read(raw_name.data(), event.len);
         // If the name is what we expect...
-        wpi::StringRef name{raw_name.c_str()};
-        SDEBUG4("got event on '" << name << "' (" << name.size()
-                                 << ") compare to '" << base << "' ("
-                                 << base.size() << ") mask " << event.mask);
+        std::string_view name{raw_name.c_str()};
+        SDEBUG4("got event on '{}' ({}) compare to '{}' ({}) mask {}", name,
+                name.size(), base, base.size(), event.mask);
         if (name == base) {
           if ((event.mask & IN_DELETE) != 0) {
             wasStreaming = m_streaming;
@@ -480,7 +475,7 @@ void UsbCameraImpl::CameraThreadMain() {
 
     // Handle commands
     if (command_fd >= 0 && FD_ISSET(command_fd, &readfds)) {
-      SDEBUG4("got command");
+      SDEBUG4("{}", "got command");
       // Read it to clear
       eventfd_t val;
       eventfd_read(command_fd, &val);
@@ -490,7 +485,7 @@ void UsbCameraImpl::CameraThreadMain() {
 
     // Handle frames
     if (m_streaming && fd >= 0 && FD_ISSET(fd, &readfds)) {
-      SDEBUG4("grabbing image");
+      SDEBUG4("{}", "grabbing image");
 
       // Dequeue buffer
       struct v4l2_buffer buf;
@@ -498,7 +493,7 @@ void UsbCameraImpl::CameraThreadMain() {
       buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
       buf.memory = V4L2_MEMORY_MMAP;
       if (DoIoctl(fd, VIDIOC_DQBUF, &buf) != 0) {
-        SWARNING("could not dequeue buffer");
+        SWARNING("{}", "could not dequeue buffer");
         wasStreaming = m_streaming;
         DeviceStreamOff();
         DeviceDisconnect();
@@ -507,14 +502,14 @@ void UsbCameraImpl::CameraThreadMain() {
       }
 
       if ((buf.flags & V4L2_BUF_FLAG_ERROR) == 0) {
-        SDEBUG4("got image size=" << buf.bytesused << " index=" << buf.index);
+        SDEBUG4("got image size={} index={}", buf.bytesused, buf.index);
 
         if (buf.index >= kNumBuffers || !m_buffers[buf.index].m_data) {
-          SWARNING("invalid buffer" << buf.index);
+          SWARNING("invalid buffer {}", buf.index);
           continue;
         }
 
-        wpi::StringRef image{
+        std::string_view image{
             static_cast<const char*>(m_buffers[buf.index].m_data),
             static_cast<size_t>(buf.bytesused)};
         int width = m_mode.width;
@@ -522,7 +517,7 @@ void UsbCameraImpl::CameraThreadMain() {
         bool good = true;
         if (m_mode.pixelFormat == VideoMode::kMJPEG &&
             !GetJpegSize(image, &width, &height)) {
-          SWARNING("invalid JPEG image received from camera");
+          SWARNING("{}", "invalid JPEG image received from camera");
           good = false;
         }
         if (good) {
@@ -533,7 +528,7 @@ void UsbCameraImpl::CameraThreadMain() {
 
       // Requeue buffer
       if (DoIoctl(fd, VIDIOC_QBUF, &buf) != 0) {
-        SWARNING("could not requeue buffer");
+        SWARNING("{}", "could not requeue buffer");
         wasStreaming = m_streaming;
         DeviceStreamOff();
         DeviceDisconnect();
@@ -572,11 +567,11 @@ void UsbCameraImpl::DeviceConnect() {
   }
 
   if (m_connectVerbose) {
-    SINFO("Connecting to USB camera on " << m_path);
+    SINFO("Connecting to USB camera on {}", m_path);
   }
 
   // Try to open the device
-  SDEBUG3("opening device");
+  SDEBUG3("{}", "opening device");
   int fd = open(m_path.c_str(), O_RDWR);
   if (fd < 0) {
     return;
@@ -584,7 +579,7 @@ void UsbCameraImpl::DeviceConnect() {
   m_fd = fd;
 
   // Get capabilities
-  SDEBUG3("getting capabilities");
+  SDEBUG3("{}", "getting capabilities");
   struct v4l2_capability vcap;
   std::memset(&vcap, 0, sizeof(vcap));
   if (DoIoctl(fd, VIDIOC_QUERYCAP, &vcap) >= 0) {
@@ -596,18 +591,18 @@ void UsbCameraImpl::DeviceConnect() {
 
   // Get or restore video mode
   if (!m_properties_cached) {
-    SDEBUG3("caching properties");
+    SDEBUG3("{}", "caching properties");
     DeviceCacheProperties();
     DeviceCacheVideoModes();
     DeviceCacheMode();
     m_properties_cached = true;
   } else {
-    SDEBUG3("restoring video mode");
+    SDEBUG3("{}", "restoring video mode");
     DeviceSetMode();
     DeviceSetFPS();
 
     // Restore settings
-    SDEBUG3("restoring settings");
+    SDEBUG3("{}", "restoring settings");
     std::unique_lock lock2(m_mutex);
     for (size_t i = 0; i < m_propertyData.size(); ++i) {
       const auto prop =
@@ -616,27 +611,27 @@ void UsbCameraImpl::DeviceConnect() {
         continue;
       }
       if (!prop->DeviceSet(lock2, m_fd)) {
-        SWARNING("failed to set property " << prop->name);
+        SWARNING("failed to set property {}", prop->name);
       }
     }
   }
 
   // Request buffers
-  SDEBUG3("allocating buffers");
+  SDEBUG3("{}", "allocating buffers");
   struct v4l2_requestbuffers rb;
   std::memset(&rb, 0, sizeof(rb));
   rb.count = kNumBuffers;
   rb.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
   rb.memory = V4L2_MEMORY_MMAP;
   if (DoIoctl(fd, VIDIOC_REQBUFS, &rb) != 0) {
-    SWARNING("could not allocate buffers");
+    SWARNING("{}", "could not allocate buffers");
     close(fd);
     m_fd = -1;
     return;
   }
 
   // Map buffers
-  SDEBUG3("mapping buffers");
+  SDEBUG3("{}", "mapping buffers");
   for (int i = 0; i < kNumBuffers; ++i) {
     struct v4l2_buffer buf;
     std::memset(&buf, 0, sizeof(buf));
@@ -644,17 +639,16 @@ void UsbCameraImpl::DeviceConnect() {
     buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
     buf.memory = V4L2_MEMORY_MMAP;
     if (DoIoctl(fd, VIDIOC_QUERYBUF, &buf) != 0) {
-      SWARNING("could not query buffer " << i);
+      SWARNING("could not query buffer {}", i);
       close(fd);
       m_fd = -1;
       return;
     }
-    SDEBUG4("buf " << i << " length=" << buf.length
-                   << " offset=" << buf.m.offset);
+    SDEBUG4("buf {} length={} offset={}", i, buf.length, buf.m.offset);
 
     m_buffers[i] = UsbCameraBuffer(fd, buf.length, buf.m.offset);
     if (!m_buffers[i].m_data) {
-      SWARNING("could not map buffer " << i);
+      SWARNING("could not map buffer {}", i);
       // release other buffers
       for (int j = 0; j < i; ++j) {
         m_buffers[j] = UsbCameraBuffer{};
@@ -664,7 +658,7 @@ void UsbCameraImpl::DeviceConnect() {
       return;
     }
 
-    SDEBUG4("buf " << i << " address=" << m_buffers[i].m_data);
+    SDEBUG4("buf {} address={}", i, m_buffers[i].m_data);
   }
 
   // Update description (as it may have changed)
@@ -687,7 +681,7 @@ bool UsbCameraImpl::DeviceStreamOn() {
   }
 
   // Queue buffers
-  SDEBUG3("queuing buffers");
+  SDEBUG3("{}", "queuing buffers");
   for (int i = 0; i < kNumBuffers; ++i) {
     struct v4l2_buffer buf;
     std::memset(&buf, 0, sizeof(buf));
@@ -695,7 +689,7 @@ bool UsbCameraImpl::DeviceStreamOn() {
     buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
     buf.memory = V4L2_MEMORY_MMAP;
     if (DoIoctl(fd, VIDIOC_QBUF, &buf) != 0) {
-      SWARNING("could not queue buffer " << i);
+      SWARNING("could not queue buffer {}", i);
       return false;
     }
   }
@@ -706,16 +700,17 @@ bool UsbCameraImpl::DeviceStreamOn() {
     if (errno == ENOSPC) {
       // indicates too much USB bandwidth requested
       SERROR(
+          "{}",
           "could not start streaming due to USB bandwidth limitations; try a "
           "lower resolution or a different pixel format (VIDIOC_STREAMON: "
           "No space left on device)");
     } else {
       // some other error
-      SERROR("ioctl VIDIOC_STREAMON failed: " << std::strerror(errno));
+      SERROR("ioctl VIDIOC_STREAMON failed: {}", std::strerror(errno));
     }
     return false;
   }
-  SDEBUG4("enabled streaming");
+  SDEBUG4("{}", "enabled streaming");
   m_streaming = true;
   return true;
 }
@@ -732,7 +727,7 @@ bool UsbCameraImpl::DeviceStreamOff() {
   if (DoIoctl(fd, VIDIOC_STREAMOFF, &type) != 0) {
     return false;
   }
-  SDEBUG4("disabled streaming");
+  SDEBUG4("{}", "disabled streaming");
   m_streaming = false;
   return true;
 }
@@ -806,7 +801,7 @@ CS_StatusValue UsbCameraImpl::DeviceCmdSetProperty(
   bool setString = (msg.kind == Message::kCmdSetPropertyStr);
   int property = msg.data[0];
   int value = msg.data[1];
-  wpi::StringRef valueStr = msg.dataStr;
+  std::string_view valueStr = msg.dataStr;
 
   // Look up
   auto prop = static_cast<UsbCameraProperty*>(GetProperty(property));
@@ -940,19 +935,19 @@ void UsbCameraImpl::DeviceSetMode() {
   vfmt.fmt.pix.pixelformat =
       FromPixelFormat(static_cast<VideoMode::PixelFormat>(m_mode.pixelFormat));
   if (vfmt.fmt.pix.pixelformat == 0) {
-    SWARNING("could not set format " << m_mode.pixelFormat
-                                     << ", defaulting to MJPEG");
+    SWARNING("could not set format {}, defaulting to MJPEG",
+             m_mode.pixelFormat);
     vfmt.fmt.pix.pixelformat = V4L2_PIX_FMT_MJPEG;
   }
   vfmt.fmt.pix.width = m_mode.width;
   vfmt.fmt.pix.height = m_mode.height;
   vfmt.fmt.pix.field = V4L2_FIELD_ANY;
   if (DoIoctl(fd, VIDIOC_S_FMT, &vfmt) != 0) {
-    SWARNING("could not set format " << m_mode.pixelFormat << " res "
-                                     << m_mode.width << "x" << m_mode.height);
+    SWARNING("could not set format {} res {}x{}", m_mode.pixelFormat,
+             m_mode.width, m_mode.height);
   } else {
-    SINFO("set format " << m_mode.pixelFormat << " res " << m_mode.width << "x"
-                        << m_mode.height);
+    SINFO("set format {} res {}x{}", m_mode.pixelFormat, m_mode.width,
+          m_mode.height);
   }
 }
 
@@ -975,9 +970,9 @@ void UsbCameraImpl::DeviceSetFPS() {
   parm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
   parm.parm.capture.timeperframe = FPSToFract(m_mode.fps);
   if (DoIoctl(fd, VIDIOC_S_PARM, &parm) != 0) {
-    SWARNING("could not set FPS to " << m_mode.fps);
+    SWARNING("could not set FPS to {}", m_mode.fps);
   } else {
-    SINFO("set FPS to " << m_mode.fps);
+    SINFO("set FPS to {}", m_mode.fps);
   }
 }
 
@@ -997,7 +992,7 @@ void UsbCameraImpl::DeviceCacheMode() {
 #endif
   vfmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
   if (DoIoctl(fd, VIDIOC_G_FMT, &vfmt) != 0) {
-    SERROR("could not read current video mode");
+    SERROR("{}", "could not read current video mode");
     std::scoped_lock lock(m_mutex);
     m_mode = VideoMode{VideoMode::kMJPEG, 320, 240, 30};
     return;
@@ -1133,7 +1128,7 @@ void UsbCameraImpl::DeviceCacheProperty(
   } else {
     // Read current raw value and set percentage from it
     if (!rawProp->DeviceGet(lock, m_fd)) {
-      SWARNING("failed to get property " << rawProp->name);
+      SWARNING("failed to get property {}", rawProp->name);
     }
 
     if (perProp) {
@@ -1145,7 +1140,7 @@ void UsbCameraImpl::DeviceCacheProperty(
   // Set value on device if user-configured
   if (rawProp->valueSet) {
     if (!rawProp->DeviceSet(lock, m_fd)) {
-      SWARNING("failed to set property " << rawProp->name);
+      SWARNING("failed to set property {}", rawProp->name);
     }
   }
 
@@ -1360,7 +1355,7 @@ void UsbCameraImpl::Send(Message&& msg) const {
 }
 
 std::unique_ptr<PropertyImpl> UsbCameraImpl::CreateEmptyProperty(
-    const wpi::Twine& name) const {
+    std::string_view name) const {
   return std::make_unique<UsbCameraProperty>(name);
 }
 
@@ -1379,10 +1374,10 @@ bool UsbCameraImpl::CacheProperties(CS_Status* status) const {
 
 void UsbCameraImpl::SetQuirks() {
   wpi::SmallString<128> descbuf;
-  wpi::StringRef desc = GetDescription(descbuf);
-  m_lifecam_exposure =
-      desc.endswith("LifeCam HD-3000") || desc.endswith("LifeCam Cinema (TM)");
-  m_picamera = desc.startswith("mmal service");
+  std::string_view desc = GetDescription(descbuf);
+  m_lifecam_exposure = wpi::ends_with(desc, "LifeCam HD-3000") ||
+                       wpi::ends_with(desc, "LifeCam Cinema (TM)");
+  m_picamera = wpi::ends_with(desc, "mmal service");
 
   int deviceNum = GetDeviceNum(m_path.c_str());
   if (deviceNum >= 0) {
@@ -1400,11 +1395,11 @@ void UsbCameraImpl::SetProperty(int property, int value, CS_Status* status) {
   *status = SendAndWait(std::move(msg));
 }
 
-void UsbCameraImpl::SetStringProperty(int property, const wpi::Twine& value,
+void UsbCameraImpl::SetStringProperty(int property, std::string_view value,
                                       CS_Status* status) {
   Message msg{Message::kCmdSetPropertyStr};
   msg.data[0] = property;
-  msg.dataStr = value.str();
+  msg.dataStr = value;
   *status = SendAndWait(std::move(msg));
 }
 
@@ -1524,9 +1519,9 @@ void UsbCameraImpl::NumSinksEnabledChanged() {
   Send(Message{Message::kNumSinksEnabledChanged});
 }
 
-void UsbCameraImpl::SetPath(const wpi::Twine& path, CS_Status* status) {
+void UsbCameraImpl::SetPath(std::string_view path, CS_Status* status) {
   Message msg{Message::kCmdSetPath};
-  msg.dataStr = path.str();
+  msg.dataStr = path;
   *status = SendAndWait(std::move(msg));
 }
 
@@ -1537,15 +1532,12 @@ std::string UsbCameraImpl::GetPath() const {
 
 namespace cs {
 
-CS_Source CreateUsbCameraDev(const wpi::Twine& name, int dev,
+CS_Source CreateUsbCameraDev(std::string_view name, int dev,
                              CS_Status* status) {
-  wpi::SmallString<32> path;
-  wpi::raw_svector_ostream oss{path};
-  oss << "/dev/video" << dev;
-  return CreateUsbCameraPath(name, oss.str(), status);
+  return CreateUsbCameraPath(name, fmt::format("/dev/video{}", dev), status);
 }
 
-CS_Source CreateUsbCameraPath(const wpi::Twine& name, const wpi::Twine& path,
+CS_Source CreateUsbCameraPath(std::string_view name, std::string_view path,
                               CS_Status* status) {
   auto& inst = Instance::GetInstance();
   return inst.CreateSource(CS_SOURCE_USB, std::make_shared<UsbCameraImpl>(
@@ -1553,7 +1545,7 @@ CS_Source CreateUsbCameraPath(const wpi::Twine& name, const wpi::Twine& path,
                                               inst.telemetry, path));
 }
 
-void SetUsbCameraPath(CS_Source source, const wpi::Twine& path,
+void SetUsbCameraPath(CS_Source source, std::string_view path,
                       CS_Status* status) {
   auto data = Instance::GetInstance().GetSource(source);
   if (!data || data->kind != CS_SOURCE_USB) {
@@ -1629,13 +1621,15 @@ std::vector<UsbCameraInfo> EnumerateUsbCameras(CS_Status* status) {
 
   if (DIR* dp = ::opendir("/dev")) {
     while (struct dirent* ep = ::readdir(dp)) {
-      wpi::StringRef fname{ep->d_name};
-      if (!fname.startswith("video")) {
+      std::string_view fname{ep->d_name};
+      if (!wpi::starts_with(fname, "video")) {
         continue;
       }
 
       unsigned int dev = 0;
-      if (fname.substr(5).getAsInteger(10, dev)) {
+      if (auto v = wpi::parse_integer<unsigned int>(fname.substr(5), 10)) {
+        dev = v.value();
+      } else {
         continue;
       }
 
@@ -1665,7 +1659,7 @@ std::vector<UsbCameraInfo> EnumerateUsbCameras(CS_Status* status) {
     ::closedir(dp);
   } else {
     // *status = ;
-    WPI_ERROR(Instance::GetInstance().logger, "Could not open /dev");
+    WPI_ERROR(Instance::GetInstance().logger, "{}", "Could not open /dev");
     return retval;
   }
 
@@ -1682,11 +1676,11 @@ std::vector<UsbCameraInfo> EnumerateUsbCameras(CS_Status* status) {
           char* target = ::realpath(path.c_str(), nullptr);
           if (target) {
             std::string fname = fs::path{target}.filename();
-            unsigned int dev = 0;
-            if (wpi::StringRef{fname}.startswith("video") &&
-                !wpi::StringRef{fname}.substr(5).getAsInteger(10, dev) &&
-                dev < retval.size()) {
-              retval[dev].otherPaths.emplace_back(path.str());
+            std::optional<unsigned int> dev;
+            if (wpi::starts_with(fname, "video") &&
+                (dev = wpi::parse_integer<unsigned int>(fname.substr(5), 10)) &&
+                dev.value() < retval.size()) {
+              retval[dev.value()].otherPaths.emplace_back(path.str());
             }
             std::free(target);
           }
diff --git a/cscore/src/main/native/linux/UsbCameraImpl.h b/cscore/src/main/native/linux/UsbCameraImpl.h
index edfd2d5bad..c0273431ee 100644
--- a/cscore/src/main/native/linux/UsbCameraImpl.h
+++ b/cscore/src/main/native/linux/UsbCameraImpl.h
@@ -10,13 +10,13 @@
 #include <atomic>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <thread>
 #include <utility>
 #include <vector>
 
 #include <wpi/STLExtras.h>
 #include <wpi/SmallVector.h>
-#include <wpi/Twine.h>
 #include <wpi/condition_variable.h>
 #include <wpi/mutex.h>
 #include <wpi/raw_istream.h>
@@ -33,15 +33,15 @@ class Telemetry;
 
 class UsbCameraImpl : public SourceImpl {
  public:
-  UsbCameraImpl(const wpi::Twine& name, wpi::Logger& logger, Notifier& notifier,
-                Telemetry& telemetry, const wpi::Twine& path);
+  UsbCameraImpl(std::string_view name, wpi::Logger& logger, Notifier& notifier,
+                Telemetry& telemetry, std::string_view path);
   ~UsbCameraImpl() override;
 
   void Start() override;
 
   // Property functions
   void SetProperty(int property, int value, CS_Status* status) override;
-  void SetStringProperty(int property, const wpi::Twine& value,
+  void SetStringProperty(int property, std::string_view value,
                          CS_Status* status) override;
 
   // Standard common camera properties
@@ -63,7 +63,7 @@ class UsbCameraImpl : public SourceImpl {
   void NumSinksChanged() override;
   void NumSinksEnabledChanged() override;
 
-  void SetPath(const wpi::Twine& path, CS_Status* status);
+  void SetPath(std::string_view path, CS_Status* status);
   std::string GetPath() const;
 
   // Messages passed to/from camera thread
@@ -95,7 +95,7 @@ class UsbCameraImpl : public SourceImpl {
 
  protected:
   std::unique_ptr<PropertyImpl> CreateEmptyProperty(
-      const wpi::Twine& name) const override;
+      std::string_view name) const override;
 
   // Cache properties.  Immediately successful if properties are already cached.
   // If they are not, tries to connect to the camera to do so; returns false and
diff --git a/cscore/src/main/native/linux/UsbCameraListener.cpp b/cscore/src/main/native/linux/UsbCameraListener.cpp
index 7c73b79876..40e84c5daf 100644
--- a/cscore/src/main/native/linux/UsbCameraListener.cpp
+++ b/cscore/src/main/native/linux/UsbCameraListener.cpp
@@ -5,6 +5,7 @@
 #include "UsbCameraListener.h"
 
 #include <wpi/EventLoopRunner.h>
+#include <wpi/StringExtras.h>
 #include <wpi/uv/FsEvent.h>
 #include <wpi/uv/Timer.h>
 
@@ -38,7 +39,7 @@ void UsbCameraListener::Start() {
 
       auto devEvents = wpi::uv::FsEvent::Create(loop);
       devEvents->fsEvent.connect([refreshTimer](const char* fn, int flags) {
-        if (wpi::StringRef(fn).startswith("video")) {
+        if (wpi::starts_with(fn, "video")) {
           refreshTimer->Start(wpi::uv::Timer::Time(200));
         }
       });
diff --git a/cscore/src/main/native/linux/UsbCameraProperty.cpp b/cscore/src/main/native/linux/UsbCameraProperty.cpp
index f2ec84839d..149ca1b979 100644
--- a/cscore/src/main/native/linux/UsbCameraProperty.cpp
+++ b/cscore/src/main/native/linux/UsbCameraProperty.cpp
@@ -4,8 +4,8 @@
 
 #include "UsbCameraProperty.h"
 
+#include <fmt/format.h>
 #include <wpi/SmallString.h>
-#include <wpi/raw_ostream.h>
 
 #include "UsbUtil.h"
 
@@ -92,15 +92,8 @@ static int GetStringCtrlIoctl(int fd, int id, int maximum, std::string* value) {
 }
 
 static int SetStringCtrlIoctl(int fd, int id, int maximum,
-                              const wpi::Twine& value) {
-  wpi::SmallString<64> strBuf, strBuf2;
-  wpi::StringRef str = value.toNullTerminatedStringRef(strBuf);
-  if (str.size() > static_cast<size_t>(maximum)) {
-    // don't know if strBuf was used, just recopy
-    strBuf2 = str.take_front(maximum);
-    str = strBuf2;
-    strBuf2.push_back('\0');  // null terminate
-  }
+                              std::string_view value) {
+  wpi::SmallString<64> str{value.substr(0, maximum)};
 
   struct v4l2_ext_control ctrl;
   struct v4l2_ext_controls ctrls;
@@ -108,7 +101,7 @@ static int SetStringCtrlIoctl(int fd, int id, int maximum,
   std::memset(&ctrls, 0, sizeof(ctrls));
   ctrl.id = id;
   ctrl.size = str.size();
-  ctrl.string = const_cast<char*>(str.data());
+  ctrl.string = const_cast<char*>(str.c_str());
   ctrls.ctrl_class = V4L2_CTRL_ID2CLASS(id);
   ctrls.count = 1;
   ctrls.controls = &ctrl;
@@ -117,8 +110,8 @@ static int SetStringCtrlIoctl(int fd, int id, int maximum,
 
 // Removes non-alphanumeric characters and replaces spaces with underscores.
 // e.g. "Zoom, Absolute" -> "zoom_absolute", "Pan (Absolute)" -> "pan_absolute"
-static wpi::StringRef NormalizeName(wpi::StringRef name,
-                                    wpi::SmallVectorImpl<char>& buf) {
+static std::string_view NormalizeName(std::string_view name,
+                                      wpi::SmallVectorImpl<char>& buf) {
   bool newWord = false;
   for (auto ch : name) {
     if (std::isalnum(ch)) {
@@ -131,13 +124,12 @@ static wpi::StringRef NormalizeName(wpi::StringRef name,
       newWord = true;
     }
   }
-  return wpi::StringRef(buf.data(), buf.size());
+  return {buf.data(), buf.size()};
 }
 
 #ifdef VIDIOC_QUERY_EXT_CTRL
 UsbCameraProperty::UsbCameraProperty(const struct v4l2_query_ext_ctrl& ctrl)
-    : PropertyImpl(wpi::StringRef{}, CS_PROP_NONE, ctrl.step,
-                   ctrl.default_value, 0),
+    : PropertyImpl({}, CS_PROP_NONE, ctrl.step, ctrl.default_value, 0),
       id(ctrl.id & V4L2_CTRL_ID_MASK),
       type(ctrl.type) {
   hasMinimum = true;
@@ -174,13 +166,12 @@ UsbCameraProperty::UsbCameraProperty(const struct v4l2_query_ext_ctrl& ctrl)
     ++len;
   }
   wpi::SmallString<64> name_buf;
-  name = NormalizeName(wpi::StringRef(ctrl.name, len), name_buf);
+  name = NormalizeName({ctrl.name, len}, name_buf);
 }
 #endif
 
 UsbCameraProperty::UsbCameraProperty(const struct v4l2_queryctrl& ctrl)
-    : PropertyImpl(wpi::StringRef{}, CS_PROP_NONE, ctrl.step,
-                   ctrl.default_value, 0),
+    : PropertyImpl({}, CS_PROP_NONE, ctrl.step, ctrl.default_value, 0),
       id(ctrl.id & V4L2_CTRL_ID_MASK),
       type(ctrl.type) {
   hasMinimum = true;
@@ -214,8 +205,8 @@ UsbCameraProperty::UsbCameraProperty(const struct v4l2_queryctrl& ctrl)
     ++len;
   }
   wpi::SmallString<64> name_buf;
-  name = NormalizeName(
-      wpi::StringRef(reinterpret_cast<const char*>(ctrl.name), len), name_buf);
+  name =
+      NormalizeName({reinterpret_cast<const char*>(ctrl.name), len}, name_buf);
 }
 
 std::unique_ptr<UsbCameraProperty> UsbCameraProperty::DeviceQuery(int fd,
@@ -261,8 +252,7 @@ std::unique_ptr<UsbCameraProperty> UsbCameraProperty::DeviceQuery(int fd,
         continue;
       }
       if (prop->intMenu) {
-        wpi::raw_string_ostream os(prop->enumChoices[i]);
-        os << qmenu.value;
+        prop->enumChoices[i] = fmt::to_string(qmenu.value);
       } else {
         prop->enumChoices[i] = reinterpret_cast<const char*>(qmenu.name);
       }
@@ -315,12 +305,12 @@ bool UsbCameraProperty::DeviceSet(std::unique_lock<wpi::mutex>& lock,
                                   int fd) const {
   // Make a copy of the string as we're about to release the lock
   wpi::SmallString<128> valueStrCopy{valueStr};
-  return DeviceSet(lock, fd, value, valueStrCopy);
+  return DeviceSet(lock, fd, value, valueStrCopy.str());
 }
 
 bool UsbCameraProperty::DeviceSet(std::unique_lock<wpi::mutex>& lock, int fd,
                                   int newValue,
-                                  const wpi::Twine& newValueStr) const {
+                                  std::string_view newValueStr) const {
   if (!device || fd < 0) {
     return true;
   }
diff --git a/cscore/src/main/native/linux/UsbCameraProperty.h b/cscore/src/main/native/linux/UsbCameraProperty.h
index c608e00fd6..b0291a17eb 100644
--- a/cscore/src/main/native/linux/UsbCameraProperty.h
+++ b/cscore/src/main/native/linux/UsbCameraProperty.h
@@ -8,6 +8,7 @@
 #include <linux/videodev2.h>
 
 #include <memory>
+#include <string_view>
 
 #include <wpi/mutex.h>
 
@@ -19,19 +20,19 @@ namespace cs {
 class UsbCameraProperty : public PropertyImpl {
  public:
   UsbCameraProperty() = default;
-  explicit UsbCameraProperty(const wpi::Twine& name_) : PropertyImpl{name_} {}
+  explicit UsbCameraProperty(std::string_view name_) : PropertyImpl{name_} {}
 
   // Software property constructor
-  UsbCameraProperty(const wpi::Twine& name_, unsigned id_,
-                    CS_PropertyKind kind_, int minimum_, int maximum_,
-                    int step_, int defaultValue_, int value_)
+  UsbCameraProperty(std::string_view name_, unsigned id_, CS_PropertyKind kind_,
+                    int minimum_, int maximum_, int step_, int defaultValue_,
+                    int value_)
       : PropertyImpl(name_, kind_, minimum_, maximum_, step_, defaultValue_,
                      value_),
         device{false},
         id{id_} {}
 
   // Normalized property constructor
-  UsbCameraProperty(const wpi::Twine& name_, int rawIndex_,
+  UsbCameraProperty(std::string_view name_, int rawIndex_,
                     const UsbCameraProperty& rawProp, int defaultValue_,
                     int value_)
       : PropertyImpl(name_, rawProp.propKind, 1, defaultValue_, value_),
@@ -55,7 +56,7 @@ class UsbCameraProperty : public PropertyImpl {
   bool DeviceGet(std::unique_lock<wpi::mutex>& lock, int fd);
   bool DeviceSet(std::unique_lock<wpi::mutex>& lock, int fd) const;
   bool DeviceSet(std::unique_lock<wpi::mutex>& lock, int fd, int newValue,
-                 const wpi::Twine& newValueStr) const;
+                 std::string_view newValueStr) const;
 
   // If this is a device (rather than software) property
   bool device{true};
diff --git a/cscore/src/main/native/linux/UsbUtil.cpp b/cscore/src/main/native/linux/UsbUtil.cpp
index c2aff2972b..afe3e4218d 100644
--- a/cscore/src/main/native/linux/UsbUtil.cpp
+++ b/cscore/src/main/native/linux/UsbUtil.cpp
@@ -8,8 +8,10 @@
 #include <libgen.h>
 #include <sys/ioctl.h>
 
-#include <wpi/Format.h>
+#include <fmt/format.h>
 #include <wpi/SmallString.h>
+#include <wpi/StringExtras.h>
+#include <wpi/fs.h>
 #include <wpi/raw_istream.h>
 #include <wpi/raw_ostream.h>
 
@@ -18,21 +20,18 @@
 
 namespace cs {
 
-static wpi::StringRef GetUsbNameFromFile(int vendor, int product,
-                                         wpi::SmallVectorImpl<char>& buf) {
+static std::string GetUsbNameFromFile(int vendor, int product) {
   int fd = open("/var/lib/usbutils/usb.ids", O_RDONLY);
   if (fd < 0) {
     return {};
   }
 
-  wpi::raw_svector_ostream os{buf};
+  wpi::SmallString<128> buf;
   wpi::raw_fd_istream is{fd, true};
 
   // build vendor and product 4-char hex strings
-  wpi::SmallString<16> vendorStr, productStr;
-  wpi::raw_svector_ostream vendorOs{vendorStr}, productOs{productStr};
-  vendorOs << wpi::format_hex_no_prefix(vendor, 4);
-  productOs << wpi::format_hex_no_prefix(product, 4);
+  auto vendorStr = fmt::format("{:04x}", vendor);
+  auto productStr = fmt::format("{:04x}", product);
 
   // scan file
   wpi::SmallString<128> lineBuf;
@@ -48,23 +47,24 @@ static wpi::StringRef GetUsbNameFromFile(int vendor, int product,
     }
 
     // look for vendor at start of line
-    if (line.startswith(vendorStr)) {
+    if (wpi::starts_with(line, vendorStr)) {
       foundVendor = true;
-      os << line.substr(5).trim() << ' ';
+      buf += wpi::trim(line.substr(5));
+      buf += ' ';
       continue;
     }
 
     if (foundVendor) {
       // next vendor, but didn't match product?
       if (line[0] != '\t') {
-        os << "Unknown";
-        return os.str();
+        buf += "Unknown";
+        return buf;
       }
 
       // look for product
-      if (line.substr(1).startswith(productStr)) {
-        os << line.substr(6).trim();
-        return os.str();
+      if (wpi::starts_with(line.substr(1), productStr)) {
+        buf += wpi::trim(line.substr(6));
+        return buf;
       }
     }
   }
@@ -72,93 +72,90 @@ static wpi::StringRef GetUsbNameFromFile(int vendor, int product,
   return {};
 }
 
-wpi::StringRef GetUsbNameFromId(int vendor, int product,
-                                wpi::SmallVectorImpl<char>& buf) {
+std::string GetUsbNameFromId(int vendor, int product) {
   // try reading usb.ids
-  wpi::StringRef rv = GetUsbNameFromFile(vendor, product, buf);
+  std::string rv = GetUsbNameFromFile(vendor, product);
   if (!rv.empty()) {
     return rv;
   }
 
   // Fall back to internal database
-  wpi::raw_svector_ostream os{buf};
   switch (vendor) {
-    case 0x046d:
-      os << "Logitech, Inc. ";
+    case 0x046d: {
+      std::string_view productStr;
       switch (product) {
         case 0x0802:
-          os << "Webcam C200";
+          productStr = "Webcam C200";
           break;
         case 0x0804:
-          os << "Webcam C250";
+          productStr = "Webcam C250";
           break;
         case 0x0805:
-          os << "Webcam C300";
+          productStr = "Webcam C300";
           break;
         case 0x0807:
-          os << "Webcam B500";
+          productStr = "Webcam B500";
           break;
         case 0x0808:
-          os << "Webcam C600";
+          productStr = "Webcam C600";
           break;
         case 0x0809:
-          os << "Webcam Pro 9000";
+          productStr = "Webcam Pro 9000";
           break;
         case 0x080a:
-          os << "Portable Webcam C905";
+          productStr = "Portable Webcam C905";
           break;
         case 0x080f:
-          os << "Webcam C120";
+          productStr = "Webcam C120";
           break;
         case 0x0819:
-          os << "Webcam C210";
+          productStr = "Webcam C210";
           break;
         case 0x081b:
-          os << "Webcam C310";
+          productStr = "Webcam C310";
           break;
         case 0x081d:
-          os << "HD Webcam C510";
+          productStr = "HD Webcam C510";
           break;
         case 0x0821:
-          os << "HD Webcam C910";
+          productStr = "HD Webcam C910";
           break;
         case 0x0825:
-          os << "Webcam C270";
+          productStr = "Webcam C270";
           break;
         case 0x0826:
-          os << "HD Webcam C525";
+          productStr = "HD Webcam C525";
           break;
         case 0x0828:
-          os << "HD Webcam B990";
+          productStr = "HD Webcam B990";
           break;
         case 0x082b:
-          os << "Webcam C170";
+          productStr = "Webcam C170";
           break;
         case 0x082d:
-          os << "HD Pro Webcam C920";
+          productStr = "HD Pro Webcam C920";
           break;
         case 0x0836:
-          os << "B525 HD Webcam";
+          productStr = "B525 HD Webcam";
           break;
         case 0x0843:
-          os << "Webcam C930e";
+          productStr = "Webcam C930e";
           break;
       }
-      break;
+      return fmt::format("Logitech, Inc. {}", productStr);
+    }
   }
 
-  return os.str();
+  return {};
 }
 
 int CheckedIoctl(int fd, unsigned long req, void* data,  // NOLINT(runtime/int)
                  const char* name, const char* file, int line, bool quiet) {
   int retval = ioctl(fd, req, data);
   if (!quiet && retval < 0) {
-    wpi::SmallString<64> localfile{file};
-    localfile.push_back('\0');
-    WPI_ERROR(Instance::GetInstance().logger,
-              "ioctl " << name << " failed at " << basename(localfile.data())
-                       << ":" << line << ": " << std::strerror(errno));
+    WPI_ERROR(Instance::GetInstance().logger, "ioctl {} failed at {}:{}: {}",
+              name, fs::path{file}.filename().string(), line,
+              std::strerror(errno));
   }
   return retval;
 }
diff --git a/cscore/src/main/native/linux/UsbUtil.h b/cscore/src/main/native/linux/UsbUtil.h
index 3d038a8bfb..9f6f8f5376 100644
--- a/cscore/src/main/native/linux/UsbUtil.h
+++ b/cscore/src/main/native/linux/UsbUtil.h
@@ -5,15 +5,11 @@
 #ifndef CSCORE_USBUTIL_H_
 #define CSCORE_USBUTIL_H_
 
-#include <stdint.h>
-
-#include <wpi/SmallVector.h>
-#include <wpi/StringRef.h>
+#include <string>
 
 namespace cs {
 
-wpi::StringRef GetUsbNameFromId(int vendor, int product,
-                                wpi::SmallVectorImpl<char>& buf);
+std::string GetUsbNameFromId(int vendor, int product);
 
 int CheckedIoctl(int fd, unsigned long req, void* data,  // NOLINT(runtime/int)
                  const char* name, const char* file, int line, bool quiet);
diff --git a/cscore/src/main/native/osx/UsbCameraImpl.cpp b/cscore/src/main/native/osx/UsbCameraImpl.cpp
index ab491426d1..3b5d82185c 100644
--- a/cscore/src/main/native/osx/UsbCameraImpl.cpp
+++ b/cscore/src/main/native/osx/UsbCameraImpl.cpp
@@ -6,19 +6,19 @@
 
 namespace cs {
 
-CS_Source CreateUsbCameraDev(const wpi::Twine& name, int dev,
+CS_Source CreateUsbCameraDev(std::string_view name, int dev,
                              CS_Status* status) {
   *status = CS_INVALID_HANDLE;
   return 0;
 }
 
-CS_Source CreateUsbCameraPath(const wpi::Twine& name, const wpi::Twine& path,
+CS_Source CreateUsbCameraPath(std::string_view name, std::string_view path,
                               CS_Status* status) {
   *status = CS_INVALID_HANDLE;
   return 0;
 }
 
-void SetUsbCameraPath(CS_Source source, const wpi::Twine& path,
+void SetUsbCameraPath(CS_Source source, std::string_view path,
                       CS_Status* status) {
   *status = CS_INVALID_HANDLE;
 }
diff --git a/cscore/src/main/native/windows/UsbCameraImpl.cpp b/cscore/src/main/native/windows/UsbCameraImpl.cpp
index 10ce8d982a..082057ccc7 100644
--- a/cscore/src/main/native/windows/UsbCameraImpl.cpp
+++ b/cscore/src/main/native/windows/UsbCameraImpl.cpp
@@ -26,8 +26,7 @@
 #include <opencv2/highgui/highgui.hpp>
 #include <opencv2/imgproc/imgproc.hpp>
 #include <wpi/MemAlloc.h>
-#include <wpi/SmallString.h>
-#include <wpi/raw_ostream.h>
+#include <wpi/StringExtras.h>
 #include <wpi/timestamp.h>
 
 #include "COMCreators.h"
@@ -69,17 +68,17 @@ using namespace cs;
 
 namespace cs {
 
-UsbCameraImpl::UsbCameraImpl(const wpi::Twine& name, wpi::Logger& logger,
+UsbCameraImpl::UsbCameraImpl(std::string_view name, wpi::Logger& logger,
                              Notifier& notifier, Telemetry& telemetry,
-                             const wpi::Twine& path)
-    : SourceImpl{name, logger, notifier, telemetry}, m_path{path.str()} {
+                             std::string_view path)
+    : SourceImpl{name, logger, notifier, telemetry}, m_path{path} {
   std::wstring_convert<std::codecvt_utf8<wchar_t>> utf8_conv;
   m_widePath = utf8_conv.from_bytes(m_path.c_str());
   m_deviceId = -1;
   StartMessagePump();
 }
 
-UsbCameraImpl::UsbCameraImpl(const wpi::Twine& name, wpi::Logger& logger,
+UsbCameraImpl::UsbCameraImpl(std::string_view name, wpi::Logger& logger,
                              Notifier& notifier, Telemetry& telemetry,
                              int deviceId)
     : SourceImpl{name, logger, notifier, telemetry}, m_deviceId(deviceId) {
@@ -99,11 +98,11 @@ void UsbCameraImpl::SetProperty(int property, int value, CS_Status* status) {
           SetCameraMessage, msg.kind, &msg);
   *status = result;
 }
-void UsbCameraImpl::SetStringProperty(int property, const wpi::Twine& value,
+void UsbCameraImpl::SetStringProperty(int property, std::string_view value,
                                       CS_Status* status) {
   Message msg{Message::kCmdSetPropertyStr};
   msg.data[0] = property;
-  msg.dataStr = value.str();
+  msg.dataStr = value;
   auto result =
       m_messagePump->SendWindowMessage<CS_Status, Message::Kind, Message*>(
           SetCameraMessage, msg.kind, &msg);
@@ -197,9 +196,9 @@ void UsbCameraImpl::NumSinksEnabledChanged() {
       SetCameraMessage, Message::kNumSinksEnabledChanged, nullptr);
 }
 
-void UsbCameraImpl::SetPath(const wpi::Twine& path, CS_Status* status) {
+void UsbCameraImpl::SetPath(std::string_view path, CS_Status* status) {
   Message msg{Message::kCmdSetPath};
-  msg.dataStr = path.str();
+  msg.dataStr = path;
   auto result =
       m_messagePump->SendWindowMessage<CS_Status, Message::Kind, Message*>(
           SetCameraMessage, msg.kind, &msg);
@@ -257,7 +256,7 @@ bool UsbCameraImpl::CheckDeviceChange(WPARAM wParam, DEV_BROADCAST_HDR* pHdr,
 
 void UsbCameraImpl::DeviceDisconnect() {
   if (m_connectVerbose)
-    SINFO("Disconnected from " << m_path);
+    SINFO("Disconnected from {}", m_path);
   m_sourceReader.Reset();
   m_mediaSource.Reset();
   if (m_imageCallback) {
@@ -268,8 +267,8 @@ void UsbCameraImpl::DeviceDisconnect() {
   SetConnected(false);
 }
 
-static bool IsPercentageProperty(wpi::StringRef name) {
-  if (name.startswith("raw_"))
+static bool IsPercentageProperty(std::string_view name) {
+  if (wpi::starts_with(name, "raw_"))
     name = name.substr(4);
   return name == "Brightness" || name == "Contrast" || name == "Saturation" ||
          name == "Hue" || name == "Sharpness" || name == "Gain" ||
@@ -341,8 +340,7 @@ void UsbCameraImpl::ProcessFrame(IMFSample* videoSample,
     case cs::VideoMode::PixelFormat::kMJPEG: {
       // Special case
       PutFrame(VideoMode::kMJPEG, mode.width, mode.height,
-               wpi::StringRef(reinterpret_cast<char*>(ptr), length),
-               wpi::Now());
+               {reinterpret_cast<char*>(ptr), length}, wpi::Now());
       doFinalSet = false;
       break;
     }
@@ -477,9 +475,9 @@ bool UsbCameraImpl::DeviceConnect() {
     return true;
 
   if (m_connectVerbose)
-    SINFO("Connecting to USB camera on " << m_path);
+    SINFO("Connecting to USB camera on {}", m_path);
 
-  SDEBUG3("opening device");
+  SDEBUG3("{}", "opening device");
 
   const wchar_t* path = m_widePath.c_str();
   m_mediaSource = CreateVideoCaptureDevice(path);
@@ -506,13 +504,13 @@ bool UsbCameraImpl::DeviceConnect() {
   }
 
   if (!m_properties_cached) {
-    SDEBUG3("caching properties");
+    SDEBUG3("{}", "caching properties");
     DeviceCacheProperties();
     DeviceCacheVideoModes();
     DeviceCacheMode();
     m_properties_cached = true;
   } else {
-    SDEBUG3("restoring video mode");
+    SDEBUG3("{}", "restoring video mode");
     DeviceSetMode();
   }
 
@@ -526,7 +524,7 @@ bool UsbCameraImpl::DeviceConnect() {
 }
 
 std::unique_ptr<PropertyImpl> UsbCameraImpl::CreateEmptyProperty(
-    const wpi::Twine& name) const {
+    std::string_view name) const {
   return nullptr;
 }
 
@@ -545,7 +543,7 @@ bool UsbCameraImpl::CacheProperties(CS_Status* status) const {
 }
 
 template <typename TagProperty, typename IAM>
-void UsbCameraImpl::DeviceAddProperty(const wpi::Twine& name_, TagProperty tag,
+void UsbCameraImpl::DeviceAddProperty(std::string_view name_, TagProperty tag,
                                       IAM* pProcAmp) {
   // First see if properties exist
   bool isValid = false;
@@ -556,11 +554,11 @@ void UsbCameraImpl::DeviceAddProperty(const wpi::Twine& name_, TagProperty tag,
   }
 }
 
-template void UsbCameraImpl::DeviceAddProperty(const wpi::Twine& name_,
+template void UsbCameraImpl::DeviceAddProperty(std::string_view name_,
                                                tagVideoProcAmpProperty tag,
                                                IAMVideoProcAmp* pProcAmp);
 
-template void UsbCameraImpl::DeviceAddProperty(const wpi::Twine& name_,
+template void UsbCameraImpl::DeviceAddProperty(std::string_view name_,
                                                tagCameraControlProperty tag,
                                                IAMCameraControl* pProcAmp);
 
@@ -669,7 +667,7 @@ void UsbCameraImpl::DeviceCacheProperty(
   } else {
     // Read current raw value and set percentage from it
     if (!rawProp->DeviceGet(lock, pProcAmp))
-      SWARNING("failed to get property " << rawProp->name);
+      SWARNING("failed to get property {}", rawProp->name);
 
     if (perProp) {
       perProp->SetValue(RawToPercentage(*rawProp, rawProp->value));
@@ -680,7 +678,7 @@ void UsbCameraImpl::DeviceCacheProperty(
   // Set value on device if user-configured
   if (rawProp->valueSet) {
     if (!rawProp->DeviceSet(lock, pProcAmp))
-      SWARNING("failed to set property " << rawProp->name);
+      SWARNING("failed to set property {}", rawProp->name);
   }
 
   // Update pointers since we released the lock
@@ -764,7 +762,7 @@ CS_StatusValue UsbCameraImpl::DeviceCmdSetProperty(
   bool setString = (msg.kind == Message::kCmdSetPropertyStr);
   int property = msg.data[0];
   int value = msg.data[1];
-  wpi::StringRef valueStr = msg.dataStr;
+  std::string_view valueStr = msg.dataStr;
 
   // Look up
   auto prop = static_cast<UsbCameraProperty*>(GetProperty(property));
@@ -1022,23 +1020,21 @@ void UsbCameraImpl::DeviceCacheVideoModes() {
   m_notifier.NotifySource(*this, CS_SOURCE_VIDEOMODES_UPDATED);
 }
 
-static void ParseVidAndPid(wpi::StringRef path, int* pid, int* vid) {
-  auto vidIndex = path.find_lower("vid_");
-  auto pidIndex = path.find_lower("pid_");
+static void ParseVidAndPid(std::string_view path, int* pid, int* vid) {
+  auto vidIndex = wpi::find_lower(path, "vid_");
+  auto pidIndex = wpi::find_lower(path, "pid_");
 
-  if (vidIndex != wpi::StringRef::npos) {
-    auto vidSlice = path.slice(vidIndex + 4, vidIndex + 8);
-    uint16_t val = 0;
-    if (!vidSlice.getAsInteger(16, val)) {
-      *vid = val;
+  if (vidIndex != std::string_view::npos) {
+    auto vidSlice = wpi::slice(path, vidIndex + 4, vidIndex + 8);
+    if (auto v = wpi::parse_integer<uint16_t>(vidSlice, 16)) {
+      *vid = v.value();
     }
   }
 
-  if (pidIndex != wpi::StringRef::npos) {
-    auto pidSlice = path.slice(pidIndex + 4, pidIndex + 8);
-    uint16_t val = 0;
-    if (!pidSlice.getAsInteger(16, val)) {
-      *pid = val;
+  if (pidIndex != std::string_view::npos) {
+    auto pidSlice = wpi::slice(path, pidIndex + 4, pidIndex + 8);
+    if (auto v = wpi::parse_integer<uint16_t>(pidSlice, 16)) {
+      *pid = v.value();
     }
   }
 }
@@ -1112,7 +1108,7 @@ done:
   return retval;
 }
 
-CS_Source CreateUsbCameraDev(const wpi::Twine& name, int dev,
+CS_Source CreateUsbCameraDev(std::string_view name, int dev,
                              CS_Status* status) {
   // First check if device exists
   auto devices = cs::EnumerateUsbCameras(status);
@@ -1125,7 +1121,7 @@ CS_Source CreateUsbCameraDev(const wpi::Twine& name, int dev,
   return inst.CreateSource(CS_SOURCE_USB, source);
 }
 
-CS_Source CreateUsbCameraPath(const wpi::Twine& name, const wpi::Twine& path,
+CS_Source CreateUsbCameraPath(std::string_view name, std::string_view path,
                               CS_Status* status) {
   auto& inst = Instance::GetInstance();
   auto source = std::make_shared<UsbCameraImpl>(
@@ -1133,7 +1129,7 @@ CS_Source CreateUsbCameraPath(const wpi::Twine& name, const wpi::Twine& path,
   return inst.CreateSource(CS_SOURCE_USB, source);
 }
 
-void SetUsbCameraPath(CS_Source source, const wpi::Twine& path,
+void SetUsbCameraPath(CS_Source source, std::string_view path,
                       CS_Status* status) {
   auto data = Instance::GetInstance().GetSource(source);
   if (!data || data->kind != CS_SOURCE_USB) {
diff --git a/cscore/src/main/native/windows/UsbCameraImpl.h b/cscore/src/main/native/windows/UsbCameraImpl.h
index 285da2c16b..05ee359bfc 100644
--- a/cscore/src/main/native/windows/UsbCameraImpl.h
+++ b/cscore/src/main/native/windows/UsbCameraImpl.h
@@ -16,6 +16,7 @@
 #include <atomic>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <thread>
 #include <utility>
 #include <vector>
@@ -23,7 +24,6 @@
 #include <Dbt.h>
 #include <wpi/STLExtras.h>
 #include <wpi/SmallVector.h>
-#include <wpi/Twine.h>
 #include <wpi/condition_variable.h>
 #include <wpi/mutex.h>
 #include <wpi/raw_istream.h>
@@ -40,9 +40,9 @@ namespace cs {
 class UsbCameraImpl : public SourceImpl,
                       public std::enable_shared_from_this<UsbCameraImpl> {
  public:
-  UsbCameraImpl(const wpi::Twine& name, wpi::Logger& logger, Notifier& notifier,
-                Telemetry& telemetry, const wpi::Twine& path);
-  UsbCameraImpl(const wpi::Twine& name, wpi::Logger& logger, Notifier& notifier,
+  UsbCameraImpl(std::string_view name, wpi::Logger& logger, Notifier& notifier,
+                Telemetry& telemetry, std::string_view path);
+  UsbCameraImpl(std::string_view name, wpi::Logger& logger, Notifier& notifier,
                 Telemetry& telemetry, int deviceId);
   ~UsbCameraImpl() override;
 
@@ -50,7 +50,7 @@ class UsbCameraImpl : public SourceImpl,
 
   // Property functions
   void SetProperty(int property, int value, CS_Status* status) override;
-  void SetStringProperty(int property, const wpi::Twine& value,
+  void SetStringProperty(int property, std::string_view value,
                          CS_Status* status) override;
 
   // Standard common camera properties
@@ -75,7 +75,7 @@ class UsbCameraImpl : public SourceImpl,
   void ProcessFrame(IMFSample* sample, const VideoMode& mode);
   void PostRequestNewFrame();
 
-  void SetPath(const wpi::Twine& path, CS_Status* status);
+  void SetPath(std::string_view path, CS_Status* status);
   std::string GetPath() const;
 
   // Messages passed to/from camera thread
@@ -107,7 +107,7 @@ class UsbCameraImpl : public SourceImpl,
 
  protected:
   std::unique_ptr<PropertyImpl> CreateEmptyProperty(
-      const wpi::Twine& name) const override;
+      std::string_view name) const override;
 
   // Cache properties.  Immediately successful if properties are already cached.
   // If they are not, tries to connect to the camera to do so; returns false and
@@ -132,7 +132,7 @@ class UsbCameraImpl : public SourceImpl,
   void DeviceCacheProperties();
   void DeviceCacheVideoModes();
   template <typename TagProperty, typename IAM>
-  void DeviceAddProperty(const wpi::Twine& name_, TagProperty tag,
+  void DeviceAddProperty(std::string_view name_, TagProperty tag,
                          IAM* pProcAmp);
 
   ComPtr<IMFMediaType> DeviceCheckModeValid(const VideoMode& toCheck);
diff --git a/cscore/src/main/native/windows/UsbCameraProperty.cpp b/cscore/src/main/native/windows/UsbCameraProperty.cpp
index ebd8967e48..5ddeebf8cd 100644
--- a/cscore/src/main/native/windows/UsbCameraProperty.cpp
+++ b/cscore/src/main/native/windows/UsbCameraProperty.cpp
@@ -4,14 +4,16 @@
 
 #include "UsbCameraProperty.h"
 
+#include <fmt/format.h>
+
 #include "ComPtr.h"
 
 using namespace cs;
 
-UsbCameraProperty::UsbCameraProperty(const wpi::Twine& name_,
+UsbCameraProperty::UsbCameraProperty(std::string_view name_,
                                      tagVideoProcAmpProperty tag, bool autoProp,
                                      IAMVideoProcAmp* pProcAmp, bool* isValid)
-    : PropertyImpl{autoProp ? name_ + "_auto" : name_} {
+    : PropertyImpl{autoProp ? fmt::format("{}_auto", name_) : name_} {
   this->tagVideoProc = tag;
   this->isControlProperty = false;
   this->isAutoProp = autoProp;
@@ -71,11 +73,11 @@ bool UsbCameraProperty::DeviceSet(std::unique_lock<wpi::mutex>& lock,
   return false;
 }
 
-UsbCameraProperty::UsbCameraProperty(const wpi::Twine& name_,
+UsbCameraProperty::UsbCameraProperty(std::string_view name_,
                                      tagCameraControlProperty tag,
                                      bool autoProp, IAMCameraControl* pProcAmp,
                                      bool* isValid)
-    : PropertyImpl{autoProp ? name_ + "_auto" : name_} {
+    : PropertyImpl{autoProp ? fmt::format("{}_auto", name_) : name_} {
   this->tagCameraControl = tag;
   this->isControlProperty = true;
   this->isAutoProp = autoProp;
diff --git a/cscore/src/main/native/windows/UsbCameraProperty.h b/cscore/src/main/native/windows/UsbCameraProperty.h
index 7dc52f120d..03cd375393 100644
--- a/cscore/src/main/native/windows/UsbCameraProperty.h
+++ b/cscore/src/main/native/windows/UsbCameraProperty.h
@@ -9,6 +9,7 @@
 #include <mfreadwrite.h>
 
 #include <memory>
+#include <string_view>
 
 #include <Dshow.h>
 #include <wpi/mutex.h>
@@ -21,19 +22,19 @@ namespace cs {
 class UsbCameraProperty : public PropertyImpl {
  public:
   UsbCameraProperty() = default;
-  explicit UsbCameraProperty(const wpi::Twine& name_) : PropertyImpl{name_} {}
+  explicit UsbCameraProperty(std::string_view name_) : PropertyImpl{name_} {}
 
   // Software property constructor
-  UsbCameraProperty(const wpi::Twine& name_, unsigned id_,
-                    CS_PropertyKind kind_, int minimum_, int maximum_,
-                    int step_, int defaultValue_, int value_)
+  UsbCameraProperty(std::string_view name_, unsigned id_, CS_PropertyKind kind_,
+                    int minimum_, int maximum_, int step_, int defaultValue_,
+                    int value_)
       : PropertyImpl(name_, kind_, minimum_, maximum_, step_, defaultValue_,
                      value_),
         device{false},
         id{id_} {}
 
   // Normalized property constructor
-  UsbCameraProperty(const wpi::Twine& name_, int rawIndex_,
+  UsbCameraProperty(std::string_view name_, int rawIndex_,
                     const UsbCameraProperty& rawProp, int defaultValue_,
                     int value_)
       : PropertyImpl(name_, rawProp.propKind, 1, defaultValue_, value_),
@@ -47,10 +48,10 @@ class UsbCameraProperty : public PropertyImpl {
     maximum = 100;
   }
 
-  UsbCameraProperty(const wpi::Twine& name_, tagVideoProcAmpProperty tag,
+  UsbCameraProperty(std::string_view name_, tagVideoProcAmpProperty tag,
                     bool autoProp, IAMVideoProcAmp* pProcAmp, bool* isValid);
 
-  UsbCameraProperty(const wpi::Twine& name_, tagCameraControlProperty tag,
+  UsbCameraProperty(std::string_view name_, tagCameraControlProperty tag,
                     bool autoProp, IAMCameraControl* pProcAmp, bool* isValid);
 
   bool DeviceGet(std::unique_lock<wpi::mutex>& lock,
diff --git a/glass/.styleguide b/glass/.styleguide
index cf7a487147..d555d5af8a 100644
--- a/glass/.styleguide
+++ b/glass/.styleguide
@@ -21,6 +21,7 @@ repoRootNameOverride {
 includeOtherLibs {
   ^GLFW
   ^cscore
+  ^fmt/
   ^frc/
   ^imgui
   ^ntcore
diff --git a/glass/src/app/native/cpp/main.cpp b/glass/src/app/native/cpp/main.cpp
index 62821538bf..3e0adf197d 100644
--- a/glass/src/app/native/cpp/main.cpp
+++ b/glass/src/app/native/cpp/main.cpp
@@ -5,9 +5,9 @@
 #include <memory>
 
 #include <GLFW/glfw3.h>
+#include <fmt/format.h>
 #include <imgui.h>
 #include <ntcore_cpp.h>
-#include <wpi/SmallString.h>
 #include <wpigui.h>
 
 #include "glass/Context.h"
@@ -24,13 +24,13 @@ namespace gui = wpi::gui;
 const char* GetWPILibVersion();
 
 namespace glass {
-wpi::StringRef GetResource_glass_16_png();
-wpi::StringRef GetResource_glass_32_png();
-wpi::StringRef GetResource_glass_48_png();
-wpi::StringRef GetResource_glass_64_png();
-wpi::StringRef GetResource_glass_128_png();
-wpi::StringRef GetResource_glass_256_png();
-wpi::StringRef GetResource_glass_512_png();
+std::string_view GetResource_glass_16_png();
+std::string_view GetResource_glass_32_png();
+std::string_view GetResource_glass_48_png();
+std::string_view GetResource_glass_64_png();
+std::string_view GetResource_glass_128_png();
+std::string_view GetResource_glass_256_png();
+std::string_view GetResource_glass_512_png();
 }  // namespace glass
 
 static std::unique_ptr<glass::PlotProvider> gPlotProvider;
@@ -56,11 +56,9 @@ static void NtInitialize() {
     bool timedOut;
     for (auto&& event : nt::PollConnectionListener(poller, 0, &timedOut)) {
       if (event.connected) {
-        wpi::SmallString<64> title;
-        title = "Glass - Connected (";
-        title += event.conn.remote_ip;
-        title += ')';
-        glfwSetWindowTitle(win, title.c_str());
+        glfwSetWindowTitle(
+            win, fmt::format("Glass - Connected ({})", event.conn.remote_ip)
+                     .c_str());
       } else {
         glfwSetWindowTitle(win, "Glass - DISCONNECTED");
       }
@@ -81,9 +79,8 @@ static void NtInitialize() {
       } else if (msg.level >= NT_LOG_WARNING) {
         level = "WARNING: ";
       }
-      gNetworkTablesLog.Append(
-          wpi::Twine{level} + msg.message + wpi::Twine{" ("} + msg.filename +
-          wpi::Twine{':'} + wpi::Twine{msg.line} + wpi::Twine{")\n"});
+      gNetworkTablesLog.Append(fmt::format("{}{} ({}:{})\n", level, msg.message,
+                                           msg.filename, msg.line));
     }
   });
 
diff --git a/glass/src/lib/native/cpp/Context.cpp b/glass/src/lib/native/cpp/Context.cpp
index 031170fbe5..936acb2d95 100644
--- a/glass/src/lib/native/cpp/Context.cpp
+++ b/glass/src/lib/native/cpp/Context.cpp
@@ -11,7 +11,7 @@
 #include <imgui.h>
 #include <imgui_internal.h>
 #include <imgui_stdlib.h>
-#include <wpi/StringRef.h>
+#include <wpi/StringExtras.h>
 #include <wpi/timestamp.h>
 #include <wpigui.h>
 
@@ -23,64 +23,47 @@ Context* glass::gContext;
 
 static bool ConvertInt(Storage::Value* value) {
   value->type = Storage::Value::kInt;
-  if (value->stringVal.empty()) {
-    return false;
-  } else {
-    if (wpi::StringRef{value->stringVal}.getAsInteger(10, value->intVal)) {
-      return false;
-    }
+  if (auto val = wpi::parse_integer<int>(value->stringVal, 10)) {
+    value->intVal = val.value();
+    return true;
   }
-  return true;
+  return false;
 }
 
 static bool ConvertInt64(Storage::Value* value) {
   value->type = Storage::Value::kInt64;
-  if (value->stringVal.empty()) {
-    return false;
-  } else {
-    if (wpi::StringRef{value->stringVal}.getAsInteger(10, value->int64Val)) {
-      return false;
-    }
+  if (auto val = wpi::parse_integer<int64_t>(value->stringVal, 10)) {
+    value->int64Val = val.value();
+    return true;
   }
-  return true;
+  return false;
 }
 
 static bool ConvertBool(Storage::Value* value) {
   value->type = Storage::Value::kBool;
-  if (value->stringVal.empty()) {
-    return false;
-  } else {
-    int val;
-    if (wpi::StringRef{value->stringVal}.getAsInteger(10, val)) {
-      return false;
-    }
-    value->boolVal = (val != 0);
+  if (auto val = wpi::parse_integer<int>(value->stringVal, 10)) {
+    value->intVal = (val.value() != 0);
+    return true;
   }
-  return true;
+  return false;
 }
 
 static bool ConvertFloat(Storage::Value* value) {
   value->type = Storage::Value::kFloat;
-  if (value->stringVal.empty()) {
-    return false;
-  } else {
-    if (std::sscanf(value->stringVal.c_str(), "%f", &value->floatVal) != 1) {
-      return false;
-    }
+  if (auto val = wpi::parse_float<float>(value->stringVal)) {
+    value->floatVal = val.value();
+    return true;
   }
-  return true;
+  return false;
 }
 
 static bool ConvertDouble(Storage::Value* value) {
   value->type = Storage::Value::kDouble;
-  if (value->stringVal.empty()) {
-    return false;
-  } else {
-    if (std::sscanf(value->stringVal.c_str(), "%lf", &value->doubleVal) != 1) {
-      return false;
-    }
+  if (auto val = wpi::parse_float<double>(value->stringVal)) {
+    value->doubleVal = val.value();
+    return true;
   }
-  return true;
+  return false;
 }
 
 static void* GlassStorageReadOpen(ImGuiContext*, ImGuiSettingsHandler* handler,
@@ -96,7 +79,7 @@ static void* GlassStorageReadOpen(ImGuiContext*, ImGuiSettingsHandler* handler,
 static void GlassStorageReadLine(ImGuiContext*, ImGuiSettingsHandler*,
                                  void* entry, const char* line) {
   auto storage = static_cast<Storage*>(entry);
-  auto [key, val] = wpi::StringRef{line}.split('=');
+  auto [key, val] = wpi::split(line, '=');
   auto& keys = storage->GetKeys();
   auto& values = storage->GetValues();
   auto it = std::find(keys.begin(), keys.end(), key);
@@ -144,7 +127,8 @@ static void GlassStorageWriteAll(ImGuiContext*, ImGuiSettingsHandler* handler,
   for (auto&& entryIt : sorted) {
     auto& entry = *entryIt;
     out_buf->append("[GlassStorage][");
-    out_buf->append(entry.first().begin(), entry.first().end());
+    out_buf->append(entry.first().data(),
+                    entry.first().data() + entry.first().size());
     out_buf->append("]\n");
     auto& keys = entry.second->GetKeys();
     auto& values = entry.second->GetValues();
@@ -233,7 +217,7 @@ uint64_t glass::GetZeroTime() {
   return gContext->zeroTime;
 }
 
-Storage::Value& Storage::GetValue(wpi::StringRef key) {
+Storage::Value& Storage::GetValue(std::string_view key) {
   auto it = std::find(m_keys.begin(), m_keys.end(), key);
   if (it == m_keys.end()) {
     m_keys.emplace_back(key);
@@ -244,49 +228,49 @@ Storage::Value& Storage::GetValue(wpi::StringRef key) {
   }
 }
 
-#define DEFUN(CapsName, LowerName, CType)                                    \
-  CType Storage::Get##CapsName(wpi::StringRef key, CType defaultVal) const { \
-    auto it = std::find(m_keys.begin(), m_keys.end(), key);                  \
-    if (it == m_keys.end())                                                  \
-      return defaultVal;                                                     \
-    Value& value = *m_values[it - m_keys.begin()];                           \
-    if (value.type != Value::k##CapsName) {                                  \
-      if (!Convert##CapsName(&value))                                        \
-        value.LowerName##Val = defaultVal;                                   \
-    }                                                                        \
-    return value.LowerName##Val;                                             \
-  }                                                                          \
-                                                                             \
-  void Storage::Set##CapsName(wpi::StringRef key, CType val) {               \
-    auto it = std::find(m_keys.begin(), m_keys.end(), key);                  \
-    if (it == m_keys.end()) {                                                \
-      m_keys.emplace_back(key);                                              \
-      m_values.emplace_back(std::make_unique<Value>());                      \
-      m_values.back()->type = Value::k##CapsName;                            \
-      m_values.back()->LowerName##Val = val;                                 \
-    } else {                                                                 \
-      Value& value = *m_values[it - m_keys.begin()];                         \
-      value.type = Value::k##CapsName;                                       \
-      value.LowerName##Val = val;                                            \
-    }                                                                        \
-  }                                                                          \
-                                                                             \
-  CType* Storage::Get##CapsName##Ref(wpi::StringRef key, CType defaultVal) { \
-    auto it = std::find(m_keys.begin(), m_keys.end(), key);                  \
-    if (it == m_keys.end()) {                                                \
-      m_keys.emplace_back(key);                                              \
-      m_values.emplace_back(std::make_unique<Value>());                      \
-      m_values.back()->type = Value::k##CapsName;                            \
-      m_values.back()->LowerName##Val = defaultVal;                          \
-      return &m_values.back()->LowerName##Val;                               \
-    } else {                                                                 \
-      Value& value = *m_values[it - m_keys.begin()];                         \
-      if (value.type != Value::k##CapsName) {                                \
-        if (!Convert##CapsName(&value))                                      \
-          value.LowerName##Val = defaultVal;                                 \
-      }                                                                      \
-      return &value.LowerName##Val;                                          \
-    }                                                                        \
+#define DEFUN(CapsName, LowerName, CType)                                      \
+  CType Storage::Get##CapsName(std::string_view key, CType defaultVal) const { \
+    auto it = std::find(m_keys.begin(), m_keys.end(), key);                    \
+    if (it == m_keys.end())                                                    \
+      return defaultVal;                                                       \
+    Value& value = *m_values[it - m_keys.begin()];                             \
+    if (value.type != Value::k##CapsName) {                                    \
+      if (!Convert##CapsName(&value))                                          \
+        value.LowerName##Val = defaultVal;                                     \
+    }                                                                          \
+    return value.LowerName##Val;                                               \
+  }                                                                            \
+                                                                               \
+  void Storage::Set##CapsName(std::string_view key, CType val) {               \
+    auto it = std::find(m_keys.begin(), m_keys.end(), key);                    \
+    if (it == m_keys.end()) {                                                  \
+      m_keys.emplace_back(key);                                                \
+      m_values.emplace_back(std::make_unique<Value>());                        \
+      m_values.back()->type = Value::k##CapsName;                              \
+      m_values.back()->LowerName##Val = val;                                   \
+    } else {                                                                   \
+      Value& value = *m_values[it - m_keys.begin()];                           \
+      value.type = Value::k##CapsName;                                         \
+      value.LowerName##Val = val;                                              \
+    }                                                                          \
+  }                                                                            \
+                                                                               \
+  CType* Storage::Get##CapsName##Ref(std::string_view key, CType defaultVal) { \
+    auto it = std::find(m_keys.begin(), m_keys.end(), key);                    \
+    if (it == m_keys.end()) {                                                  \
+      m_keys.emplace_back(key);                                                \
+      m_values.emplace_back(std::make_unique<Value>());                        \
+      m_values.back()->type = Value::k##CapsName;                              \
+      m_values.back()->LowerName##Val = defaultVal;                            \
+      return &m_values.back()->LowerName##Val;                                 \
+    } else {                                                                   \
+      Value& value = *m_values[it - m_keys.begin()];                           \
+      if (value.type != Value::k##CapsName) {                                  \
+        if (!Convert##CapsName(&value))                                        \
+          value.LowerName##Val = defaultVal;                                   \
+      }                                                                        \
+      return &value.LowerName##Val;                                            \
+    }                                                                          \
   }
 
 DEFUN(Int, int, int)
@@ -295,18 +279,18 @@ DEFUN(Bool, bool, bool)
 DEFUN(Float, float, float)
 DEFUN(Double, double, double)
 
-std::string Storage::GetString(wpi::StringRef key,
-                               const std::string& defaultVal) const {
+std::string Storage::GetString(std::string_view key,
+                               std::string_view defaultVal) const {
   auto it = std::find(m_keys.begin(), m_keys.end(), key);
   if (it == m_keys.end()) {
-    return defaultVal;
+    return std::string{defaultVal};
   }
   Value& value = *m_values[it - m_keys.begin()];
   value.type = Value::kString;
   return value.stringVal;
 }
 
-void Storage::SetString(wpi::StringRef key, const wpi::Twine& val) {
+void Storage::SetString(std::string_view key, std::string_view val) {
   auto it = std::find(m_keys.begin(), m_keys.end(), key);
   if (it == m_keys.end()) {
     m_keys.emplace_back(key);
@@ -315,12 +299,12 @@ void Storage::SetString(wpi::StringRef key, const wpi::Twine& val) {
   } else {
     Value& value = *m_values[it - m_keys.begin()];
     value.type = Value::kString;
-    value.stringVal = val.str();
+    value.stringVal = val;
   }
 }
 
-std::string* Storage::GetStringRef(wpi::StringRef key,
-                                   wpi::StringRef defaultVal) {
+std::string* Storage::GetStringRef(std::string_view key,
+                                   std::string_view defaultVal) {
   auto it = std::find(m_keys.begin(), m_keys.end(), key);
   if (it == m_keys.end()) {
     m_keys.emplace_back(key);
@@ -342,7 +326,7 @@ Storage& glass::GetStorage() {
   return *storage;
 }
 
-Storage& glass::GetStorage(wpi::StringRef id) {
+Storage& glass::GetStorage(std::string_view id) {
   auto& storage = gContext->storage[id];
   if (!storage) {
     storage = std::make_unique<Storage>();
@@ -350,10 +334,10 @@ Storage& glass::GetStorage(wpi::StringRef id) {
   return *storage;
 }
 
-static void PushIDStack(wpi::StringRef label_id) {
+static void PushIDStack(std::string_view label_id) {
   gContext->idStack.emplace_back(gContext->curId.size());
 
-  auto [label, id] = wpi::StringRef{label_id}.split("###");
+  auto [label, id] = wpi::split(label_id, "###");
   // if no ###id, use label as id
   if (id.empty()) {
     id = label;
@@ -392,7 +376,7 @@ void glass::EndChild() {
 
 bool glass::CollapsingHeader(const char* label, ImGuiTreeNodeFlags flags) {
   wpi::SmallString<64> openKey;
-  auto [name, id] = wpi::StringRef{label}.split("###");
+  auto [name, id] = wpi::split(label, "###");
   // if no ###id, use name as id
   if (id.empty()) {
     id = name;
@@ -400,7 +384,7 @@ bool glass::CollapsingHeader(const char* label, ImGuiTreeNodeFlags flags) {
   openKey = id;
   openKey += "###open";
 
-  bool* open = GetStorage().GetBoolRef(openKey);
+  bool* open = GetStorage().GetBoolRef(openKey.str());
   *open = ImGui::CollapsingHeader(
       label, flags | (*open ? ImGuiTreeNodeFlags_DefaultOpen : 0));
   return *open;
@@ -428,7 +412,7 @@ void glass::PushID(const char* str_id) {
 }
 
 void glass::PushID(const char* str_id_begin, const char* str_id_end) {
-  PushIDStack(wpi::StringRef(str_id_begin, str_id_end - str_id_begin));
+  PushIDStack(std::string_view(str_id_begin, str_id_end - str_id_begin));
   ImGui::PushID(str_id_begin, str_id_end);
 }
 
diff --git a/glass/src/lib/native/cpp/DataSource.cpp b/glass/src/lib/native/cpp/DataSource.cpp
index ab304fe63d..adab6e75a3 100644
--- a/glass/src/lib/native/cpp/DataSource.cpp
+++ b/glass/src/lib/native/cpp/DataSource.cpp
@@ -4,13 +4,15 @@
 
 #include "glass/DataSource.h"
 
+#include <fmt/format.h>
+
 #include "glass/ContextInternal.h"
 
 using namespace glass;
 
 wpi::sig::Signal<const char*, DataSource*> DataSource::sourceCreated;
 
-DataSource::DataSource(const wpi::Twine& id) : m_id{id.str()} {
+DataSource::DataSource(std::string_view id) : m_id{id} {
   auto it = gContext->sources.try_emplace(m_id, this);
   auto& srcName = it.first->getValue();
   m_name = srcName.name.get();
@@ -20,12 +22,11 @@ DataSource::DataSource(const wpi::Twine& id) : m_id{id.str()} {
   sourceCreated(m_id.c_str(), this);
 }
 
-DataSource::DataSource(const wpi::Twine& id, int index)
-    : DataSource{id + wpi::Twine('[') + wpi::Twine(index) + wpi::Twine(']')} {}
+DataSource::DataSource(std::string_view id, int index)
+    : DataSource{fmt::format("{}[{}]", id, index)} {}
 
-DataSource::DataSource(const wpi::Twine& id, int index, int index2)
-    : DataSource{id + wpi::Twine('[') + wpi::Twine(index) + wpi::Twine(',') +
-                 wpi::Twine(index2) + wpi::Twine(']')} {}
+DataSource::DataSource(std::string_view id, int index, int index2)
+    : DataSource{fmt::format("{}[{},{}]", id, index, index2)} {}
 
 DataSource::~DataSource() {
   if (!gContext) {
@@ -41,7 +42,7 @@ DataSource::~DataSource() {
   }
 }
 
-void DataSource::SetName(const wpi::Twine& name) {
+void DataSource::SetName(std::string_view name) {
   m_name->SetName(name);
 }
 
@@ -146,7 +147,7 @@ void DataSource::EmitDrag(ImGuiDragDropFlags flags) const {
   }
 }
 
-DataSource* DataSource::Find(wpi::StringRef id) {
+DataSource* DataSource::Find(std::string_view id) {
   auto it = gContext->sources.find(id);
   if (it == gContext->sources.end()) {
     return nullptr;
diff --git a/glass/src/lib/native/cpp/Window.cpp b/glass/src/lib/native/cpp/Window.cpp
index 83e59aa79f..5c014eb7b1 100644
--- a/glass/src/lib/native/cpp/Window.cpp
+++ b/glass/src/lib/native/cpp/Window.cpp
@@ -5,7 +5,7 @@
 #include "glass/Window.h"
 
 #include <imgui_internal.h>
-#include <wpi/StringRef.h>
+#include <wpi/StringExtras.h>
 
 #include "glass/Context.h"
 
@@ -86,26 +86,21 @@ void Window::ScaleDefault(float scale) {
   }
 }
 
-void Window::IniReadLine(const char* lineStr) {
-  wpi::StringRef line{lineStr};
-  auto [name, value] = line.split('=');
-  name = name.trim();
-  value = value.trim();
+void Window::IniReadLine(const char* line) {
+  auto [name, value] = wpi::split(line, '=');
+  name = wpi::trim(name);
+  value = wpi::trim(value);
 
   if (name == "name") {
     m_name = value;
   } else if (name == "visible") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      m_visible = num.value();
     }
-    m_visible = num;
   } else if (name == "enabled") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      m_enabled = num.value();
     }
-    m_enabled = num;
   }
 }
 
diff --git a/glass/src/lib/native/cpp/WindowManager.cpp b/glass/src/lib/native/cpp/WindowManager.cpp
index 8e7f971274..037b9bdd2b 100644
--- a/glass/src/lib/native/cpp/WindowManager.cpp
+++ b/glass/src/lib/native/cpp/WindowManager.cpp
@@ -5,14 +5,14 @@
 #include "glass/WindowManager.h"
 
 #include <algorithm>
+#include <cstdio>
 
-#include <wpi/StringRef.h>
-#include <wpi/raw_ostream.h>
+#include <fmt/format.h>
 #include <wpigui.h>
 
 using namespace glass;
 
-WindowManager::WindowManager(const wpi::Twine& iniName)
+WindowManager::WindowManager(std::string_view iniName)
     : m_iniSaver{iniName, this} {}
 
 // read/write open state to ini file
@@ -31,42 +31,42 @@ void WindowManager::IniSaver::IniWriteAll(ImGuiTextBuffer* out_buf) {
   }
 }
 
-Window* WindowManager::AddWindow(wpi::StringRef id,
+Window* WindowManager::AddWindow(std::string_view id,
                                  wpi::unique_function<void()> display) {
   auto win = GetOrAddWindow(id, false);
   if (!win) {
     return nullptr;
   }
   if (win->HasView()) {
-    wpi::errs() << "GUI: ignoring duplicate window '" << id << "'\n";
+    fmt::print(stderr, "GUI: ignoring duplicate window '{}'\n", id);
     return nullptr;
   }
   win->SetView(MakeFunctionView(std::move(display)));
   return win;
 }
 
-Window* WindowManager::AddWindow(wpi::StringRef id,
+Window* WindowManager::AddWindow(std::string_view id,
                                  std::unique_ptr<View> view) {
   auto win = GetOrAddWindow(id, false);
   if (!win) {
     return nullptr;
   }
   if (win->HasView()) {
-    wpi::errs() << "GUI: ignoring duplicate window '" << id << "'\n";
+    fmt::print(stderr, "GUI: ignoring duplicate window '{}'\n", id);
     return nullptr;
   }
   win->SetView(std::move(view));
   return win;
 }
 
-Window* WindowManager::GetOrAddWindow(wpi::StringRef id, bool duplicateOk) {
+Window* WindowManager::GetOrAddWindow(std::string_view id, bool duplicateOk) {
   // binary search
   auto it = std::lower_bound(
       m_windows.begin(), m_windows.end(), id,
-      [](const auto& elem, wpi::StringRef s) { return elem->GetId() < s; });
+      [](const auto& elem, std::string_view s) { return elem->GetId() < s; });
   if (it != m_windows.end() && (*it)->GetId() == id) {
     if (!duplicateOk) {
-      wpi::errs() << "GUI: ignoring duplicate window '" << id << "'\n";
+      fmt::print(stderr, "GUI: ignoring duplicate window '{}'\n", id);
       return nullptr;
     }
     return it->get();
@@ -75,11 +75,11 @@ Window* WindowManager::GetOrAddWindow(wpi::StringRef id, bool duplicateOk) {
   return m_windows.emplace(it, std::make_unique<Window>(id))->get();
 }
 
-Window* WindowManager::GetWindow(wpi::StringRef id) {
+Window* WindowManager::GetWindow(std::string_view id) {
   // binary search
   auto it = std::lower_bound(
       m_windows.begin(), m_windows.end(), id,
-      [](const auto& elem, wpi::StringRef s) { return elem->GetId() < s; });
+      [](const auto& elem, std::string_view s) { return elem->GetId() < s; });
   if (it == m_windows.end() || (*it)->GetId() != id) {
     return nullptr;
   }
diff --git a/glass/src/lib/native/cpp/hardware/AnalogInput.cpp b/glass/src/lib/native/cpp/hardware/AnalogInput.cpp
index c0f9780361..b9699a4797 100644
--- a/glass/src/lib/native/cpp/hardware/AnalogInput.cpp
+++ b/glass/src/lib/native/cpp/hardware/AnalogInput.cpp
@@ -48,7 +48,7 @@ void glass::DisplayAnalogInput(AnalogInputModel* model, int index) {
 }
 
 void glass::DisplayAnalogInputs(AnalogInputsModel* model,
-                                wpi::StringRef noneMsg) {
+                                std::string_view noneMsg) {
   ImGui::Text("(Use Ctrl+Click to edit value)");
   bool hasAny = false;
   bool first = true;
@@ -65,6 +65,6 @@ void glass::DisplayAnalogInputs(AnalogInputsModel* model,
     hasAny = true;
   });
   if (!hasAny && !noneMsg.empty()) {
-    ImGui::TextUnformatted(noneMsg.begin(), noneMsg.end());
+    ImGui::TextUnformatted(noneMsg.data(), noneMsg.data() + noneMsg.size());
   }
 }
diff --git a/glass/src/lib/native/cpp/hardware/DIO.cpp b/glass/src/lib/native/cpp/hardware/DIO.cpp
index 4d8cdf2a73..59d71f892e 100644
--- a/glass/src/lib/native/cpp/hardware/DIO.cpp
+++ b/glass/src/lib/native/cpp/hardware/DIO.cpp
@@ -104,7 +104,7 @@ void glass::DisplayDIO(DIOModel* model, int index, bool outputsEnabled) {
 }
 
 void glass::DisplayDIOs(DIOsModel* model, bool outputsEnabled,
-                        wpi::StringRef noneMsg) {
+                        std::string_view noneMsg) {
   bool hasAny = false;
 
   ImGui::PushItemWidth(ImGui::GetFontSize() * 8);
@@ -116,6 +116,6 @@ void glass::DisplayDIOs(DIOsModel* model, bool outputsEnabled,
   });
   ImGui::PopItemWidth();
   if (!hasAny && !noneMsg.empty()) {
-    ImGui::TextUnformatted(noneMsg.begin(), noneMsg.end());
+    ImGui::TextUnformatted(noneMsg.data(), noneMsg.data() + noneMsg.size());
   }
 }
diff --git a/glass/src/lib/native/cpp/hardware/Encoder.cpp b/glass/src/lib/native/cpp/hardware/Encoder.cpp
index eca2840e5d..599a5b8a50 100644
--- a/glass/src/lib/native/cpp/hardware/Encoder.cpp
+++ b/glass/src/lib/native/cpp/hardware/Encoder.cpp
@@ -4,6 +4,7 @@
 
 #include "glass/hardware/Encoder.h"
 
+#include <fmt/format.h>
 #include <imgui.h>
 
 #include "glass/Context.h"
@@ -11,8 +12,8 @@
 
 using namespace glass;
 
-void EncoderModel::SetName(const wpi::Twine& name) {
-  if (name.str().empty()) {
+void EncoderModel::SetName(std::string_view name) {
+  if (name.empty()) {
     if (auto distancePerPulse = GetDistancePerPulseData()) {
       distancePerPulse->SetName("");
     }
@@ -33,22 +34,22 @@ void EncoderModel::SetName(const wpi::Twine& name) {
     }
   } else {
     if (auto distancePerPulse = GetDistancePerPulseData()) {
-      distancePerPulse->SetName(name + " Distance/Count");
+      distancePerPulse->SetName(fmt::format("{} Distance/Count", name));
     }
     if (auto count = GetCountData()) {
-      count->SetName(name + " Count");
+      count->SetName(fmt::format("{} Count", name));
     }
     if (auto period = GetPeriodData()) {
-      period->SetName(name + " Period");
+      period->SetName(fmt::format("{} Period", name));
     }
     if (auto direction = GetDirectionData()) {
-      direction->SetName(name + " Direction");
+      direction->SetName(fmt::format("{} Direction", name));
     }
     if (auto distance = GetDistanceData()) {
-      distance->SetName(name + " Distance");
+      distance->SetName(fmt::format("{} Distance", name));
     }
     if (auto rate = GetRateData()) {
-      rate->SetName(name + " Rate");
+      rate->SetName(fmt::format("{} Rate", name));
     }
   }
 }
@@ -153,7 +154,7 @@ void glass::DisplayEncoder(EncoderModel* model) {
   ImGui::PopItemWidth();
 }
 
-void glass::DisplayEncoders(EncodersModel* model, wpi::StringRef noneMsg) {
+void glass::DisplayEncoders(EncodersModel* model, std::string_view noneMsg) {
   bool hasAny = false;
   model->ForEachEncoder([&](EncoderModel& encoder, int i) {
     hasAny = true;
@@ -162,6 +163,6 @@ void glass::DisplayEncoders(EncodersModel* model, wpi::StringRef noneMsg) {
     PopID();
   });
   if (!hasAny && !noneMsg.empty()) {
-    ImGui::TextUnformatted(noneMsg.begin(), noneMsg.end());
+    ImGui::TextUnformatted(noneMsg.data(), noneMsg.data() + noneMsg.size());
   }
 }
diff --git a/glass/src/lib/native/cpp/hardware/PCM.cpp b/glass/src/lib/native/cpp/hardware/PCM.cpp
index 400df689ba..23746be142 100644
--- a/glass/src/lib/native/cpp/hardware/PCM.cpp
+++ b/glass/src/lib/native/cpp/hardware/PCM.cpp
@@ -83,7 +83,7 @@ bool glass::DisplayPCMSolenoids(PCMModel* model, int index,
 }
 
 void glass::DisplayPCMsSolenoids(PCMsModel* model, bool outputsEnabled,
-                                 wpi::StringRef noneMsg) {
+                                 std::string_view noneMsg) {
   bool hasAny = false;
   model->ForEachPCM([&](PCMModel& pcm, int i) {
     PushID(i);
@@ -93,7 +93,7 @@ void glass::DisplayPCMsSolenoids(PCMsModel* model, bool outputsEnabled,
     PopID();
   });
   if (!hasAny && !noneMsg.empty()) {
-    ImGui::TextUnformatted(noneMsg.begin(), noneMsg.end());
+    ImGui::TextUnformatted(noneMsg.data(), noneMsg.data() + noneMsg.size());
   }
 }
 
diff --git a/glass/src/lib/native/cpp/hardware/PDP.cpp b/glass/src/lib/native/cpp/hardware/PDP.cpp
index 23871cabc2..af70116989 100644
--- a/glass/src/lib/native/cpp/hardware/PDP.cpp
+++ b/glass/src/lib/native/cpp/hardware/PDP.cpp
@@ -79,7 +79,7 @@ void glass::DisplayPDP(PDPModel* model, int index) {
   }
 }
 
-void glass::DisplayPDPs(PDPsModel* model, wpi::StringRef noneMsg) {
+void glass::DisplayPDPs(PDPsModel* model, std::string_view noneMsg) {
   bool hasAny = false;
   model->ForEachPDP([&](PDPModel& pdp, int i) {
     hasAny = true;
@@ -88,6 +88,6 @@ void glass::DisplayPDPs(PDPsModel* model, wpi::StringRef noneMsg) {
     PopID();
   });
   if (!hasAny && !noneMsg.empty()) {
-    ImGui::TextUnformatted(noneMsg.begin(), noneMsg.end());
+    ImGui::TextUnformatted(noneMsg.data(), noneMsg.data() + noneMsg.size());
   }
 }
diff --git a/glass/src/lib/native/cpp/hardware/PWM.cpp b/glass/src/lib/native/cpp/hardware/PWM.cpp
index 6fbc6243b5..3ff8e5273b 100644
--- a/glass/src/lib/native/cpp/hardware/PWM.cpp
+++ b/glass/src/lib/native/cpp/hardware/PWM.cpp
@@ -41,7 +41,7 @@ void glass::DisplayPWM(PWMModel* model, int index, bool outputsEnabled) {
 }
 
 void glass::DisplayPWMs(PWMsModel* model, bool outputsEnabled,
-                        wpi::StringRef noneMsg) {
+                        std::string_view noneMsg) {
   bool hasAny = false;
   bool first = true;
   model->ForEachPWM([&](PWMModel& pwm, int i) {
@@ -58,6 +58,6 @@ void glass::DisplayPWMs(PWMsModel* model, bool outputsEnabled,
     PopID();
   });
   if (!hasAny && !noneMsg.empty()) {
-    ImGui::TextUnformatted(noneMsg.begin(), noneMsg.end());
+    ImGui::TextUnformatted(noneMsg.data(), noneMsg.data() + noneMsg.size());
   }
 }
diff --git a/glass/src/lib/native/cpp/hardware/Relay.cpp b/glass/src/lib/native/cpp/hardware/Relay.cpp
index f0dbbf7209..59bbc51b64 100644
--- a/glass/src/lib/native/cpp/hardware/Relay.cpp
+++ b/glass/src/lib/native/cpp/hardware/Relay.cpp
@@ -60,7 +60,7 @@ void glass::DisplayRelay(RelayModel* model, int index, bool outputsEnabled) {
 }
 
 void glass::DisplayRelays(RelaysModel* model, bool outputsEnabled,
-                          wpi::StringRef noneMsg) {
+                          std::string_view noneMsg) {
   bool hasAny = false;
   bool first = true;
   model->ForEachRelay([&](RelayModel& relay, int i) {
@@ -77,6 +77,6 @@ void glass::DisplayRelays(RelaysModel* model, bool outputsEnabled,
     PopID();
   });
   if (!hasAny && !noneMsg.empty()) {
-    ImGui::TextUnformatted(noneMsg.begin(), noneMsg.end());
+    ImGui::TextUnformatted(noneMsg.data(), noneMsg.data() + noneMsg.size());
   }
 }
diff --git a/glass/src/lib/native/cpp/other/Field2D.cpp b/glass/src/lib/native/cpp/other/Field2D.cpp
index 0fda587ee7..e926019674 100644
--- a/glass/src/lib/native/cpp/other/Field2D.cpp
+++ b/glass/src/lib/native/cpp/other/Field2D.cpp
@@ -6,9 +6,12 @@
 
 #include <algorithm>
 #include <cmath>
+#include <cstdio>
 #include <memory>
+#include <string_view>
 #include <utility>
 
+#include <fmt/format.h>
 #include <frc/geometry/Pose2d.h>
 #include <frc/geometry/Rotation2d.h>
 #include <frc/geometry/Translation2d.h>
@@ -21,11 +24,11 @@
 #include <units/angle.h>
 #include <units/length.h>
 #include <wpi/SmallString.h>
+#include <wpi/StringExtras.h>
 #include <wpi/StringMap.h>
 #include <wpi/fs.h>
 #include <wpi/json.h>
 #include <wpi/raw_istream.h>
-#include <wpi/raw_ostream.h>
 #include <wpigui.h>
 
 #include "glass/Context.h"
@@ -229,7 +232,7 @@ class FieldInfo {
  private:
   void Reset();
   bool LoadImageImpl(const char* fn);
-  void LoadJson(const wpi::Twine& jsonfile);
+  void LoadJson(std::string_view jsonfile);
 
   std::unique_ptr<pfd::open_file> m_fileOpener;
 
@@ -377,7 +380,7 @@ void FieldInfo::LoadImage() {
   if (m_fileOpener && m_fileOpener->ready(0)) {
     auto result = m_fileOpener->result();
     if (!result.empty()) {
-      if (wpi::StringRef(result[0]).endswith(".json")) {
+      if (wpi::ends_with(result[0], ".json")) {
         LoadJson(result[0]);
       } else {
         LoadImageImpl(result[0].c_str());
@@ -396,11 +399,11 @@ void FieldInfo::LoadImage() {
   }
 }
 
-void FieldInfo::LoadJson(const wpi::Twine& jsonfile) {
+void FieldInfo::LoadJson(std::string_view jsonfile) {
   std::error_code ec;
   wpi::raw_fd_istream f(jsonfile, ec);
   if (ec) {
-    wpi::errs() << "GUI: could not open field JSON file\n";
+    std::fputs("GUI: could not open field JSON file\n", stderr);
     return;
   }
 
@@ -409,12 +412,12 @@ void FieldInfo::LoadJson(const wpi::Twine& jsonfile) {
   try {
     j = wpi::json::parse(f);
   } catch (const wpi::json::parse_error& e) {
-    wpi::errs() << "GUI: JSON: could not parse: " << e.what() << '\n';
+    fmt::print(stderr, "GUI: JSON: could not parse: {}\n", e.what());
   }
 
   // top level must be an object
   if (!j.is_object()) {
-    wpi::errs() << "GUI: JSON: does not contain a top object\n";
+    std::fputs("GUI: JSON: does not contain a top object\n", stderr);
     return;
   }
 
@@ -423,8 +426,7 @@ void FieldInfo::LoadJson(const wpi::Twine& jsonfile) {
   try {
     image = j.at("field-image").get<std::string>();
   } catch (const wpi::json::exception& e) {
-    wpi::errs() << "GUI: JSON: could not read field-image: " << e.what()
-                << '\n';
+    fmt::print(stderr, "GUI: JSON: could not read field-image: {}\n", e.what());
     return;
   }
 
@@ -436,8 +438,8 @@ void FieldInfo::LoadJson(const wpi::Twine& jsonfile) {
     bottom = j.at("field-corners").at("bottom-right").at(1).get<int>();
     right = j.at("field-corners").at("bottom-right").at(0).get<int>();
   } catch (const wpi::json::exception& e) {
-    wpi::errs() << "GUI: JSON: could not read field-corners: " << e.what()
-                << '\n';
+    fmt::print(stderr, "GUI: JSON: could not read field-corners: {}\n",
+               e.what());
     return;
   }
 
@@ -448,7 +450,7 @@ void FieldInfo::LoadJson(const wpi::Twine& jsonfile) {
     width = j.at("field-size").at(0).get<float>();
     height = j.at("field-size").at(1).get<float>();
   } catch (const wpi::json::exception& e) {
-    wpi::errs() << "GUI: JSON: could not read field-size: " << e.what() << '\n';
+    fmt::print(stderr, "GUI: JSON: could not read field-size: {}\n", e.what());
     return;
   }
 
@@ -457,7 +459,7 @@ void FieldInfo::LoadJson(const wpi::Twine& jsonfile) {
   try {
     unit = j.at("field-unit").get<std::string>();
   } catch (const wpi::json::exception& e) {
-    wpi::errs() << "GUI: JSON: could not read field-unit: " << e.what() << '\n';
+    fmt::print(stderr, "GUI: JSON: could not read field-unit: {}\n", e.what());
     return;
   }
 
@@ -468,7 +470,7 @@ void FieldInfo::LoadJson(const wpi::Twine& jsonfile) {
   }
 
   // the image filename is relative to the json file
-  auto pathname = fs::path{jsonfile.str()}.replace_filename(image).string();
+  auto pathname = fs::path{jsonfile}.replace_filename(image).string();
 
   // load field image
   if (!LoadImageImpl(pathname.c_str())) {
@@ -486,10 +488,10 @@ void FieldInfo::LoadJson(const wpi::Twine& jsonfile) {
 }
 
 bool FieldInfo::LoadImageImpl(const char* fn) {
-  wpi::outs() << "GUI: loading field image '" << fn << "'\n";
+  fmt::print("GUI: loading field image '{}'\n", fn);
   auto texture = gui::Texture::CreateFromFile(fn);
   if (!texture) {
-    wpi::errs() << "GUI: could not read field image\n";
+    std::puts("GUI: could not read field image");
     return false;
   }
   m_texture = std::move(texture);
@@ -679,10 +681,10 @@ void ObjectInfo::LoadImage() {
 }
 
 bool ObjectInfo::LoadImageImpl(const char* fn) {
-  wpi::outs() << "GUI: loading object image '" << fn << "'\n";
+  fmt::print("GUI: loading object image '{}'\n", fn);
   auto texture = gui::Texture::CreateFromFile(fn);
   if (!texture) {
-    wpi::errs() << "GUI: could not read object image\n";
+    std::fputs("GUI: could not read object image\n", stderr);
     return false;
   }
   m_texture = std::move(texture);
@@ -883,7 +885,7 @@ void glass::DisplayField2DSettings(Field2DModel* model) {
     }
     auto obj = objRef.get();
 
-    wpi::SmallString<64> nameBuf = name;
+    wpi::SmallString<64> nameBuf{name};
     if (ImGui::CollapsingHeader(nameBuf.c_str())) {
       obj->DisplaySettings();
     }
@@ -899,7 +901,7 @@ class FieldDisplay {
                const ImVec2& contentSize);
 
  private:
-  void DisplayObject(FieldObjectModel& model, wpi::StringRef name);
+  void DisplayObject(FieldObjectModel& model, std::string_view name);
 
   FieldInfo* m_field;
   ImVec2 m_mousePos;
@@ -1018,7 +1020,8 @@ void FieldDisplay::Display(FieldInfo* field, Field2DModel* model,
   }
 }
 
-void FieldDisplay::DisplayObject(FieldObjectModel& model, wpi::StringRef name) {
+void FieldDisplay::DisplayObject(FieldObjectModel& model,
+                                 std::string_view name) {
   PushID(name);
   auto& objRef = m_field->m_objects[name];
   if (!objRef) {
diff --git a/glass/src/lib/native/cpp/other/Log.cpp b/glass/src/lib/native/cpp/other/Log.cpp
index 8e6db5d4aa..9a1d2c5cc2 100644
--- a/glass/src/lib/native/cpp/other/Log.cpp
+++ b/glass/src/lib/native/cpp/other/Log.cpp
@@ -5,7 +5,6 @@
 #include "glass/other/Log.h"
 
 #include <imgui.h>
-#include <wpi/raw_ostream.h>
 
 using namespace glass;
 
@@ -17,14 +16,13 @@ void LogData::Clear() {
   m_lineOffsets.push_back(0);
 }
 
-void LogData::Append(const wpi::Twine& msg) {
+void LogData::Append(std::string_view msg) {
   if (m_lineOffsets.size() >= m_maxLines) {
     Clear();
   }
 
   size_t oldSize = m_buf.size();
-  wpi::raw_string_ostream os{m_buf};
-  msg.print(os);
+  m_buf.append(msg);
   for (size_t newSize = m_buf.size(); oldSize < newSize; ++oldSize) {
     if (m_buf[oldSize] == '\n') {
       m_lineOffsets.push_back(oldSize + 1);
diff --git a/glass/src/lib/native/cpp/other/Mechanism2D.cpp b/glass/src/lib/native/cpp/other/Mechanism2D.cpp
index 86e7d898a8..07e83e2f86 100644
--- a/glass/src/lib/native/cpp/other/Mechanism2D.cpp
+++ b/glass/src/lib/native/cpp/other/Mechanism2D.cpp
@@ -6,9 +6,12 @@
 
 #include <algorithm>
 #include <cmath>
+#include <cstdio>
 #include <memory>
+#include <string_view>
 #include <utility>
 
+#include <fmt/format.h>
 #include <frc/geometry/Pose2d.h>
 #include <frc/geometry/Rotation2d.h>
 #include <frc/geometry/Transform2d.h>
@@ -21,7 +24,6 @@
 #include <portable-file-dialogs.h>
 #include <units/angle.h>
 #include <units/length.h>
-#include <wpi/raw_ostream.h>
 #include <wpigui.h>
 
 #include "glass/Context.h"
@@ -125,10 +127,10 @@ void BackgroundInfo::LoadImage() {
 }
 
 bool BackgroundInfo::LoadImageImpl(const char* fn) {
-  wpi::outs() << "GUI: loading background image '" << fn << "'\n";
+  fmt::print("GUI: loading background image '{}'\n", fn);
   auto texture = gui::Texture::CreateFromFile(fn);
   if (!texture) {
-    wpi::errs() << "GUI: could not read background image\n";
+    std::puts("GUI: could not read background image");
     return false;
   }
   m_texture = std::move(texture);
@@ -182,7 +184,7 @@ void glass::DisplayMechanism2DSettings(Mechanism2DModel* model) {
 void FrameData::DrawObject(ImDrawList* drawList, MechanismObjectModel& objModel,
                            const frc::Pose2d& pose) const {
   const char* type = objModel.GetType();
-  if (wpi::StringRef{type} == "line") {
+  if (std::string_view{type} == "line") {
     auto startPose =
         pose + frc::Transform2d{frc::Translation2d{}, objModel.GetAngle()};
     auto endPose =
diff --git a/glass/src/lib/native/cpp/other/Plot.cpp b/glass/src/lib/native/cpp/other/Plot.cpp
index 7faa54ad11..372f8c959b 100644
--- a/glass/src/lib/native/cpp/other/Plot.cpp
+++ b/glass/src/lib/native/cpp/other/Plot.cpp
@@ -12,8 +12,11 @@
 #include <cstring>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <vector>
 
+#include <fmt/format.h>
+
 #define IMGUI_DEFINE_MATH_OPERATORS
 #include <imgui.h>
 #include <imgui_internal.h>
@@ -23,6 +26,7 @@
 #include <wpi/Signal.h>
 #include <wpi/SmallString.h>
 #include <wpi/SmallVector.h>
+#include <wpi/StringExtras.h>
 #include <wpi/timestamp.h>
 
 #include "glass/Context.h"
@@ -42,7 +46,7 @@ struct PlotSeriesRef {
 
 class PlotSeries {
  public:
-  explicit PlotSeries(wpi::StringRef id);
+  explicit PlotSeries(std::string_view id);
   explicit PlotSeries(DataSource* source, int yAxis = 0);
 
   const std::string& GetId() const { return m_id; }
@@ -52,7 +56,7 @@ class PlotSeries {
   void SetSource(DataSource* source);
   DataSource* GetSource() const { return m_source; }
 
-  bool ReadIni(wpi::StringRef name, wpi::StringRef value);
+  bool ReadIni(std::string_view name, std::string_view value);
   void WriteIni(ImGuiTextBuffer* out);
 
   enum Action { kNone, kMoveUp, kMoveDown, kDelete };
@@ -102,7 +106,7 @@ class Plot {
  public:
   Plot();
 
-  bool ReadIni(wpi::StringRef name, wpi::StringRef value);
+  bool ReadIni(std::string_view name, std::string_view value);
   void WriteIni(ImGuiTextBuffer* out);
 
   void DragDropTarget(PlotView& view, size_t i, bool inPlot);
@@ -164,7 +168,7 @@ class PlotView : public View {
 
 }  // namespace
 
-PlotSeries::PlotSeries(wpi::StringRef id) : m_id(id) {
+PlotSeries::PlotSeries(std::string_view id) : m_id(id) {
   if (DataSource* source = DataSource::Find(id)) {
     SetSource(source);
     return;
@@ -241,55 +245,45 @@ void PlotSeries::AppendValue(double value, uint64_t timeUs) {
   }
 }
 
-bool PlotSeries::ReadIni(wpi::StringRef name, wpi::StringRef value) {
+bool PlotSeries::ReadIni(std::string_view name, std::string_view value) {
   if (name == "name") {
     m_name = value;
     return true;
   }
   if (name == "yAxis") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return true;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      m_yAxis = num.value();
     }
-    m_yAxis = num;
     return true;
   } else if (name == "color") {
-    unsigned int num;
-    if (value.getAsInteger(10, num)) {
-      return true;
+    if (auto num = wpi::parse_integer<unsigned int>(value, 10)) {
+      m_color = ImColor(num.value());
     }
-    m_color = ImColor(num);
     return true;
   } else if (name == "marker") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return true;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      m_marker = num.value();
     }
-    m_marker = num;
     return true;
   } else if (name == "weight") {
-    std::sscanf(value.data(), "%f", &m_weight);
+    if (auto num = wpi::parse_float<float>(value)) {
+      m_weight = num.value();
+    }
     return true;
   } else if (name == "digital") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return true;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      m_digital = num.value();
     }
-    m_digital = num;
     return true;
   } else if (name == "digitalBitHeight") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return true;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      m_digitalBitHeight = num.value();
     }
-    m_digitalBitHeight = num;
     return true;
   } else if (name == "digitalBitGap") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return true;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      m_digitalBitGap = num.value();
     }
-    m_digitalBitGap = num;
     return true;
   }
   return false;
@@ -478,121 +472,93 @@ Plot::Plot() {
   }
 }
 
-bool Plot::ReadIni(wpi::StringRef name, wpi::StringRef value) {
+bool Plot::ReadIni(std::string_view name, std::string_view value) {
   if (name == "name") {
     m_name = value;
     return true;
   } else if (name == "visible") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return true;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      m_visible = num.value() != 0;
     }
-    m_visible = num != 0;
     return true;
   } else if (name == "showPause") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return true;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      m_showPause = num.value() != 0;
     }
-    m_showPause = num != 0;
     return true;
   } else if (name == "lockPrevX") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return true;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      m_lockPrevX = num.value() != 0;
     }
-    m_lockPrevX = num != 0;
     return true;
   } else if (name == "legend") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return true;
-    }
-    if (num == 0) {
-      m_plotFlags |= ImPlotFlags_NoLegend;
-    } else {
-      m_plotFlags &= ~ImPlotFlags_NoLegend;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      if (num.value() == 0) {
+        m_plotFlags |= ImPlotFlags_NoLegend;
+      } else {
+        m_plotFlags &= ~ImPlotFlags_NoLegend;
+      }
     }
     return true;
   } else if (name == "yaxis2") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return true;
-    }
-    if (num == 0) {
-      m_plotFlags &= ~ImPlotFlags_YAxis2;
-    } else {
-      m_plotFlags |= ImPlotFlags_YAxis2;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      if (num.value() == 0) {
+        m_plotFlags &= ~ImPlotFlags_YAxis2;
+      } else {
+        m_plotFlags |= ImPlotFlags_YAxis2;
+      }
     }
     return true;
   } else if (name == "yaxis3") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return true;
-    }
-    if (num == 0) {
-      m_plotFlags &= ~ImPlotFlags_YAxis3;
-    } else {
-      m_plotFlags |= ImPlotFlags_YAxis3;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      if (num.value() == 0) {
+        m_plotFlags &= ~ImPlotFlags_YAxis3;
+      } else {
+        m_plotFlags |= ImPlotFlags_YAxis3;
+      }
     }
     return true;
   } else if (name == "viewTime") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return true;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      m_viewTime = num.value() / 1000.0;
     }
-    m_viewTime = num / 1000.0;
     return true;
   } else if (name == "autoHeight") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return true;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      m_autoHeight = num.value() != 0;
     }
-    m_autoHeight = num != 0;
     return true;
   } else if (name == "height") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return true;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      m_height = num.value();
     }
-    m_height = num;
     return true;
-  } else if (name.startswith("y")) {
-    auto [yAxisStr, yName] = name.split('_');
-    int yAxis;
-    if (yAxisStr.substr(1).getAsInteger(10, yAxis)) {
-      return false;
-    }
+  } else if (wpi::starts_with(name, 'y')) {
+    auto [yAxisStr, yName] = wpi::split(name, '_');
+    int yAxis =
+        wpi::parse_integer<int>(wpi::drop_front(yAxisStr), 10).value_or(-1);
     if (yAxis < 0 || yAxis > 3) {
       return false;
     }
     if (yName == "min") {
-      int num;
-      if (value.getAsInteger(10, num)) {
-        return true;
+      if (auto num = wpi::parse_integer<int>(value, 10)) {
+        m_axisRange[yAxis].min = num.value() / 1000.0;
       }
-      m_axisRange[yAxis].min = num / 1000.0;
       return true;
     } else if (yName == "max") {
-      int num;
-      if (value.getAsInteger(10, num)) {
-        return true;
+      if (auto num = wpi::parse_integer<int>(value, 10)) {
+        m_axisRange[yAxis].max = num.value() / 1000.0;
       }
-      m_axisRange[yAxis].max = num / 1000.0;
       return true;
     } else if (yName == "lockMin") {
-      int num;
-      if (value.getAsInteger(10, num)) {
-        return true;
+      if (auto num = wpi::parse_integer<int>(value, 10)) {
+        m_axisRange[yAxis].lockMin = num.value() != 0;
       }
-      m_axisRange[yAxis].lockMin = num != 0;
       return true;
     } else if (yName == "lockMax") {
-      int num;
-      if (value.getAsInteger(10, num)) {
-        return true;
+      if (auto num = wpi::parse_integer<int>(value, 10)) {
+        m_axisRange[yAxis].lockMax = num.value() != 0;
       }
-      m_axisRange[yAxis].lockMax = num != 0;
       return true;
     } else if (yName == "label") {
       m_axisLabel[yAxis] = value;
@@ -960,10 +926,10 @@ void PlotView::MovePlotSeries(PlotView* fromView, size_t fromPlotIndex,
   }
 }
 
-PlotProvider::PlotProvider(const wpi::Twine& iniName)
-    : WindowManager{iniName + "Window"},
+PlotProvider::PlotProvider(std::string_view iniName)
+    : WindowManager{fmt::format("{}Window", iniName)},
       m_plotSaver{iniName, this, false},
-      m_seriesSaver{iniName + "Series", this, true} {}
+      m_seriesSaver{fmt::format("{}Series", iniName), this, true} {}
 
 PlotProvider::~PlotProvider() = default;
 
@@ -1021,21 +987,23 @@ void PlotProvider::DisplayWindows() {
   WindowManager::DisplayWindows();
 }
 
-PlotProvider::IniSaver::IniSaver(const wpi::Twine& typeName,
+PlotProvider::IniSaver::IniSaver(std::string_view typeName,
                                  PlotProvider* provider, bool forSeries)
     : IniSaverBase{typeName}, m_provider{provider}, m_forSeries{forSeries} {}
 
 void* PlotProvider::IniSaver::IniReadOpen(const char* name) {
-  auto [viewId, plotNumStr] = wpi::StringRef{name}.split('#');
-  wpi::StringRef seriesId;
+  auto [viewId, plotNumStr] = wpi::split(name, '#');
+  std::string_view seriesId;
   if (m_forSeries) {
-    std::tie(plotNumStr, seriesId) = plotNumStr.split('#');
+    std::tie(plotNumStr, seriesId) = wpi::split(plotNumStr, '#');
     if (seriesId.empty()) {
       return nullptr;
     }
   }
   unsigned int plotNum;
-  if (plotNumStr.getAsInteger(10, plotNum)) {
+  if (auto plotNumOpt = wpi::parse_integer<unsigned int>(plotNumStr, 10)) {
+    plotNum = plotNumOpt.value();
+  } else {
     return nullptr;
   }
 
@@ -1071,10 +1039,10 @@ void* PlotProvider::IniSaver::IniReadOpen(const char* name) {
       .get();
 }
 
-void PlotProvider::IniSaver::IniReadLine(void* entry, const char* lineStr) {
-  auto [name, value] = wpi::StringRef{lineStr}.split('=');
-  name = name.trim();
-  value = value.trim();
+void PlotProvider::IniSaver::IniReadLine(void* entry, const char* line) {
+  auto [name, value] = wpi::split(line, '=');
+  name = wpi::trim(name);
+  value = wpi::trim(value);
   if (m_forSeries) {
     static_cast<PlotSeries*>(entry)->ReadIni(name, value);
   } else {
diff --git a/glass/src/lib/native/cpp/support/IniSaverBase.cpp b/glass/src/lib/native/cpp/support/IniSaverBase.cpp
index e222818d03..ae8d811d41 100644
--- a/glass/src/lib/native/cpp/support/IniSaverBase.cpp
+++ b/glass/src/lib/native/cpp/support/IniSaverBase.cpp
@@ -54,9 +54,8 @@ static ImGuiSaver* GetSaverInstance() {
   return inst;
 }
 
-IniSaverBase::IniSaverBase(const wpi::Twine& typeName, IniSaverBackend* backend)
-    : m_typeName(typeName.str()),
-      m_backend{backend ? backend : GetSaverInstance()} {}
+IniSaverBase::IniSaverBase(std::string_view typeName, IniSaverBackend* backend)
+    : m_typeName(typeName), m_backend{backend ? backend : GetSaverInstance()} {}
 
 IniSaverBase::~IniSaverBase() {
   m_backend->Unregister(this);
diff --git a/glass/src/lib/native/cpp/support/IniSaverInfo.cpp b/glass/src/lib/native/cpp/support/IniSaverInfo.cpp
index 32911da255..6525e8e69d 100644
--- a/glass/src/lib/native/cpp/support/IniSaverInfo.cpp
+++ b/glass/src/lib/native/cpp/support/IniSaverInfo.cpp
@@ -8,15 +8,13 @@
 #include <cstring>
 
 #include <imgui_internal.h>
-#include <wpi/SmallString.h>
+#include <wpi/StringExtras.h>
 
 using namespace glass;
 
-void NameInfo::SetName(const wpi::Twine& name) {
-  wpi::SmallString<64> nameBuf;
-  auto nameStr = name.toStringRef(nameBuf);
-  size_t len = (std::min)(nameStr.size(), sizeof(m_name) - 1);
-  std::memcpy(m_name, nameStr.data(), len);
+void NameInfo::SetName(std::string_view name) {
+  size_t len = (std::min)(name.size(), sizeof(m_name) - 1);
+  std::memcpy(m_name, name.data(), len);
   m_name[len] = '\0';
 }
 
@@ -74,7 +72,7 @@ void NameInfo::GetLabel(char* buf, size_t size, const char* defaultName,
   }
 }
 
-bool NameInfo::ReadIni(wpi::StringRef name, wpi::StringRef value) {
+bool NameInfo::ReadIni(std::string_view name, std::string_view value) {
   if (name != "name") {
     return false;
   }
@@ -140,15 +138,13 @@ bool NameInfo::InputTextName(const char* label_id, ImGuiInputTextFlags flags) {
   return ImGui::InputText(label_id, m_name, sizeof(m_name), flags);
 }
 
-bool OpenInfo::ReadIni(wpi::StringRef name, wpi::StringRef value) {
+bool OpenInfo::ReadIni(std::string_view name, std::string_view value) {
   if (name != "open") {
     return false;
   }
-  int num;
-  if (value.getAsInteger(10, num)) {
-    return true;
+  if (auto num = wpi::parse_integer<int>(value, 10)) {
+    m_open = num.value();
   }
-  m_open = num;
   return true;
 }
 
@@ -156,7 +152,7 @@ void OpenInfo::WriteIni(ImGuiTextBuffer* out) {
   out->appendf("open=%d\n", m_open ? 1 : 0);
 }
 
-bool NameOpenInfo::ReadIni(wpi::StringRef name, wpi::StringRef value) {
+bool NameOpenInfo::ReadIni(std::string_view name, std::string_view value) {
   if (NameInfo::ReadIni(name, value)) {
     return true;
   }
diff --git a/glass/src/lib/native/include/glass/Context.h b/glass/src/lib/native/include/glass/Context.h
index bb3c0209e2..62b0a33470 100644
--- a/glass/src/lib/native/include/glass/Context.h
+++ b/glass/src/lib/native/include/glass/Context.h
@@ -6,12 +6,11 @@
 
 #include <memory>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
 #include <imgui.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 
 namespace glass {
 
@@ -48,7 +47,7 @@ class Storage {
  public:
   struct Value {
     Value() = default;
-    explicit Value(const wpi::Twine& str) : stringVal{str.str()} {}
+    explicit Value(std::string_view str) : stringVal{str} {}
 
     enum Type { kNone, kInt, kInt64, kBool, kFloat, kDouble, kString };
     Type type = kNone;
@@ -62,29 +61,30 @@ class Storage {
     std::string stringVal;
   };
 
-  int GetInt(wpi::StringRef key, int defaultVal = 0) const;
-  int64_t GetInt64(wpi::StringRef key, int64_t defaultVal = 0) const;
-  bool GetBool(wpi::StringRef key, bool defaultVal = false) const;
-  float GetFloat(wpi::StringRef key, float defaultVal = 0.0f) const;
-  double GetDouble(wpi::StringRef key, double defaultVal = 0.0) const;
-  std::string GetString(wpi::StringRef key,
-                        const std::string& defaultVal = {}) const;
+  int GetInt(std::string_view key, int defaultVal = 0) const;
+  int64_t GetInt64(std::string_view key, int64_t defaultVal = 0) const;
+  bool GetBool(std::string_view key, bool defaultVal = false) const;
+  float GetFloat(std::string_view key, float defaultVal = 0.0f) const;
+  double GetDouble(std::string_view key, double defaultVal = 0.0) const;
+  std::string GetString(std::string_view key,
+                        std::string_view defaultVal = {}) const;
 
-  void SetInt(wpi::StringRef key, int val);
-  void SetInt64(wpi::StringRef key, int64_t val);
-  void SetBool(wpi::StringRef key, bool val);
-  void SetFloat(wpi::StringRef key, float val);
-  void SetDouble(wpi::StringRef key, double val);
-  void SetString(wpi::StringRef key, const wpi::Twine& val);
+  void SetInt(std::string_view key, int val);
+  void SetInt64(std::string_view key, int64_t val);
+  void SetBool(std::string_view key, bool val);
+  void SetFloat(std::string_view key, float val);
+  void SetDouble(std::string_view key, double val);
+  void SetString(std::string_view key, std::string_view val);
 
-  int* GetIntRef(wpi::StringRef key, int defaultVal = 0);
-  int64_t* GetInt64Ref(wpi::StringRef key, int64_t defaultVal = 0);
-  bool* GetBoolRef(wpi::StringRef key, bool defaultVal = false);
-  float* GetFloatRef(wpi::StringRef key, float defaultVal = 0.0f);
-  double* GetDoubleRef(wpi::StringRef key, double defaultVal = 0.0);
-  std::string* GetStringRef(wpi::StringRef key, wpi::StringRef defaultVal = {});
+  int* GetIntRef(std::string_view key, int defaultVal = 0);
+  int64_t* GetInt64Ref(std::string_view key, int64_t defaultVal = 0);
+  bool* GetBoolRef(std::string_view key, bool defaultVal = false);
+  float* GetFloatRef(std::string_view key, float defaultVal = 0.0f);
+  double* GetDoubleRef(std::string_view key, double defaultVal = 0.0);
+  std::string* GetStringRef(std::string_view key,
+                            std::string_view defaultVal = {});
 
-  Value& GetValue(wpi::StringRef key);
+  Value& GetValue(std::string_view key);
 
   void SetData(std::shared_ptr<void>&& data) { m_data = std::move(data); }
 
@@ -111,7 +111,7 @@ class Storage {
 };
 
 Storage& GetStorage();
-Storage& GetStorage(wpi::StringRef id);
+Storage& GetStorage(std::string_view id);
 
 bool Begin(const char* name, bool* p_open = nullptr,
            ImGuiWindowFlags flags = 0);
@@ -141,8 +141,8 @@ void PushID(const char* str_id);
 void PushID(const char* str_id_begin, const char* str_id_end);
 
 // push string into the ID stack (will hash string).
-inline void PushID(wpi::StringRef str) {
-  PushID(str.begin(), str.end());
+inline void PushID(std::string_view str) {
+  PushID(str.data(), str.data() + str.size());
 }
 
 // push integer into the ID stack (will hash integer).
diff --git a/glass/src/lib/native/include/glass/ContextInternal.h b/glass/src/lib/native/include/glass/ContextInternal.h
index 58f1e21776..39e54f3925 100644
--- a/glass/src/lib/native/include/glass/ContextInternal.h
+++ b/glass/src/lib/native/include/glass/ContextInternal.h
@@ -26,7 +26,7 @@ class DataSourceName {
   DataSourceName() = default;
   explicit DataSourceName(DataSource* source) : source{source} {}
 
-  bool ReadIni(wpi::StringRef name_, wpi::StringRef value) {
+  bool ReadIni(std::string_view name_, std::string_view value) {
     return name->ReadIni(name_, value);
   }
   void WriteIni(ImGuiTextBuffer* out) { name->WriteIni(out); }
diff --git a/glass/src/lib/native/include/glass/DataSource.h b/glass/src/lib/native/include/glass/DataSource.h
index 657dbf7870..1d5c37b0d8 100644
--- a/glass/src/lib/native/include/glass/DataSource.h
+++ b/glass/src/lib/native/include/glass/DataSource.h
@@ -8,11 +8,10 @@
 
 #include <atomic>
 #include <string>
+#include <string_view>
 
 #include <imgui.h>
 #include <wpi/Signal.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 #include <wpi/spinlock.h>
 
 namespace glass {
@@ -24,9 +23,9 @@ class NameInfo;
  */
 class DataSource {
  public:
-  explicit DataSource(const wpi::Twine& id);
-  DataSource(const wpi::Twine& id, int index);
-  DataSource(const wpi::Twine& id, int index, int index2);
+  explicit DataSource(std::string_view id);
+  DataSource(std::string_view id, int index);
+  DataSource(std::string_view id, int index, int index2);
   virtual ~DataSource();
 
   DataSource(const DataSource&) = delete;
@@ -34,7 +33,7 @@ class DataSource {
 
   const char* GetId() const { return m_id.c_str(); }
 
-  void SetName(const wpi::Twine& name);
+  void SetName(std::string_view name);
   const char* GetName() const;
   NameInfo& GetNameInfo() { return *m_name; }
 
@@ -69,7 +68,7 @@ class DataSource {
 
   wpi::sig::SignalBase<wpi::spinlock, double, uint64_t> valueChanged;
 
-  static DataSource* Find(wpi::StringRef id);
+  static DataSource* Find(std::string_view id);
 
   static wpi::sig::Signal<const char*, DataSource*> sourceCreated;
 
diff --git a/glass/src/lib/native/include/glass/Provider.h b/glass/src/lib/native/include/glass/Provider.h
index 9eafbeefea..53b1e75f2d 100644
--- a/glass/src/lib/native/include/glass/Provider.h
+++ b/glass/src/lib/native/include/glass/Provider.h
@@ -8,11 +8,10 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 #include <wpigui.h>
 
 #include "glass/Model.h"
@@ -52,7 +51,7 @@ class Provider : public WindowManager {
    *
    * @param iniName Group name to use in ini file
    */
-  explicit Provider(const wpi::Twine& iniName) : WindowManager{iniName} {}
+  explicit Provider(std::string_view iniName) : WindowManager{iniName} {}
 
   Provider(const Provider&) = delete;
   Provider& operator=(const Provider&) = delete;
@@ -69,7 +68,7 @@ class Provider : public WindowManager {
    *
    * @param name View name
    */
-  void ShowDefault(wpi::StringRef name);
+  void ShowDefault(std::string_view name);
 
   /**
    * Register a model and view combination.  Equivalent to calling both
@@ -80,7 +79,7 @@ class Provider : public WindowManager {
    * @param createModel Functor for creating model
    * @param createView Functor for creating view
    */
-  void Register(wpi::StringRef name, ExistsFunc exists,
+  void Register(std::string_view name, ExistsFunc exists,
                 CreateModelFunc createModel, CreateViewFunc createView);
 
   /**
@@ -90,7 +89,7 @@ class Provider : public WindowManager {
    * @param exists Functor, returns true if model can be created
    * @param createModel Functor for creating model
    */
-  void RegisterModel(wpi::StringRef name, ExistsFunc exists,
+  void RegisterModel(std::string_view name, ExistsFunc exists,
                      CreateModelFunc createModel);
 
   /**
@@ -101,14 +100,14 @@ class Provider : public WindowManager {
    * @param exists Functor, returns true if view can be created
    * @param createView Functor for creating view
    */
-  void RegisterView(wpi::StringRef name, wpi::StringRef modelName,
+  void RegisterView(std::string_view name, std::string_view modelName,
                     ViewExistsFunc exists, CreateViewFunc createView);
 
  protected:
   virtual void Update();
 
   struct ModelEntry {
-    ModelEntry(wpi::StringRef name, ExistsFunc exists,
+    ModelEntry(std::string_view name, ExistsFunc exists,
                CreateModelFunc createModel)
         : name{name},
           exists{std::move(exists)},
@@ -122,7 +121,7 @@ class Provider : public WindowManager {
   };
 
   struct ViewEntry {
-    ViewEntry(wpi::StringRef name, ModelEntry* modelEntry,
+    ViewEntry(std::string_view name, ModelEntry* modelEntry,
               ViewExistsFunc exists, CreateViewFunc createView)
         : name{name},
           modelEntry{modelEntry},
@@ -143,16 +142,16 @@ class Provider : public WindowManager {
   using ViewEntries = std::vector<std::unique_ptr<ViewEntry>>;
   ViewEntries m_viewEntries;
 
-  typename ModelEntries::iterator FindModelEntry(wpi::StringRef name);
-  typename ViewEntries::iterator FindViewEntry(wpi::StringRef name);
+  typename ModelEntries::iterator FindModelEntry(std::string_view name);
+  typename ViewEntries::iterator FindViewEntry(std::string_view name);
 
   virtual std::unique_ptr<ModelEntry> MakeModelEntry(
-      wpi::StringRef name, ExistsFunc exists, CreateModelFunc createModel) {
+      std::string_view name, ExistsFunc exists, CreateModelFunc createModel) {
     return std::make_unique<ModelEntry>(name, std::move(exists),
                                         std::move(createModel));
   }
 
-  virtual std::unique_ptr<ViewEntry> MakeViewEntry(wpi::StringRef name,
+  virtual std::unique_ptr<ViewEntry> MakeViewEntry(std::string_view name,
                                                    ModelEntry* modelEntry,
                                                    ViewExistsFunc exists,
                                                    CreateViewFunc createView) {
diff --git a/glass/src/lib/native/include/glass/Provider.inc b/glass/src/lib/native/include/glass/Provider.inc
index 357812c659..33bb6e031d 100644
--- a/glass/src/lib/native/include/glass/Provider.inc
+++ b/glass/src/lib/native/include/glass/Provider.inc
@@ -17,7 +17,7 @@ void Provider<Functions>::GlobalInit() {
 }
 
 template <typename Functions>
-void Provider<Functions>::ShowDefault(wpi::StringRef name) {
+void Provider<Functions>::ShowDefault(std::string_view name) {
   auto win = GetWindow(name);
   if (win) {
     return;
@@ -30,7 +30,7 @@ void Provider<Functions>::ShowDefault(wpi::StringRef name) {
 }
 
 template <typename Functions>
-void Provider<Functions>::Register(wpi::StringRef name, ExistsFunc exists,
+void Provider<Functions>::Register(std::string_view name, ExistsFunc exists,
                                    CreateModelFunc createModel,
                                    CreateViewFunc createView) {
   RegisterModel(name, std::move(exists), std::move(createModel));
@@ -38,7 +38,8 @@ void Provider<Functions>::Register(wpi::StringRef name, ExistsFunc exists,
 }
 
 template <typename Functions>
-void Provider<Functions>::RegisterModel(wpi::StringRef name, ExistsFunc exists,
+void Provider<Functions>::RegisterModel(std::string_view name,
+                                        ExistsFunc exists,
                                         CreateModelFunc createModel) {
   auto it = FindModelEntry(name);
   // ignore if exists
@@ -51,8 +52,8 @@ void Provider<Functions>::RegisterModel(wpi::StringRef name, ExistsFunc exists,
 }
 
 template <typename Functions>
-void Provider<Functions>::RegisterView(wpi::StringRef name,
-                                       wpi::StringRef modelName,
+void Provider<Functions>::RegisterView(std::string_view name,
+                                       std::string_view modelName,
                                        ViewExistsFunc exists,
                                        CreateViewFunc createView) {
   // find model; if model doesn't exist, ignore
@@ -84,18 +85,18 @@ void Provider<Functions>::Update() {
 
 template <typename Functions>
 typename Provider<Functions>::ModelEntries::iterator
-Provider<Functions>::FindModelEntry(wpi::StringRef name) {
+Provider<Functions>::FindModelEntry(std::string_view name) {
   return std::lower_bound(
       m_modelEntries.begin(), m_modelEntries.end(), name,
-      [](const auto& elem, wpi::StringRef s) { return elem->name < s; });
+      [](const auto& elem, std::string_view s) { return elem->name < s; });
 }
 
 template <typename Functions>
 typename Provider<Functions>::ViewEntries::iterator
-Provider<Functions>::FindViewEntry(wpi::StringRef name) {
+Provider<Functions>::FindViewEntry(std::string_view name) {
   return std::lower_bound(
       m_viewEntries.begin(), m_viewEntries.end(), name,
-      [](const auto& elem, wpi::StringRef s) { return elem->name < s; });
+      [](const auto& elem, std::string_view s) { return elem->name < s; });
 }
 
 }  // namespace glass
diff --git a/glass/src/lib/native/include/glass/Window.h b/glass/src/lib/native/include/glass/Window.h
index 504b53e11a..780479a105 100644
--- a/glass/src/lib/native/include/glass/Window.h
+++ b/glass/src/lib/native/include/glass/Window.h
@@ -6,11 +6,10 @@
 
 #include <memory>
 #include <string>
+#include <string_view>
 #include <utility>
 
 #include <imgui.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 
 #include "glass/View.h"
 
@@ -23,9 +22,9 @@ namespace glass {
 class Window {
  public:
   Window() = default;
-  explicit Window(wpi::StringRef id) : m_id{id}, m_defaultName{id} {}
+  explicit Window(std::string_view id) : m_id{id}, m_defaultName{id} {}
 
-  wpi::StringRef GetId() const { return m_id; }
+  std::string_view GetId() const { return m_id; }
 
   enum Visibility { kHide = 0, kShow, kDisabled };
 
@@ -43,8 +42,8 @@ class Window {
 
   void SetFlags(ImGuiWindowFlags flags) { m_flags = flags; }
 
-  void SetName(const wpi::Twine& name) { m_name = name.str(); }
-  void SetDefaultName(const wpi::Twine& name) { m_defaultName = name.str(); }
+  void SetName(std::string_view name) { m_name = name; }
+  void SetDefaultName(std::string_view name) { m_defaultName = name; }
 
   /**
    * Normally windows provide a right-click popup menu on the title bar to
diff --git a/glass/src/lib/native/include/glass/WindowManager.h b/glass/src/lib/native/include/glass/WindowManager.h
index 384dd918bc..4024e1561f 100644
--- a/glass/src/lib/native/include/glass/WindowManager.h
+++ b/glass/src/lib/native/include/glass/WindowManager.h
@@ -6,13 +6,12 @@
 
 #include <functional>
 #include <memory>
+#include <string_view>
 #include <type_traits>
 #include <vector>
 
 #include <imgui.h>
 #include <wpi/FunctionExtras.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 
 #include "glass/Window.h"
 #include "glass/support/IniSaverBase.h"
@@ -34,7 +33,7 @@ class WindowManager {
    *
    * @param iniName Group name to use in ini file
    */
-  explicit WindowManager(const wpi::Twine& iniName);
+  explicit WindowManager(std::string_view iniName);
   virtual ~WindowManager() = default;
 
   WindowManager(const WindowManager&) = delete;
@@ -67,7 +66,7 @@ class WindowManager {
    * @param id unique identifier of the window (title bar)
    * @param display window contents display function
    */
-  Window* AddWindow(wpi::StringRef id, wpi::unique_function<void()> display);
+  Window* AddWindow(std::string_view id, wpi::unique_function<void()> display);
 
   /**
    * Adds window to GUI.  The view's display function is called from within a
@@ -85,7 +84,7 @@ class WindowManager {
    * @param view view object
    * @return Window, or nullptr on duplicate window
    */
-  Window* AddWindow(wpi::StringRef id, std::unique_ptr<View> view);
+  Window* AddWindow(std::string_view id, std::unique_ptr<View> view);
 
   /**
    * Adds window to GUI.  A View must be assigned to the returned Window
@@ -102,7 +101,7 @@ class WindowManager {
    * @param id unique identifier of the window (default title bar)
    * @return Window, or nullptr on duplicate window
    */
-  Window* GetOrAddWindow(wpi::StringRef id, bool duplicateOk = false);
+  Window* GetOrAddWindow(std::string_view id, bool duplicateOk = false);
 
   /**
    * Gets existing window.  If none exists, returns nullptr.
@@ -110,7 +109,7 @@ class WindowManager {
    * @param id unique identifier of the window (default title bar)
    * @return Window, or nullptr if window does not exist
    */
-  Window* GetWindow(wpi::StringRef id);
+  Window* GetWindow(std::string_view id);
 
  protected:
   virtual void DisplayWindows();
@@ -121,7 +120,7 @@ class WindowManager {
  private:
   class IniSaver : public IniSaverBase {
    public:
-    explicit IniSaver(const wpi::Twine& typeName, WindowManager* manager)
+    explicit IniSaver(std::string_view typeName, WindowManager* manager)
         : IniSaverBase{typeName}, m_manager{manager} {}
 
     void* IniReadOpen(const char* name) override;
diff --git a/glass/src/lib/native/include/glass/hardware/AnalogInput.h b/glass/src/lib/native/include/glass/hardware/AnalogInput.h
index 3ddbd9c3fa..10f4b40b79 100644
--- a/glass/src/lib/native/include/glass/hardware/AnalogInput.h
+++ b/glass/src/lib/native/include/glass/hardware/AnalogInput.h
@@ -4,8 +4,9 @@
 
 #pragma once
 
+#include <string_view>
+
 #include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
 
 #include "glass/Model.h"
 
@@ -31,6 +32,6 @@ class AnalogInputsModel : public Model {
 
 void DisplayAnalogInput(AnalogInputModel* model, int index);
 void DisplayAnalogInputs(AnalogInputsModel* model,
-                         wpi::StringRef noneMsg = "No analog inputs");
+                         std::string_view noneMsg = "No analog inputs");
 
 }  // namespace glass
diff --git a/glass/src/lib/native/include/glass/hardware/DIO.h b/glass/src/lib/native/include/glass/hardware/DIO.h
index 830edb10f5..a8236f3487 100644
--- a/glass/src/lib/native/include/glass/hardware/DIO.h
+++ b/glass/src/lib/native/include/glass/hardware/DIO.h
@@ -4,8 +4,9 @@
 
 #pragma once
 
+#include <string_view>
+
 #include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
 
 #include "glass/Model.h"
 
@@ -57,6 +58,6 @@ class DIOsModel : public Model {
 
 void DisplayDIO(DIOModel* model, int index, bool outputsEnabled);
 void DisplayDIOs(DIOsModel* model, bool outputsEnabled,
-                 wpi::StringRef noneMsg = "No Digital I/O");
+                 std::string_view noneMsg = "No Digital I/O");
 
 }  // namespace glass
diff --git a/glass/src/lib/native/include/glass/hardware/Encoder.h b/glass/src/lib/native/include/glass/hardware/Encoder.h
index 31ac8bfcf6..d553ef10fa 100644
--- a/glass/src/lib/native/include/glass/hardware/Encoder.h
+++ b/glass/src/lib/native/include/glass/hardware/Encoder.h
@@ -4,8 +4,9 @@
 
 #pragma once
 
+#include <string_view>
+
 #include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
 
 #include "glass/Model.h"
 
@@ -15,7 +16,7 @@ class DataSource;
 
 class EncoderModel : public Model {
  public:
-  virtual void SetName(const wpi::Twine& name);
+  virtual void SetName(std::string_view name);
 
   virtual const char* GetSimDevice() const = 0;
 
@@ -51,6 +52,6 @@ class EncodersModel : public Model {
 
 void DisplayEncoder(EncoderModel* model);
 void DisplayEncoders(EncodersModel* model,
-                     wpi::StringRef noneMsg = "No encoders");
+                     std::string_view noneMsg = "No encoders");
 
 }  // namespace glass
diff --git a/glass/src/lib/native/include/glass/hardware/Gyro.h b/glass/src/lib/native/include/glass/hardware/Gyro.h
index b60f340acf..d2bb09d2ac 100644
--- a/glass/src/lib/native/include/glass/hardware/Gyro.h
+++ b/glass/src/lib/native/include/glass/hardware/Gyro.h
@@ -4,9 +4,6 @@
 
 #pragma once
 
-#include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
-
 #include "glass/Model.h"
 
 namespace glass {
diff --git a/glass/src/lib/native/include/glass/hardware/PCM.h b/glass/src/lib/native/include/glass/hardware/PCM.h
index a825ada889..af8bde892e 100644
--- a/glass/src/lib/native/include/glass/hardware/PCM.h
+++ b/glass/src/lib/native/include/glass/hardware/PCM.h
@@ -4,8 +4,9 @@
 
 #pragma once
 
+#include <string_view>
+
 #include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
 
 #include "glass/Model.h"
 
@@ -49,7 +50,7 @@ class PCMsModel : public Model {
 
 bool DisplayPCMSolenoids(PCMModel* model, int index, bool outputsEnabled);
 void DisplayPCMsSolenoids(PCMsModel* model, bool outputsEnabled,
-                          wpi::StringRef noneMsg = "No solenoids");
+                          std::string_view noneMsg = "No solenoids");
 
 void DisplayCompressorDevice(PCMModel* model, int index, bool outputsEnabled);
 void DisplayCompressorDevice(CompressorModel* model, int index,
diff --git a/glass/src/lib/native/include/glass/hardware/PDP.h b/glass/src/lib/native/include/glass/hardware/PDP.h
index 8b4f38def4..c0d5c3f487 100644
--- a/glass/src/lib/native/include/glass/hardware/PDP.h
+++ b/glass/src/lib/native/include/glass/hardware/PDP.h
@@ -4,8 +4,9 @@
 
 #pragma once
 
+#include <string_view>
+
 #include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
 
 #include "glass/Model.h"
 
@@ -33,6 +34,6 @@ class PDPsModel : public Model {
 };
 
 void DisplayPDP(PDPModel* model, int index);
-void DisplayPDPs(PDPsModel* model, wpi::StringRef noneMsg = "No PDPs");
+void DisplayPDPs(PDPsModel* model, std::string_view noneMsg = "No PDPs");
 
 }  // namespace glass
diff --git a/glass/src/lib/native/include/glass/hardware/PWM.h b/glass/src/lib/native/include/glass/hardware/PWM.h
index 229e75172c..d8a6a4ed47 100644
--- a/glass/src/lib/native/include/glass/hardware/PWM.h
+++ b/glass/src/lib/native/include/glass/hardware/PWM.h
@@ -4,8 +4,9 @@
 
 #pragma once
 
+#include <string_view>
+
 #include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
 
 #include "glass/Model.h"
 
@@ -31,6 +32,6 @@ class PWMsModel : public Model {
 
 void DisplayPWM(PWMModel* model, int index, bool outputsEnabled);
 void DisplayPWMs(PWMsModel* model, bool outputsEnabled,
-                 wpi::StringRef noneMsg = "No PWM outputs");
+                 std::string_view noneMsg = "No PWM outputs");
 
 }  // namespace glass
diff --git a/glass/src/lib/native/include/glass/hardware/Relay.h b/glass/src/lib/native/include/glass/hardware/Relay.h
index 55d26a77ae..287c42b71b 100644
--- a/glass/src/lib/native/include/glass/hardware/Relay.h
+++ b/glass/src/lib/native/include/glass/hardware/Relay.h
@@ -4,8 +4,9 @@
 
 #pragma once
 
+#include <string_view>
+
 #include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
 
 #include "glass/Model.h"
 
@@ -30,6 +31,6 @@ class RelaysModel : public Model {
 
 void DisplayRelay(RelayModel* model, int index, bool outputsEnabled);
 void DisplayRelays(RelaysModel* model, bool outputsEnabled,
-                   wpi::StringRef noneMsg = "No relays");
+                   std::string_view noneMsg = "No relays");
 
 }  // namespace glass
diff --git a/glass/src/lib/native/include/glass/hardware/SpeedController.h b/glass/src/lib/native/include/glass/hardware/SpeedController.h
index 6151b65511..033f27dcd3 100644
--- a/glass/src/lib/native/include/glass/hardware/SpeedController.h
+++ b/glass/src/lib/native/include/glass/hardware/SpeedController.h
@@ -4,9 +4,6 @@
 
 #pragma once
 
-#include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
-
 #include "glass/Model.h"
 
 namespace glass {
diff --git a/glass/src/lib/native/include/glass/other/CommandScheduler.h b/glass/src/lib/native/include/glass/other/CommandScheduler.h
index 94dcd3205f..66b92b2e45 100644
--- a/glass/src/lib/native/include/glass/other/CommandScheduler.h
+++ b/glass/src/lib/native/include/glass/other/CommandScheduler.h
@@ -7,9 +7,6 @@
 #include <string>
 #include <vector>
 
-#include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
-
 #include "glass/Model.h"
 
 namespace glass {
diff --git a/glass/src/lib/native/include/glass/other/CommandSelector.h b/glass/src/lib/native/include/glass/other/CommandSelector.h
index 456817786a..e5126f2ad6 100644
--- a/glass/src/lib/native/include/glass/other/CommandSelector.h
+++ b/glass/src/lib/native/include/glass/other/CommandSelector.h
@@ -4,9 +4,6 @@
 
 #pragma once
 
-#include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
-
 #include "glass/Model.h"
 
 namespace glass {
diff --git a/glass/src/lib/native/include/glass/other/Drive.h b/glass/src/lib/native/include/glass/other/Drive.h
index 33f8687362..c9695829f2 100644
--- a/glass/src/lib/native/include/glass/other/Drive.h
+++ b/glass/src/lib/native/include/glass/other/Drive.h
@@ -6,11 +6,10 @@
 
 #include <functional>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
-#include <wpi/StringRef.h>
-
 #include "glass/Model.h"
 
 struct ImVec2;
@@ -24,7 +23,7 @@ class DriveModel : public Model {
     DataSource* percent;
     std::function<void(double)> setter;
 
-    WheelInfo(wpi::StringRef name, DataSource* percent,
+    WheelInfo(std::string_view name, DataSource* percent,
               std::function<void(double)> setter)
         : name(name), percent(percent), setter(std::move(setter)) {}
   };
diff --git a/glass/src/lib/native/include/glass/other/FMS.h b/glass/src/lib/native/include/glass/other/FMS.h
index 2d19c3f4c2..1e0f8efcfc 100644
--- a/glass/src/lib/native/include/glass/other/FMS.h
+++ b/glass/src/lib/native/include/glass/other/FMS.h
@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include <wpi/StringRef.h>
+#include <string_view>
 
 #include "glass/Model.h"
 
@@ -27,7 +27,7 @@ class FMSModel : public Model {
   virtual DataSource* GetEnabledData() = 0;
   virtual DataSource* GetTestData() = 0;
   virtual DataSource* GetAutonomousData() = 0;
-  virtual wpi::StringRef GetGameSpecificMessage(
+  virtual std::string_view GetGameSpecificMessage(
       wpi::SmallVectorImpl<char>& buf) = 0;
 
   virtual void SetFmsAttached(bool val) = 0;
diff --git a/glass/src/lib/native/include/glass/other/Field2D.h b/glass/src/lib/native/include/glass/other/Field2D.h
index 35d188a97d..c9944deff3 100644
--- a/glass/src/lib/native/include/glass/other/Field2D.h
+++ b/glass/src/lib/native/include/glass/other/Field2D.h
@@ -4,14 +4,14 @@
 
 #pragma once
 
+#include <string_view>
+
 #include <frc/geometry/Pose2d.h>
 #include <frc/geometry/Rotation2d.h>
 #include <frc/geometry/Translation2d.h>
 #include <imgui.h>
 #include <wpi/ArrayRef.h>
 #include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 
 #include "glass/Model.h"
 #include "glass/View.h"
@@ -31,10 +31,10 @@ class FieldObjectModel : public Model {
 
 class Field2DModel : public Model {
  public:
-  virtual FieldObjectModel* AddFieldObject(const wpi::Twine& name) = 0;
-  virtual void RemoveFieldObject(const wpi::Twine& name) = 0;
+  virtual FieldObjectModel* AddFieldObject(std::string_view name) = 0;
+  virtual void RemoveFieldObject(std::string_view name) = 0;
   virtual void ForEachFieldObject(
-      wpi::function_ref<void(FieldObjectModel& model, wpi::StringRef name)>
+      wpi::function_ref<void(FieldObjectModel& model, std::string_view name)>
           func) = 0;
 };
 
diff --git a/glass/src/lib/native/include/glass/other/Log.h b/glass/src/lib/native/include/glass/other/Log.h
index ddaadaf918..3d9c59b669 100644
--- a/glass/src/lib/native/include/glass/other/Log.h
+++ b/glass/src/lib/native/include/glass/other/Log.h
@@ -5,10 +5,9 @@
 #pragma once
 
 #include <string>
+#include <string_view>
 #include <vector>
 
-#include <wpi/Twine.h>
-
 #include "glass/View.h"
 
 namespace glass {
@@ -20,7 +19,7 @@ class LogData {
   explicit LogData(size_t maxLines = 10000);
 
   void Clear();
-  void Append(const wpi::Twine& msg);
+  void Append(std::string_view msg);
   const std::string& GetBuffer();
 
  private:
diff --git a/glass/src/lib/native/include/glass/other/Plot.h b/glass/src/lib/native/include/glass/other/Plot.h
index 2ffc3da9c0..f7b196dcc2 100644
--- a/glass/src/lib/native/include/glass/other/Plot.h
+++ b/glass/src/lib/native/include/glass/other/Plot.h
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#include <string_view>
+
 #include "glass/WindowManager.h"
 #include "glass/support/IniSaverBase.h"
 
@@ -11,7 +13,7 @@ namespace glass {
 
 class PlotProvider : private WindowManager {
  public:
-  explicit PlotProvider(const wpi::Twine& iniName);
+  explicit PlotProvider(std::string_view iniName);
   ~PlotProvider() override;
 
   void GlobalInit() override;
@@ -35,7 +37,7 @@ class PlotProvider : private WindowManager {
 
   class IniSaver : public IniSaverBase {
    public:
-    explicit IniSaver(const wpi::Twine& typeName, PlotProvider* provider,
+    explicit IniSaver(std::string_view typeName, PlotProvider* provider,
                       bool forSeries);
 
     void* IniReadOpen(const char* name) override;
diff --git a/glass/src/lib/native/include/glass/other/StringChooser.h b/glass/src/lib/native/include/glass/other/StringChooser.h
index 6f0aa26dea..692eb7ca43 100644
--- a/glass/src/lib/native/include/glass/other/StringChooser.h
+++ b/glass/src/lib/native/include/glass/other/StringChooser.h
@@ -5,10 +5,10 @@
 #pragma once
 
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <wpi/ArrayRef.h>
-#include <wpi/StringRef.h>
 
 #include "glass/Model.h"
 
@@ -21,9 +21,9 @@ class StringChooserModel : public Model {
   virtual const std::string& GetActive() = 0;
   virtual const std::vector<std::string>& GetOptions() = 0;
 
-  virtual void SetDefault(wpi::StringRef val) = 0;
-  virtual void SetSelected(wpi::StringRef val) = 0;
-  virtual void SetActive(wpi::StringRef val) = 0;
+  virtual void SetDefault(std::string_view val) = 0;
+  virtual void SetSelected(std::string_view val) = 0;
+  virtual void SetActive(std::string_view val) = 0;
   virtual void SetOptions(wpi::ArrayRef<std::string> val) = 0;
 };
 
diff --git a/glass/src/lib/native/include/glass/other/Subsystem.h b/glass/src/lib/native/include/glass/other/Subsystem.h
index 89f06178cb..db79db583b 100644
--- a/glass/src/lib/native/include/glass/other/Subsystem.h
+++ b/glass/src/lib/native/include/glass/other/Subsystem.h
@@ -4,9 +4,6 @@
 
 #pragma once
 
-#include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
-
 #include "glass/Model.h"
 
 namespace glass {
diff --git a/glass/src/lib/native/include/glass/support/IniSaver.h b/glass/src/lib/native/include/glass/support/IniSaver.h
index 1312c0d517..a3aa3d0997 100644
--- a/glass/src/lib/native/include/glass/support/IniSaver.h
+++ b/glass/src/lib/native/include/glass/support/IniSaver.h
@@ -4,9 +4,10 @@
 
 #pragma once
 
+#include <string_view>
+
 #include <imgui.h>
 #include <wpi/DenseMap.h>
-#include <wpi/Twine.h>
 
 #include "glass/support/IniSaverBase.h"
 
@@ -15,7 +16,7 @@ namespace glass {
 template <typename Info>
 class IniSaver : public IniSaverBase {
  public:
-  explicit IniSaver(const wpi::Twine& typeName,
+  explicit IniSaver(std::string_view typeName,
                     IniSaverBackend* backend = nullptr)
       : IniSaverBase(typeName, backend) {}
 
diff --git a/glass/src/lib/native/include/glass/support/IniSaver.inc b/glass/src/lib/native/include/glass/support/IniSaver.inc
index 48f43973af..42efb85ba2 100644
--- a/glass/src/lib/native/include/glass/support/IniSaver.inc
+++ b/glass/src/lib/native/include/glass/support/IniSaver.inc
@@ -4,7 +4,9 @@
 
 #pragma once
 
-#include <wpi/StringRef.h>
+#include <string_view>
+
+#include <wpi/StringExtras.h>
 
 #include "glass/support/IniSaver.h"
 
@@ -12,21 +14,18 @@ namespace glass {
 
 template <typename Info>
 void* IniSaver<Info>::IniReadOpen(const char* name) {
-  int num;
-  if (wpi::StringRef{name}.getAsInteger(10, num)) {
+  if (auto num = wpi::parse_integer<int>(name, 10)) {
+    return &m_map[num.value()];
+  } else {
     return nullptr;
   }
-  return &m_map[num];
 }
 
 template <typename Info>
-void IniSaver<Info>::IniReadLine(void* entry, const char* lineStr) {
+void IniSaver<Info>::IniReadLine(void* entry, const char* line) {
   auto element = static_cast<Info*>(entry);
-  wpi::StringRef line{lineStr};
-  auto [name, value] = line.split('=');
-  name = name.trim();
-  value = value.trim();
-  element->ReadIni(name, value);
+  auto [name, value] = wpi::split(line, '=');
+  element->ReadIni(wpi::trim(name), wpi::trim(value));
 }
 
 template <typename Info>
diff --git a/glass/src/lib/native/include/glass/support/IniSaverBase.h b/glass/src/lib/native/include/glass/support/IniSaverBase.h
index e713ffc288..85ae1e3973 100644
--- a/glass/src/lib/native/include/glass/support/IniSaverBase.h
+++ b/glass/src/lib/native/include/glass/support/IniSaverBase.h
@@ -5,9 +5,9 @@
 #pragma once
 
 #include <string>
+#include <string_view>
 
 #include <imgui.h>
-#include <wpi/Twine.h>
 
 namespace glass {
 
@@ -22,7 +22,7 @@ class IniSaverBackend {
 
 class IniSaverBase {
  public:
-  explicit IniSaverBase(const wpi::Twine& typeName,
+  explicit IniSaverBase(std::string_view typeName,
                         IniSaverBackend* backend = nullptr);
   virtual ~IniSaverBase();
 
diff --git a/glass/src/lib/native/include/glass/support/IniSaverInfo.h b/glass/src/lib/native/include/glass/support/IniSaverInfo.h
index 957655ec75..2014e9d28b 100644
--- a/glass/src/lib/native/include/glass/support/IniSaverInfo.h
+++ b/glass/src/lib/native/include/glass/support/IniSaverInfo.h
@@ -4,9 +4,9 @@
 
 #pragma once
 
+#include <string_view>
+
 #include <imgui.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 
 namespace glass {
 
@@ -15,7 +15,7 @@ class NameInfo {
   NameInfo() { m_name[0] = '\0'; }
 
   bool HasName() const { return m_name[0] != '\0'; }
-  void SetName(const wpi::Twine& name);
+  void SetName(std::string_view name);
   const char* GetName() const { return m_name; }
   void GetName(char* buf, size_t size, const char* defaultName) const;
   void GetName(char* buf, size_t size, const char* defaultName,
@@ -28,7 +28,7 @@ class NameInfo {
   void GetLabel(char* buf, size_t size, const char* defaultName, int index,
                 int index2) const;
 
-  bool ReadIni(wpi::StringRef name, wpi::StringRef value);
+  bool ReadIni(std::string_view name, std::string_view value);
   void WriteIni(ImGuiTextBuffer* out);
   void PushEditNameId(int index);
   void PushEditNameId(const char* name);
@@ -47,7 +47,7 @@ class OpenInfo {
 
   bool IsOpen() const { return m_open; }
   void SetOpen(bool open) { m_open = open; }
-  bool ReadIni(wpi::StringRef name, wpi::StringRef value);
+  bool ReadIni(std::string_view name, std::string_view value);
   void WriteIni(ImGuiTextBuffer* out);
 
  private:
@@ -56,7 +56,7 @@ class OpenInfo {
 
 class NameOpenInfo : public NameInfo, public OpenInfo {
  public:
-  bool ReadIni(wpi::StringRef name, wpi::StringRef value);
+  bool ReadIni(std::string_view name, std::string_view value);
   void WriteIni(ImGuiTextBuffer* out);
 };
 
diff --git a/glass/src/lib/native/include/glass/support/IniSaverString.h b/glass/src/lib/native/include/glass/support/IniSaverString.h
index 9ac3d70d55..4134219433 100644
--- a/glass/src/lib/native/include/glass/support/IniSaverString.h
+++ b/glass/src/lib/native/include/glass/support/IniSaverString.h
@@ -4,12 +4,11 @@
 
 #pragma once
 
+#include <string_view>
 #include <utility>
 
 #include <imgui.h>
 #include <wpi/StringMap.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 
 #include "glass/support/IniSaverBase.h"
 
@@ -18,28 +17,28 @@ namespace glass {
 template <typename Info>
 class IniSaverString : public IniSaverBase {
  public:
-  explicit IniSaverString(const wpi::Twine& typeName,
+  explicit IniSaverString(std::string_view typeName,
                           IniSaverBackend* backend = nullptr)
       : IniSaverBase(typeName, backend) {}
 
   // pass through useful functions to map
-  Info& operator[](wpi::StringRef key) { return m_map[key]; }
+  Info& operator[](std::string_view key) { return m_map[key]; }
 
   template <typename... ArgsTy>
-  auto try_emplace(wpi::StringRef key, ArgsTy&&... args) {
+  auto try_emplace(std::string_view key, ArgsTy&&... args) {
     return m_map.try_emplace(key, std::forward<ArgsTy>(args)...);
   }
 
   void erase(typename wpi::StringMap<Info>::iterator it) { m_map.erase(it); }
-  auto erase(wpi::StringRef key) { return m_map.erase(key); }
+  auto erase(std::string_view key) { return m_map.erase(key); }
 
   auto begin() { return m_map.begin(); }
   auto end() { return m_map.end(); }
-  auto find(wpi::StringRef key) { return m_map.find(key); }
+  auto find(std::string_view key) { return m_map.find(key); }
 
   auto begin() const { return m_map.begin(); }
   auto end() const { return m_map.end(); }
-  auto find(wpi::StringRef key) const { return m_map.find(key); }
+  auto find(std::string_view key) const { return m_map.find(key); }
 
   bool empty() const { return m_map.empty(); }
 
diff --git a/glass/src/lib/native/include/glass/support/IniSaverString.inc b/glass/src/lib/native/include/glass/support/IniSaverString.inc
index 6ca76dde8e..0d18d29011 100644
--- a/glass/src/lib/native/include/glass/support/IniSaverString.inc
+++ b/glass/src/lib/native/include/glass/support/IniSaverString.inc
@@ -4,7 +4,9 @@
 
 #pragma once
 
-#include <wpi/StringRef.h>
+#include <string_view>
+
+#include <wpi/StringExtras.h>
 
 #include "glass/support/IniSaverString.h"
 
@@ -16,13 +18,10 @@ void* IniSaverString<Info>::IniReadOpen(const char* name) {
 }
 
 template <typename Info>
-void IniSaverString<Info>::IniReadLine(void* entry, const char* lineStr) {
+void IniSaverString<Info>::IniReadLine(void* entry, const char* line) {
   auto element = static_cast<Info*>(entry);
-  wpi::StringRef line{lineStr};
-  auto [name, value] = line.split('=');
-  name = name.trim();
-  value = value.trim();
-  element->ReadIni(name, value);
+  auto [name, value] = wpi::split(line, '=');
+  element->ReadIni(wpi::trim(name), wpi::trim(value));
 }
 
 template <typename Info>
diff --git a/glass/src/lib/native/include/glass/support/IniSaverVector.h b/glass/src/lib/native/include/glass/support/IniSaverVector.h
index 86b2bbc1ff..e2e57cec39 100644
--- a/glass/src/lib/native/include/glass/support/IniSaverVector.h
+++ b/glass/src/lib/native/include/glass/support/IniSaverVector.h
@@ -4,10 +4,10 @@
 
 #pragma once
 
+#include <string_view>
 #include <vector>
 
 #include <imgui.h>
-#include <wpi/Twine.h>
 
 #include "glass/support/IniSaverBase.h"
 
@@ -16,7 +16,7 @@ namespace glass {
 template <typename Info>
 class IniSaverVector : public std::vector<Info>, public IniSaverBase {
  public:
-  explicit IniSaverVector(const wpi::Twine& typeName,
+  explicit IniSaverVector(std::string_view typeName,
                           IniSaverBackend* backend = nullptr)
       : IniSaverBase(typeName, backend) {}
 
diff --git a/glass/src/lib/native/include/glass/support/IniSaverVector.inc b/glass/src/lib/native/include/glass/support/IniSaverVector.inc
index 0b48ab5781..a86b1161d2 100644
--- a/glass/src/lib/native/include/glass/support/IniSaverVector.inc
+++ b/glass/src/lib/native/include/glass/support/IniSaverVector.inc
@@ -4,7 +4,9 @@
 
 #pragma once
 
-#include <wpi/StringRef.h>
+#include <string_view>
+
+#include <wpi/StringExtras.h>
 
 #include "glass/support/IniSaverVector.h"
 
@@ -12,24 +14,21 @@ namespace glass {
 
 template <typename Info>
 void* IniSaverVector<Info>::IniReadOpen(const char* name) {
-  unsigned int num;
-  if (wpi::StringRef{name}.getAsInteger(10, num)) {
+  if (auto num = wpi::parse_integer<unsigned int>(name, 10)) {
+    if (num.value() >= this->size()) {
+      this->resize(num.value() + 1);
+    }
+    return &(*this)[num.value()];
+  } else {
     return nullptr;
   }
-  if (num >= this->size()) {
-    this->resize(num + 1);
-  }
-  return &(*this)[num];
 }
 
 template <typename Info>
-void IniSaverVector<Info>::IniReadLine(void* entry, const char* lineStr) {
+void IniSaverVector<Info>::IniReadLine(void* entry, const char* line) {
   auto element = static_cast<Info*>(entry);
-  wpi::StringRef line{lineStr};
-  auto [name, value] = line.split('=');
-  name = name.trim();
-  value = value.trim();
-  element->ReadIni(name, value);
+  auto [name, value] = wpi::split(line, '=');
+  element->ReadIni(wpi::trim(name), wpi::trim(value));
 }
 
 template <typename Info>
diff --git a/glass/src/libnt/native/cpp/NTCommandScheduler.cpp b/glass/src/libnt/native/cpp/NTCommandScheduler.cpp
index 857e0df16d..4d4e39394e 100644
--- a/glass/src/libnt/native/cpp/NTCommandScheduler.cpp
+++ b/glass/src/libnt/native/cpp/NTCommandScheduler.cpp
@@ -4,21 +4,22 @@
 
 #include "glass/networktables/NTCommandScheduler.h"
 
-#include <iostream>
+#include <fmt/format.h>
+#include <wpi/StringExtras.h>
 
 using namespace glass;
 
-NTCommandSchedulerModel::NTCommandSchedulerModel(wpi::StringRef path)
+NTCommandSchedulerModel::NTCommandSchedulerModel(std::string_view path)
     : NTCommandSchedulerModel(nt::GetDefaultInstance(), path) {}
 
 NTCommandSchedulerModel::NTCommandSchedulerModel(NT_Inst instance,
-                                                 wpi::StringRef path)
+                                                 std::string_view path)
     : m_nt(instance),
-      m_name(m_nt.GetEntry(path + "/.name")),
-      m_commands(m_nt.GetEntry(path + "/Names")),
-      m_ids(m_nt.GetEntry(path + "/Ids")),
-      m_cancel(m_nt.GetEntry(path + "/Cancel")),
-      m_nameValue(path.rsplit('/').second) {
+      m_name(m_nt.GetEntry(fmt::format("{}/.name", path))),
+      m_commands(m_nt.GetEntry(fmt::format("{}/Names", path))),
+      m_ids(m_nt.GetEntry(fmt::format("{}/Ids", path))),
+      m_cancel(m_nt.GetEntry(fmt::format("{}/Cancel", path))),
+      m_nameValue(wpi::rsplit(path, '/').second) {
   m_nt.AddListener(m_name);
   m_nt.AddListener(m_commands);
   m_nt.AddListener(m_ids);
diff --git a/glass/src/libnt/native/cpp/NTCommandSelector.cpp b/glass/src/libnt/native/cpp/NTCommandSelector.cpp
index bf9a399a35..efcbac2046 100644
--- a/glass/src/libnt/native/cpp/NTCommandSelector.cpp
+++ b/glass/src/libnt/native/cpp/NTCommandSelector.cpp
@@ -4,18 +4,21 @@
 
 #include "glass/networktables/NTCommandSelector.h"
 
+#include <fmt/format.h>
+#include <wpi/StringExtras.h>
+
 using namespace glass;
 
-NTCommandSelectorModel::NTCommandSelectorModel(wpi::StringRef path)
+NTCommandSelectorModel::NTCommandSelectorModel(std::string_view path)
     : NTCommandSelectorModel(nt::GetDefaultInstance(), path) {}
 
 NTCommandSelectorModel::NTCommandSelectorModel(NT_Inst instance,
-                                               wpi::StringRef path)
+                                               std::string_view path)
     : m_nt(instance),
-      m_running(m_nt.GetEntry(path + "/running")),
-      m_name(m_nt.GetEntry(path + "/.name")),
-      m_runningData("NTCmd:" + path),
-      m_nameValue(path.rsplit('/').second) {
+      m_running(m_nt.GetEntry(fmt::format("{}/running", path))),
+      m_name(m_nt.GetEntry(fmt::format("{}/.name", path))),
+      m_runningData(fmt::format("NTCmd:{}", path)),
+      m_nameValue(wpi::rsplit(path, '/').second) {
   m_runningData.SetDigital(true);
   m_nt.AddListener(m_running);
   m_nt.AddListener(m_name);
diff --git a/glass/src/libnt/native/cpp/NTDifferentialDrive.cpp b/glass/src/libnt/native/cpp/NTDifferentialDrive.cpp
index 39fe335064..b44ea07d7d 100644
--- a/glass/src/libnt/native/cpp/NTDifferentialDrive.cpp
+++ b/glass/src/libnt/native/cpp/NTDifferentialDrive.cpp
@@ -4,24 +4,26 @@
 
 #include "glass/networktables/NTDifferentialDrive.h"
 
+#include <fmt/format.h>
 #include <imgui.h>
 #include <wpi/MathExtras.h>
+#include <wpi/StringExtras.h>
 
 using namespace glass;
 
-NTDifferentialDriveModel::NTDifferentialDriveModel(wpi::StringRef path)
+NTDifferentialDriveModel::NTDifferentialDriveModel(std::string_view path)
     : NTDifferentialDriveModel(nt::GetDefaultInstance(), path) {}
 
 NTDifferentialDriveModel::NTDifferentialDriveModel(NT_Inst instance,
-                                                   wpi::StringRef path)
+                                                   std::string_view path)
     : m_nt(instance),
-      m_name(m_nt.GetEntry(path + "/.name")),
-      m_controllable(m_nt.GetEntry(path + "/.controllable")),
-      m_lPercent(m_nt.GetEntry(path + "/Left Motor Speed")),
-      m_rPercent(m_nt.GetEntry(path + "/Right Motor Speed")),
-      m_nameValue(path.rsplit('/').second),
-      m_lPercentData("NTDiffDriveL:" + path),
-      m_rPercentData("NTDiffDriveR:" + path) {
+      m_name(m_nt.GetEntry(fmt::format("{}/.name", path))),
+      m_controllable(m_nt.GetEntry(fmt::format("{}/.controllable", path))),
+      m_lPercent(m_nt.GetEntry(fmt::format("{}/Left Motor Speed", path))),
+      m_rPercent(m_nt.GetEntry(fmt::format("{}/Right Motor Speed", path))),
+      m_nameValue(wpi::rsplit(path, '/').second),
+      m_lPercentData(fmt::format("NTDiffDriveL:{}", path)),
+      m_rPercentData(fmt::format("NTDiffDriveR:{}", path)) {
   m_nt.AddListener(m_name);
   m_nt.AddListener(m_controllable);
   m_nt.AddListener(m_lPercent);
diff --git a/glass/src/libnt/native/cpp/NTDigitalInput.cpp b/glass/src/libnt/native/cpp/NTDigitalInput.cpp
index a823dbbd25..5de6c2954e 100644
--- a/glass/src/libnt/native/cpp/NTDigitalInput.cpp
+++ b/glass/src/libnt/native/cpp/NTDigitalInput.cpp
@@ -4,19 +4,20 @@
 
 #include "glass/networktables/NTDigitalInput.h"
 
-#include <wpi/Twine.h>
+#include <fmt/format.h>
+#include <wpi/StringExtras.h>
 
 using namespace glass;
 
-NTDigitalInputModel::NTDigitalInputModel(wpi::StringRef path)
+NTDigitalInputModel::NTDigitalInputModel(std::string_view path)
     : NTDigitalInputModel{nt::GetDefaultInstance(), path} {}
 
-NTDigitalInputModel::NTDigitalInputModel(NT_Inst inst, wpi::StringRef path)
+NTDigitalInputModel::NTDigitalInputModel(NT_Inst inst, std::string_view path)
     : m_nt{inst},
-      m_value{m_nt.GetEntry(path + "/Value")},
-      m_name{m_nt.GetEntry(path + "/.name")},
-      m_valueData{"NT_DIn:" + path},
-      m_nameValue{path.rsplit('/').second} {
+      m_value{m_nt.GetEntry(fmt::format("{}/Value", path))},
+      m_name{m_nt.GetEntry(fmt::format("{}/.name", path))},
+      m_valueData{fmt::format("NT_DIn:{}", path)},
+      m_nameValue{wpi::rsplit(path, '/').second} {
   m_nt.AddListener(m_value);
   m_nt.AddListener(m_name);
 
diff --git a/glass/src/libnt/native/cpp/NTDigitalOutput.cpp b/glass/src/libnt/native/cpp/NTDigitalOutput.cpp
index ca260b548d..a09d424446 100644
--- a/glass/src/libnt/native/cpp/NTDigitalOutput.cpp
+++ b/glass/src/libnt/native/cpp/NTDigitalOutput.cpp
@@ -4,19 +4,19 @@
 
 #include "glass/networktables/NTDigitalOutput.h"
 
-#include <wpi/Twine.h>
+#include <fmt/format.h>
 
 using namespace glass;
 
-NTDigitalOutputModel::NTDigitalOutputModel(wpi::StringRef path)
+NTDigitalOutputModel::NTDigitalOutputModel(std::string_view path)
     : NTDigitalOutputModel{nt::GetDefaultInstance(), path} {}
 
-NTDigitalOutputModel::NTDigitalOutputModel(NT_Inst inst, wpi::StringRef path)
+NTDigitalOutputModel::NTDigitalOutputModel(NT_Inst inst, std::string_view path)
     : m_nt{inst},
-      m_value{m_nt.GetEntry(path + "/Value")},
-      m_name{m_nt.GetEntry(path + "/.name")},
-      m_controllable{m_nt.GetEntry(path + "/.controllable")},
-      m_valueData{"NT_DOut:" + path} {
+      m_value{m_nt.GetEntry(fmt::format("{}/Value", path))},
+      m_name{m_nt.GetEntry(fmt::format("{}/.name", path))},
+      m_controllable{m_nt.GetEntry(fmt::format("{}/.controllable", path))},
+      m_valueData{fmt::format("NT_DOut:{}", path)} {
   m_nt.AddListener(m_value);
   m_nt.AddListener(m_name);
   m_nt.AddListener(m_controllable);
diff --git a/glass/src/libnt/native/cpp/NTFMS.cpp b/glass/src/libnt/native/cpp/NTFMS.cpp
index f1dc2eede9..1f54803fc7 100644
--- a/glass/src/libnt/native/cpp/NTFMS.cpp
+++ b/glass/src/libnt/native/cpp/NTFMS.cpp
@@ -6,27 +6,28 @@
 
 #include <stdint.h>
 
-#include <wpi/Twine.h>
+#include <fmt/format.h>
 #include <wpi/timestamp.h>
 
 using namespace glass;
 
-NTFMSModel::NTFMSModel(wpi::StringRef path)
+NTFMSModel::NTFMSModel(std::string_view path)
     : NTFMSModel{nt::GetDefaultInstance(), path} {}
 
-NTFMSModel::NTFMSModel(NT_Inst inst, wpi::StringRef path)
+NTFMSModel::NTFMSModel(NT_Inst inst, std::string_view path)
     : m_nt{inst},
-      m_gameSpecificMessage{m_nt.GetEntry(path + "/GameSpecificMessage")},
-      m_alliance{m_nt.GetEntry(path + "/IsRedAlliance")},
-      m_station{m_nt.GetEntry(path + "/StationNumber")},
-      m_controlWord{m_nt.GetEntry(path + "/FMSControlData")},
-      m_fmsAttached{"NT_FMS:FMSAttached:" + path},
-      m_dsAttached{"NT_FMS:DSAttached:" + path},
-      m_allianceStationId{"NT_FMS:AllianceStationID:" + path},
-      m_estop{"NT_FMS:EStop:" + path},
-      m_enabled{"NT_FMS:RobotEnabled:" + path},
-      m_test{"NT_FMS:TestMode:" + path},
-      m_autonomous{"NT_FMS:AutonomousMode:" + path} {
+      m_gameSpecificMessage{
+          m_nt.GetEntry(fmt::format("{}/GameSpecificMessage", path))},
+      m_alliance{m_nt.GetEntry(fmt::format("{}/IsRedAlliance", path))},
+      m_station{m_nt.GetEntry(fmt::format("{}/StationNumber", path))},
+      m_controlWord{m_nt.GetEntry(fmt::format("{}/FMSControlData", path))},
+      m_fmsAttached{fmt::format("NT_FMS:FMSAttached:{}", path)},
+      m_dsAttached{fmt::format("NT_FMS:DSAttached:{}", path)},
+      m_allianceStationId{fmt::format("NT_FMS:AllianceStationID:{}", path)},
+      m_estop{fmt::format("NT_FMS:EStop:{}", path)},
+      m_enabled{fmt::format("NT_FMS:RobotEnabled:{}", path)},
+      m_test{fmt::format("NT_FMS:TestMode:{}", path)},
+      m_autonomous{fmt::format("NT_FMS:AutonomousMode:{}", path)} {
   m_nt.AddListener(m_alliance);
   m_nt.AddListener(m_station);
   m_nt.AddListener(m_controlWord);
@@ -39,7 +40,7 @@ NTFMSModel::NTFMSModel(NT_Inst inst, wpi::StringRef path)
   m_autonomous.SetDigital(true);
 }
 
-wpi::StringRef NTFMSModel::GetGameSpecificMessage(
+std::string_view NTFMSModel::GetGameSpecificMessage(
     wpi::SmallVectorImpl<char>& buf) {
   buf.clear();
   auto value = nt::GetEntryValue(m_gameSpecificMessage);
@@ -47,7 +48,7 @@ wpi::StringRef NTFMSModel::GetGameSpecificMessage(
     auto str = value->GetString();
     buf.append(str.begin(), str.end());
   }
-  return wpi::StringRef{buf.data(), buf.size()};
+  return std::string_view{buf.data(), buf.size()};
 }
 
 void NTFMSModel::Update() {
diff --git a/glass/src/libnt/native/cpp/NTField2D.cpp b/glass/src/libnt/native/cpp/NTField2D.cpp
index 89f6a639e5..5c0c9542f5 100644
--- a/glass/src/libnt/native/cpp/NTField2D.cpp
+++ b/glass/src/libnt/native/cpp/NTField2D.cpp
@@ -7,17 +7,18 @@
 #include <algorithm>
 #include <vector>
 
+#include <fmt/format.h>
 #include <ntcore_cpp.h>
 #include <wpi/Endian.h>
 #include <wpi/MathExtras.h>
-#include <wpi/SmallString.h>
 #include <wpi/SmallVector.h>
+#include <wpi/StringExtras.h>
 
 using namespace glass;
 
 class NTField2DModel::ObjectModel : public FieldObjectModel {
  public:
-  ObjectModel(wpi::StringRef name, NT_Entry entry)
+  ObjectModel(std::string_view name, NT_Entry entry)
       : m_name{name}, m_entry{entry} {}
 
   const char* GetName() const override { return m_name.c_str(); }
@@ -63,7 +64,7 @@ void NTField2DModel::ObjectModel::NTUpdate(const nt::Value& value) {
     }
   } else if (value.IsRaw()) {
     // treat it simply as an array of doubles
-    wpi::StringRef data = value.GetRaw();
+    std::string_view data = value.GetRaw();
 
     // must be triples of doubles
     auto size = data.size();
@@ -71,7 +72,7 @@ void NTField2DModel::ObjectModel::NTUpdate(const nt::Value& value) {
       return;
     }
     m_poses.resize(size / (3 * 8));
-    const char* p = data.begin();
+    const char* p = data.data();
     for (size_t i = 0; i < size / (3 * 8); ++i) {
       double x = wpi::BitsToDouble(
           wpi::support::endian::readNext<uint64_t, wpi::support::big,
@@ -115,8 +116,8 @@ void NTField2DModel::ObjectModel::UpdateNT() {
           p, wpi::DoubleToBits(pose.Rotation().Degrees().to<double>()));
       p += 8;
     }
-    nt::SetEntryTypeValue(
-        m_entry, nt::Value::MakeRaw(wpi::StringRef{arr.data(), arr.size()}));
+    nt::SetEntryTypeValue(m_entry,
+                          nt::Value::MakeRaw({arr.data(), arr.size()}));
   }
 }
 
@@ -147,13 +148,13 @@ void NTField2DModel::ObjectModel::SetRotation(size_t i, frc::Rotation2d rot) {
   }
 }
 
-NTField2DModel::NTField2DModel(wpi::StringRef path)
+NTField2DModel::NTField2DModel(std::string_view path)
     : NTField2DModel{nt::GetDefaultInstance(), path} {}
 
-NTField2DModel::NTField2DModel(NT_Inst inst, wpi::StringRef path)
+NTField2DModel::NTField2DModel(NT_Inst inst, std::string_view path)
     : m_nt{inst},
-      m_path{(path + "/").str()},
-      m_name{m_nt.GetEntry(path + "/.name")} {
+      m_path{fmt::format("{}/", path)},
+      m_name{m_nt.GetEntry(fmt::format("{}/.name", path))} {
   m_nt.AddListener(m_path, NT_NOTIFY_LOCAL | NT_NOTIFY_NEW | NT_NOTIFY_DELETE |
                                NT_NOTIFY_UPDATE | NT_NOTIFY_IMMEDIATE);
 }
@@ -182,8 +183,9 @@ void NTField2DModel::Update() {
     }
 
     // handle create/delete
-    if (wpi::StringRef{event.name}.startswith(m_path)) {
-      auto name = wpi::StringRef{event.name}.drop_front(m_path.size());
+    std::string_view name = event.name;
+    if (wpi::starts_with(name, m_path)) {
+      name.remove_prefix(m_path.size());
       if (name.empty() || name[0] == '.') {
         continue;
       }
@@ -216,9 +218,8 @@ bool NTField2DModel::IsReadOnly() {
   return false;
 }
 
-FieldObjectModel* NTField2DModel::AddFieldObject(const wpi::Twine& name) {
-  wpi::SmallString<128> fullNameBuf;
-  wpi::StringRef fullName = (m_path + name).toStringRef(fullNameBuf);
+FieldObjectModel* NTField2DModel::AddFieldObject(std::string_view name) {
+  auto fullName = fmt::format("{}{}", m_path, name);
   auto [it, match] = Find(fullName);
   if (!match) {
     it = m_objects.emplace(
@@ -227,9 +228,8 @@ FieldObjectModel* NTField2DModel::AddFieldObject(const wpi::Twine& name) {
   return it->get();
 }
 
-void NTField2DModel::RemoveFieldObject(const wpi::Twine& name) {
-  wpi::SmallString<128> fullNameBuf;
-  auto [it, match] = Find((m_path + name).toStringRef(fullNameBuf));
+void NTField2DModel::RemoveFieldObject(std::string_view name) {
+  auto [it, match] = Find(fmt::format("{}{}", m_path, name));
   if (match) {
     nt::DeleteEntry((*it)->GetEntry());
     m_objects.erase(it);
@@ -237,19 +237,19 @@ void NTField2DModel::RemoveFieldObject(const wpi::Twine& name) {
 }
 
 void NTField2DModel::ForEachFieldObject(
-    wpi::function_ref<void(FieldObjectModel& model, wpi::StringRef name)>
+    wpi::function_ref<void(FieldObjectModel& model, std::string_view name)>
         func) {
   for (auto&& obj : m_objects) {
     if (obj->Exists()) {
-      func(*obj, wpi::StringRef{obj->GetName()}.drop_front(m_path.size()));
+      func(*obj, wpi::drop_front(obj->GetName(), m_path.size()));
     }
   }
 }
 
 std::pair<NTField2DModel::Objects::iterator, bool> NTField2DModel::Find(
-    wpi::StringRef fullName) {
+    std::string_view fullName) {
   auto it = std::lower_bound(
       m_objects.begin(), m_objects.end(), fullName,
-      [](const auto& e, wpi::StringRef name) { return e->GetName() < name; });
+      [](const auto& e, std::string_view name) { return e->GetName() < name; });
   return {it, it != m_objects.end() && (*it)->GetName() == fullName};
 }
diff --git a/glass/src/libnt/native/cpp/NTGyro.cpp b/glass/src/libnt/native/cpp/NTGyro.cpp
index e0af6a0480..7651d2c1ff 100644
--- a/glass/src/libnt/native/cpp/NTGyro.cpp
+++ b/glass/src/libnt/native/cpp/NTGyro.cpp
@@ -4,17 +4,20 @@
 
 #include "glass/networktables/NTGyro.h"
 
+#include <fmt/format.h>
+#include <wpi/StringExtras.h>
+
 using namespace glass;
 
-NTGyroModel::NTGyroModel(wpi::StringRef path)
+NTGyroModel::NTGyroModel(std::string_view path)
     : NTGyroModel(nt::GetDefaultInstance(), path) {}
 
-NTGyroModel::NTGyroModel(NT_Inst instance, wpi::StringRef path)
+NTGyroModel::NTGyroModel(NT_Inst instance, std::string_view path)
     : m_nt(instance),
-      m_angle(m_nt.GetEntry(path + "/Value")),
-      m_name(m_nt.GetEntry(path + "/.name")),
-      m_angleData("NT_Gyro:" + path),
-      m_nameValue(path.rsplit('/').second) {
+      m_angle(m_nt.GetEntry(fmt::format("{}/Value", path))),
+      m_name(m_nt.GetEntry(fmt::format("{}/.name", path))),
+      m_angleData(fmt::format("NT_Gyro:{}", path)),
+      m_nameValue(wpi::rsplit(path, '/').second) {
   m_nt.AddListener(m_angle);
   m_nt.AddListener(m_name);
 }
diff --git a/glass/src/libnt/native/cpp/NTMecanumDrive.cpp b/glass/src/libnt/native/cpp/NTMecanumDrive.cpp
index a071e5d517..28c0a6745c 100644
--- a/glass/src/libnt/native/cpp/NTMecanumDrive.cpp
+++ b/glass/src/libnt/native/cpp/NTMecanumDrive.cpp
@@ -4,27 +4,33 @@
 
 #include "glass/networktables/NTMecanumDrive.h"
 
+#include <fmt/format.h>
 #include <imgui.h>
 #include <wpi/MathExtras.h>
+#include <wpi/StringExtras.h>
 
 using namespace glass;
 
-NTMecanumDriveModel::NTMecanumDriveModel(wpi::StringRef path)
+NTMecanumDriveModel::NTMecanumDriveModel(std::string_view path)
     : NTMecanumDriveModel(nt::GetDefaultInstance(), path) {}
 
-NTMecanumDriveModel::NTMecanumDriveModel(NT_Inst instance, wpi::StringRef path)
+NTMecanumDriveModel::NTMecanumDriveModel(NT_Inst instance,
+                                         std::string_view path)
     : m_nt(instance),
-      m_name(m_nt.GetEntry(path + "/.name")),
-      m_controllable(m_nt.GetEntry(path + "/.controllable")),
-      m_flPercent(m_nt.GetEntry(path + "/Front Left Motor Speed")),
-      m_frPercent(m_nt.GetEntry(path + "/Front Right Motor Speed")),
-      m_rlPercent(m_nt.GetEntry(path + "/Rear Left Motor Speed")),
-      m_rrPercent(m_nt.GetEntry(path + "/Rear Right Motor Speed")),
-      m_nameValue(path.rsplit('/').second),
-      m_flPercentData("NTMcnmDriveFL:" + path),
-      m_frPercentData("NTMcnmDriveFR:" + path),
-      m_rlPercentData("NTMcnmDriveRL:" + path),
-      m_rrPercentData("NTMcnmDriveRR:" + path) {
+      m_name(m_nt.GetEntry(fmt::format("{}/.name", path))),
+      m_controllable(m_nt.GetEntry(fmt::format("{}/.controllable", path))),
+      m_flPercent(
+          m_nt.GetEntry(fmt::format("{}/Front Left Motor Speed", path))),
+      m_frPercent(
+          m_nt.GetEntry(fmt::format("{}/Front Right Motor Speed", path))),
+      m_rlPercent(m_nt.GetEntry(fmt::format("{}/Rear Left Motor Speed", path))),
+      m_rrPercent(
+          m_nt.GetEntry(fmt::format("{}/Rear Right Motor Speed", path))),
+      m_nameValue(wpi::rsplit(path, '/').second),
+      m_flPercentData(fmt::format("NTMcnmDriveFL:{}", path)),
+      m_frPercentData(fmt::format("NTMcnmDriveFR:{}", path)),
+      m_rlPercentData(fmt::format("NTMcnmDriveRL:{}", path)),
+      m_rrPercentData(fmt::format("NTMcnmDriveRR:{}", path)) {
   m_nt.AddListener(m_name);
   m_nt.AddListener(m_controllable);
   m_nt.AddListener(m_flPercent);
diff --git a/glass/src/libnt/native/cpp/NTMechanism2D.cpp b/glass/src/libnt/native/cpp/NTMechanism2D.cpp
index 99a17e3ef3..9c73af2532 100644
--- a/glass/src/libnt/native/cpp/NTMechanism2D.cpp
+++ b/glass/src/libnt/native/cpp/NTMechanism2D.cpp
@@ -5,25 +5,27 @@
 #include "glass/networktables/NTMechanism2D.h"
 
 #include <algorithm>
+#include <string_view>
 #include <vector>
 
+#include <fmt/format.h>
 #include <imgui.h>
 #include <ntcore_cpp.h>
+#include <wpi/StringExtras.h>
 
 #include "glass/other/Mechanism2D.h"
 
 using namespace glass;
 
 // Convert "#RRGGBB" hex color to ImU32 color
-static void ConvertColor(wpi::StringRef in, ImU32* out) {
+static void ConvertColor(std::string_view in, ImU32* out) {
   if (in.size() != 7 || in[0] != '#') {
     return;
   }
-  ImU32 val = 0;
-  if (in.drop_front().getAsInteger(16, val)) {
-    return;
+  if (auto v = wpi::parse_integer<ImU32>(wpi::drop_front(in), 16)) {
+    ImU32 val = v.value();
+    *out = IM_COL32((val >> 16) & 0xff, (val >> 8) & 0xff, val & 0xff, 255);
   }
-  *out = IM_COL32((val >> 16) & 0xff, (val >> 8) & 0xff, val & 0xff, 255);
 }
 
 namespace {
@@ -32,13 +34,13 @@ class NTMechanismObjectModel;
 
 class NTMechanismGroupImpl final {
  public:
-  NTMechanismGroupImpl(NT_Inst inst, const wpi::Twine& path,
-                       wpi::StringRef name)
-      : m_inst{inst}, m_path{path.str()}, m_name{name} {}
+  NTMechanismGroupImpl(NT_Inst inst, std::string_view path,
+                       std::string_view name)
+      : m_inst{inst}, m_path{path}, m_name{name} {}
 
   const char* GetName() const { return m_name.c_str(); }
   void ForEachObject(wpi::function_ref<void(MechanismObjectModel& model)> func);
-  void NTUpdate(const nt::EntryNotification& event, wpi::StringRef name);
+  void NTUpdate(const nt::EntryNotification& event, std::string_view name);
 
  protected:
   NT_Inst m_inst;
@@ -49,14 +51,14 @@ class NTMechanismGroupImpl final {
 
 class NTMechanismObjectModel final : public MechanismObjectModel {
  public:
-  NTMechanismObjectModel(NT_Inst inst, const wpi::Twine& path,
-                         wpi::StringRef name)
+  NTMechanismObjectModel(NT_Inst inst, std::string_view path,
+                         std::string_view name)
       : m_group{inst, path, name},
-        m_type{nt::GetEntry(inst, path + "/.type")},
-        m_color{nt::GetEntry(inst, path + "/color")},
-        m_weight{nt::GetEntry(inst, path + "/weight")},
-        m_angle{nt::GetEntry(inst, path + "/angle")},
-        m_length{nt::GetEntry(inst, path + "/length")} {}
+        m_type{nt::GetEntry(inst, fmt::format("{}/.type", path))},
+        m_color{nt::GetEntry(inst, fmt::format("{}/color", path))},
+        m_weight{nt::GetEntry(inst, fmt::format("{}/weight", path))},
+        m_angle{nt::GetEntry(inst, fmt::format("{}/angle", path))},
+        m_length{nt::GetEntry(inst, fmt::format("{}/length", path))} {}
 
   const char* GetName() const final { return m_group.GetName(); }
   void ForEachObject(
@@ -70,7 +72,7 @@ class NTMechanismObjectModel final : public MechanismObjectModel {
   frc::Rotation2d GetAngle() const final { return m_angleValue; }
   units::meter_t GetLength() const final { return m_lengthValue; }
 
-  bool NTUpdate(const nt::EntryNotification& event, wpi::StringRef childName);
+  bool NTUpdate(const nt::EntryNotification& event, std::string_view childName);
 
  private:
   NTMechanismGroupImpl m_group;
@@ -98,25 +100,26 @@ void NTMechanismGroupImpl::ForEachObject(
 }
 
 void NTMechanismGroupImpl::NTUpdate(const nt::EntryNotification& event,
-                                    wpi::StringRef name) {
+                                    std::string_view name) {
   if (name.empty()) {
     return;
   }
-  wpi::StringRef childName;
-  std::tie(name, childName) = name.split('/');
+  std::string_view childName;
+  std::tie(name, childName) = wpi::split(name, '/');
   if (childName.empty()) {
     return;
   }
 
   auto it = std::lower_bound(
       m_objects.begin(), m_objects.end(), name,
-      [](const auto& e, wpi::StringRef name) { return e->GetName() < name; });
+      [](const auto& e, std::string_view name) { return e->GetName() < name; });
   bool match = it != m_objects.end() && (*it)->GetName() == name;
 
   if (event.flags & NT_NOTIFY_NEW) {
     if (!match) {
-      it = m_objects.emplace(it, std::make_unique<NTMechanismObjectModel>(
-                                     m_inst, m_path + "/" + name, name));
+      it = m_objects.emplace(
+          it, std::make_unique<NTMechanismObjectModel>(
+                  m_inst, fmt::format("{}/{}", m_path, name), name));
       match = true;
     }
   }
@@ -128,7 +131,7 @@ void NTMechanismGroupImpl::NTUpdate(const nt::EntryNotification& event,
 }
 
 bool NTMechanismObjectModel::NTUpdate(const nt::EntryNotification& event,
-                                      wpi::StringRef childName) {
+                                      std::string_view childName) {
   if (event.entry == m_type) {
     if ((event.flags & NT_NOTIFY_DELETE) != 0) {
       return true;
@@ -160,10 +163,10 @@ bool NTMechanismObjectModel::NTUpdate(const nt::EntryNotification& event,
 
 class NTMechanism2DModel::RootModel final : public MechanismRootModel {
  public:
-  RootModel(NT_Inst inst, const wpi::Twine& path, wpi::StringRef name)
+  RootModel(NT_Inst inst, std::string_view path, std::string_view name)
       : m_group{inst, path, name},
-        m_x{nt::GetEntry(inst, path + "/x")},
-        m_y{nt::GetEntry(inst, path + "/y")} {}
+        m_x{nt::GetEntry(inst, fmt::format("{}/x", path))},
+        m_y{nt::GetEntry(inst, fmt::format("{}/y", path))} {}
 
   const char* GetName() const final { return m_group.GetName(); }
   void ForEachObject(
@@ -171,7 +174,7 @@ class NTMechanism2DModel::RootModel final : public MechanismRootModel {
     m_group.ForEachObject(func);
   }
 
-  bool NTUpdate(const nt::EntryNotification& event, wpi::StringRef childName);
+  bool NTUpdate(const nt::EntryNotification& event, std::string_view childName);
 
   frc::Translation2d GetPosition() const override { return m_pos; };
 
@@ -183,7 +186,7 @@ class NTMechanism2DModel::RootModel final : public MechanismRootModel {
 };
 
 bool NTMechanism2DModel::RootModel::NTUpdate(const nt::EntryNotification& event,
-                                             wpi::StringRef childName) {
+                                             std::string_view childName) {
   if ((event.flags & NT_NOTIFY_DELETE) != 0 &&
       (event.entry == m_x || event.entry == m_y)) {
     return true;
@@ -203,15 +206,15 @@ bool NTMechanism2DModel::RootModel::NTUpdate(const nt::EntryNotification& event,
   return false;
 }
 
-NTMechanism2DModel::NTMechanism2DModel(wpi::StringRef path)
+NTMechanism2DModel::NTMechanism2DModel(std::string_view path)
     : NTMechanism2DModel{nt::GetDefaultInstance(), path} {}
 
-NTMechanism2DModel::NTMechanism2DModel(NT_Inst inst, wpi::StringRef path)
+NTMechanism2DModel::NTMechanism2DModel(NT_Inst inst, std::string_view path)
     : m_nt{inst},
-      m_path{(path + "/").str()},
-      m_name{m_nt.GetEntry(path + "/.name")},
-      m_dimensions{m_nt.GetEntry(path + "/dims")},
-      m_bgColor{m_nt.GetEntry(path + "/backgroundColor")},
+      m_path{fmt::format("{}/", path)},
+      m_name{m_nt.GetEntry(fmt::format("{}/.name", path))},
+      m_dimensions{m_nt.GetEntry(fmt::format("{}/dims", path))},
+      m_bgColor{m_nt.GetEntry(fmt::format("{}/backgroundColor", path))},
       m_dimensionsValue{1_m, 1_m} {
   m_nt.AddListener(m_path, NT_NOTIFY_LOCAL | NT_NOTIFY_NEW | NT_NOTIFY_DELETE |
                                NT_NOTIFY_UPDATE | NT_NOTIFY_IMMEDIATE);
@@ -247,28 +250,30 @@ void NTMechanism2DModel::Update() {
       }
     }
 
-    if (wpi::StringRef{event.name}.startswith(m_path)) {
-      auto name = wpi::StringRef{event.name}.drop_front(m_path.size());
+    std::string_view name = event.name;
+    if (wpi::starts_with(name, m_path)) {
+      name.remove_prefix(m_path.size());
       if (name.empty() || name[0] == '.') {
         continue;
       }
-      wpi::StringRef childName;
-      std::tie(name, childName) = name.split('/');
+      std::string_view childName;
+      std::tie(name, childName) = wpi::split(name, '/');
       if (childName.empty()) {
         continue;
       }
 
       auto it = std::lower_bound(m_roots.begin(), m_roots.end(), name,
-                                 [](const auto& e, wpi::StringRef name) {
+                                 [](const auto& e, std::string_view name) {
                                    return e->GetName() < name;
                                  });
       bool match = it != m_roots.end() && (*it)->GetName() == name;
 
       if (event.flags & NT_NOTIFY_NEW) {
         if (!match) {
-          it =
-              m_roots.emplace(it, std::make_unique<RootModel>(
-                                      m_nt.GetInstance(), m_path + name, name));
+          it = m_roots.emplace(
+              it,
+              std::make_unique<RootModel>(
+                  m_nt.GetInstance(), fmt::format("{}{}", m_path, name), name));
           match = true;
         }
       }
diff --git a/glass/src/libnt/native/cpp/NTPIDController.cpp b/glass/src/libnt/native/cpp/NTPIDController.cpp
index fdea4fb451..7936057fab 100644
--- a/glass/src/libnt/native/cpp/NTPIDController.cpp
+++ b/glass/src/libnt/native/cpp/NTPIDController.cpp
@@ -4,25 +4,28 @@
 
 #include "glass/networktables/NTPIDController.h"
 
+#include <fmt/format.h>
+#include <wpi/StringExtras.h>
+
 using namespace glass;
 
-NTPIDControllerModel::NTPIDControllerModel(wpi::StringRef path)
+NTPIDControllerModel::NTPIDControllerModel(std::string_view path)
     : NTPIDControllerModel(nt::GetDefaultInstance(), path) {}
 
 NTPIDControllerModel::NTPIDControllerModel(NT_Inst instance,
-                                           wpi::StringRef path)
+                                           std::string_view path)
     : m_nt(instance),
-      m_name(m_nt.GetEntry(path + "/.name")),
-      m_controllable(m_nt.GetEntry(path + "/.controllable")),
-      m_p(m_nt.GetEntry(path + "/p")),
-      m_i(m_nt.GetEntry(path + "/i")),
-      m_d(m_nt.GetEntry(path + "/d")),
-      m_setpoint(m_nt.GetEntry(path + "/setpoint")),
-      m_pData("NTPIDCtrlP:" + path),
-      m_iData("NTPIDCtrlI:" + path),
-      m_dData("NTPIDCtrlD:" + path),
-      m_setpointData("NTPIDCtrlStpt:" + path),
-      m_nameValue(path.rsplit('/').second) {
+      m_name(m_nt.GetEntry(fmt::format("{}/.name", path))),
+      m_controllable(m_nt.GetEntry(fmt::format("{}/.controllable", path))),
+      m_p(m_nt.GetEntry(fmt::format("{}/p", path))),
+      m_i(m_nt.GetEntry(fmt::format("{}/i", path))),
+      m_d(m_nt.GetEntry(fmt::format("{}/d", path))),
+      m_setpoint(m_nt.GetEntry(fmt::format("{}/setpoint", path))),
+      m_pData(fmt::format("NTPIDCtrlP:{}", path)),
+      m_iData(fmt::format("NTPIDCtrlI:{}", path)),
+      m_dData(fmt::format("NTPIDCtrlD:{}", path)),
+      m_setpointData(fmt::format("NTPIDCtrlStpt:{}", path)),
+      m_nameValue(wpi::rsplit(path, '/').second) {
   m_nt.AddListener(m_name);
   m_nt.AddListener(m_controllable);
   m_nt.AddListener(m_p);
diff --git a/glass/src/libnt/native/cpp/NTSpeedController.cpp b/glass/src/libnt/native/cpp/NTSpeedController.cpp
index 8dd9142cc6..a4fc1cab2f 100644
--- a/glass/src/libnt/native/cpp/NTSpeedController.cpp
+++ b/glass/src/libnt/native/cpp/NTSpeedController.cpp
@@ -4,19 +4,22 @@
 
 #include "glass/networktables/NTSpeedController.h"
 
+#include <fmt/format.h>
+#include <wpi/StringExtras.h>
+
 using namespace glass;
 
-NTSpeedControllerModel::NTSpeedControllerModel(wpi::StringRef path)
+NTSpeedControllerModel::NTSpeedControllerModel(std::string_view path)
     : NTSpeedControllerModel(nt::GetDefaultInstance(), path) {}
 
 NTSpeedControllerModel::NTSpeedControllerModel(NT_Inst instance,
-                                               wpi::StringRef path)
+                                               std::string_view path)
     : m_nt(instance),
-      m_value(m_nt.GetEntry(path + "/Value")),
-      m_name(m_nt.GetEntry(path + "/.name")),
-      m_controllable(m_nt.GetEntry(path + "/.controllable")),
-      m_valueData("NT_SpdCtrl:" + path),
-      m_nameValue(path.rsplit('/').second) {
+      m_value(m_nt.GetEntry(fmt::format("{}/Value", path))),
+      m_name(m_nt.GetEntry(fmt::format("{}/.name", path))),
+      m_controllable(m_nt.GetEntry(fmt::format("{}/.controllable"))),
+      m_valueData(fmt::format("NT_SpdCtrl:{}", path)),
+      m_nameValue(wpi::rsplit(path, '/').second) {
   m_nt.AddListener(m_value);
   m_nt.AddListener(m_name);
   m_nt.AddListener(m_controllable);
diff --git a/glass/src/libnt/native/cpp/NTStringChooser.cpp b/glass/src/libnt/native/cpp/NTStringChooser.cpp
index e1c8d3bf18..47eb787ea5 100644
--- a/glass/src/libnt/native/cpp/NTStringChooser.cpp
+++ b/glass/src/libnt/native/cpp/NTStringChooser.cpp
@@ -4,32 +4,34 @@
 
 #include "glass/networktables/NTStringChooser.h"
 
+#include <fmt/format.h>
+
 using namespace glass;
 
-NTStringChooserModel::NTStringChooserModel(wpi::StringRef path)
+NTStringChooserModel::NTStringChooserModel(std::string_view path)
     : NTStringChooserModel{nt::GetDefaultInstance(), path} {}
 
-NTStringChooserModel::NTStringChooserModel(NT_Inst inst, wpi::StringRef path)
+NTStringChooserModel::NTStringChooserModel(NT_Inst inst, std::string_view path)
     : m_nt{inst},
-      m_default{m_nt.GetEntry(path + "/default")},
-      m_selected{m_nt.GetEntry(path + "/selected")},
-      m_active{m_nt.GetEntry(path + "/active")},
-      m_options{m_nt.GetEntry(path + "/options")} {
+      m_default{m_nt.GetEntry(fmt::format("{}/default", path))},
+      m_selected{m_nt.GetEntry(fmt::format("{}/selected", path))},
+      m_active{m_nt.GetEntry(fmt::format("{}/active", path))},
+      m_options{m_nt.GetEntry(fmt::format("{}/options", path))} {
   m_nt.AddListener(m_default);
   m_nt.AddListener(m_selected);
   m_nt.AddListener(m_active);
   m_nt.AddListener(m_options);
 }
 
-void NTStringChooserModel::SetDefault(wpi::StringRef val) {
+void NTStringChooserModel::SetDefault(std::string_view val) {
   nt::SetEntryValue(m_default, nt::Value::MakeString(val));
 }
 
-void NTStringChooserModel::SetSelected(wpi::StringRef val) {
+void NTStringChooserModel::SetSelected(std::string_view val) {
   nt::SetEntryValue(m_selected, nt::Value::MakeString(val));
 }
 
-void NTStringChooserModel::SetActive(wpi::StringRef val) {
+void NTStringChooserModel::SetActive(std::string_view val) {
   nt::SetEntryValue(m_active, nt::Value::MakeString(val));
 }
 
diff --git a/glass/src/libnt/native/cpp/NTSubsystem.cpp b/glass/src/libnt/native/cpp/NTSubsystem.cpp
index e7976ec958..b2bdf8c837 100644
--- a/glass/src/libnt/native/cpp/NTSubsystem.cpp
+++ b/glass/src/libnt/native/cpp/NTSubsystem.cpp
@@ -4,16 +4,18 @@
 
 #include "glass/networktables/NTSubsystem.h"
 
+#include <fmt/format.h>
+
 using namespace glass;
 
-NTSubsystemModel::NTSubsystemModel(wpi::StringRef path)
+NTSubsystemModel::NTSubsystemModel(std::string_view path)
     : NTSubsystemModel(nt::GetDefaultInstance(), path) {}
 
-NTSubsystemModel::NTSubsystemModel(NT_Inst instance, wpi::StringRef path)
+NTSubsystemModel::NTSubsystemModel(NT_Inst instance, std::string_view path)
     : m_nt(instance),
-      m_name(m_nt.GetEntry(path + "/.name")),
-      m_defaultCommand(m_nt.GetEntry(path + "/.default")),
-      m_currentCommand(m_nt.GetEntry(path + "/.command")) {
+      m_name(m_nt.GetEntry(fmt::format("{}/.name", path))),
+      m_defaultCommand(m_nt.GetEntry(fmt::format("{}/.default", path))),
+      m_currentCommand(m_nt.GetEntry(fmt::format("{}/.command", path))) {
   m_nt.AddListener(m_name);
   m_nt.AddListener(m_defaultCommand);
   m_nt.AddListener(m_currentCommand);
diff --git a/glass/src/libnt/native/cpp/NetworkTables.cpp b/glass/src/libnt/native/cpp/NetworkTables.cpp
index cea8be538f..0e0955d3ce 100644
--- a/glass/src/libnt/native/cpp/NetworkTables.cpp
+++ b/glass/src/libnt/native/cpp/NetworkTables.cpp
@@ -11,14 +11,15 @@
 #include <cstring>
 #include <initializer_list>
 #include <memory>
+#include <string_view>
 #include <vector>
 
+#include <fmt/format.h>
 #include <imgui.h>
 #include <ntcore_cpp.h>
 #include <wpi/ArrayRef.h>
-#include <wpi/Format.h>
 #include <wpi/SmallString.h>
-#include <wpi/StringRef.h>
+#include <wpi/StringExtras.h>
 #include <wpi/raw_ostream.h>
 
 #include "glass/Context.h"
@@ -47,19 +48,7 @@ static std::string BooleanArrayToString(wpi::ArrayRef<int> in) {
 }
 
 static std::string DoubleArrayToString(wpi::ArrayRef<double> in) {
-  std::string rv;
-  wpi::raw_string_ostream os{rv};
-  os << '[';
-  bool first = true;
-  for (auto v : in) {
-    if (!first) {
-      os << ',';
-    }
-    first = false;
-    os << wpi::format("%.6f", v);
-  }
-  os << ']';
-  return rv;
+  return fmt::format("[{:.6f}]", fmt::join(in, ","));
 }
 
 static std::string StringArrayToString(wpi::ArrayRef<std::string> in) {
@@ -107,14 +96,14 @@ void NetworkTablesModel::Entry::UpdateValue() {
   switch (value->type()) {
     case NT_BOOLEAN:
       if (!source) {
-        source = std::make_unique<DataSource>(wpi::Twine{"NT:"} + name);
+        source = std::make_unique<DataSource>(fmt::format("NT:{}", name));
       }
       source->SetValue(value->GetBoolean() ? 1 : 0);
       source->SetDigital(true);
       break;
     case NT_DOUBLE:
       if (!source) {
-        source = std::make_unique<DataSource>(wpi::Twine{"NT:"} + name);
+        source = std::make_unique<DataSource>(fmt::format("NT:{}", name));
       }
       source->SetValue(value->GetDouble());
       source->SetDigital(false);
@@ -185,10 +174,10 @@ void NetworkTablesModel::Update() {
 
   // rebuild tree
   m_root.clear();
-  wpi::SmallVector<wpi::StringRef, 16> parts;
+  wpi::SmallVector<std::string_view, 16> parts;
   for (auto& entry : m_sortedEntries) {
     parts.clear();
-    wpi::StringRef{entry->name}.split(parts, '/', -1, false);
+    wpi::split(entry->name, parts, '/', -1, false);
 
     // ignore a raw "/" key
     if (parts.empty()) {
@@ -206,8 +195,8 @@ void NetworkTablesModel::Update() {
         // path is from the beginning of the string to the end of the current
         // part; this works because part is a reference to the internals of
         // entry->name
-        nodes->back().path.assign(entry->name.data(),
-                                  part.end() - entry->name.data());
+        nodes->back().path.assign(
+            entry->name.data(), part.data() + part.size() - entry->name.data());
         it = nodes->end() - 1;
       }
       nodes = &it->children;
@@ -229,33 +218,33 @@ bool NetworkTablesModel::Exists() {
   return nt::IsConnected(m_inst);
 }
 
-static std::shared_ptr<nt::Value> StringToBooleanArray(wpi::StringRef in) {
-  in = in.trim();
+static std::shared_ptr<nt::Value> StringToBooleanArray(std::string_view in) {
+  in = wpi::trim(in);
   if (in.empty()) {
     return nt::NetworkTableValue::MakeBooleanArray(
         std::initializer_list<bool>{});
   }
   if (in.front() == '[') {
-    in = in.drop_front();
+    in.remove_prefix(1);
   }
   if (in.back() == ']') {
-    in = in.drop_back();
+    in.remove_suffix(1);
   }
-  in = in.trim();
+  in = wpi::trim(in);
 
-  wpi::SmallVector<wpi::StringRef, 16> inSplit;
+  wpi::SmallVector<std::string_view, 16> inSplit;
   wpi::SmallVector<int, 16> out;
 
-  in.split(inSplit, ',', -1, false);
+  wpi::split(in, inSplit, ',', -1, false);
   for (auto val : inSplit) {
-    val = val.trim();
-    if (val.equals_lower("true")) {
+    val = wpi::trim(val);
+    if (wpi::equals_lower(val, "true")) {
       out.emplace_back(1);
-    } else if (val.equals_lower("false")) {
+    } else if (wpi::equals_lower(val, "false")) {
       out.emplace_back(0);
     } else {
-      wpi::errs() << "GUI: NetworkTables: Could not understand value '" << val
-                  << "'\n";
+      fmt::print(stderr,
+                 "GUI: NetworkTables: Could not understand value '{}'\n", val);
       return nullptr;
     }
   }
@@ -263,33 +252,30 @@ static std::shared_ptr<nt::Value> StringToBooleanArray(wpi::StringRef in) {
   return nt::NetworkTableValue::MakeBooleanArray(out);
 }
 
-static std::shared_ptr<nt::Value> StringToDoubleArray(wpi::StringRef in) {
-  in = in.trim();
+static std::shared_ptr<nt::Value> StringToDoubleArray(std::string_view in) {
+  in = wpi::trim(in);
   if (in.empty()) {
     return nt::NetworkTableValue::MakeDoubleArray(
         std::initializer_list<double>{});
   }
   if (in.front() == '[') {
-    in = in.drop_front();
+    in.remove_prefix(1);
   }
   if (in.back() == ']') {
-    in = in.drop_back();
+    in.remove_suffix(1);
   }
-  in = in.trim();
+  in = wpi::trim(in);
 
-  wpi::SmallVector<wpi::StringRef, 16> inSplit;
+  wpi::SmallVector<std::string_view, 16> inSplit;
   wpi::SmallVector<double, 16> out;
 
-  in.split(inSplit, ',', -1, false);
+  wpi::split(in, inSplit, ',', -1, false);
   for (auto val : inSplit) {
-    val = val.trim();
-    wpi::SmallString<32> valStr = val;
-    double d;
-    if (std::sscanf(valStr.c_str(), "%lf", &d) == 1) {
-      out.emplace_back(d);
+    if (auto num = wpi::parse_float<double>(wpi::trim(val))) {
+      out.emplace_back(num.value());
     } else {
-      wpi::errs() << "GUI: NetworkTables: Could not understand value '" << val
-                  << "'\n";
+      fmt::print(stderr,
+                 "GUI: NetworkTables: Could not understand value '{}'\n", val);
       return nullptr;
     }
   }
@@ -307,8 +293,8 @@ static int fromxdigit(char ch) {
   }
 }
 
-static wpi::StringRef UnescapeString(wpi::StringRef source,
-                                     wpi::SmallVectorImpl<char>& buf) {
+static std::string_view UnescapeString(std::string_view source,
+                                       wpi::SmallVectorImpl<char>& buf) {
   assert(source.size() >= 2 && source.front() == '"' && source.back() == '"');
   buf.clear();
   buf.reserve(source.size() - 2);
@@ -342,36 +328,36 @@ static wpi::StringRef UnescapeString(wpi::StringRef source,
         break;
     }
   }
-  return wpi::StringRef{buf.data(), buf.size()};
+  return {buf.data(), buf.size()};
 }
 
-static std::shared_ptr<nt::Value> StringToStringArray(wpi::StringRef in) {
-  in = in.trim();
+static std::shared_ptr<nt::Value> StringToStringArray(std::string_view in) {
+  in = wpi::trim(in);
   if (in.empty()) {
     return nt::NetworkTableValue::MakeStringArray(
         std::initializer_list<std::string>{});
   }
   if (in.front() == '[') {
-    in = in.drop_front();
+    in.remove_prefix(1);
   }
   if (in.back() == ']') {
-    in = in.drop_back();
+    in.remove_suffix(1);
   }
-  in = in.trim();
+  in = wpi::trim(in);
 
-  wpi::SmallVector<wpi::StringRef, 16> inSplit;
+  wpi::SmallVector<std::string_view, 16> inSplit;
   std::vector<std::string> out;
   wpi::SmallString<32> buf;
 
-  in.split(inSplit, ',', -1, false);
+  wpi::split(in, inSplit, ',', -1, false);
   for (auto val : inSplit) {
-    val = val.trim();
+    val = wpi::trim(val);
     if (val.empty()) {
       continue;
     }
     if (val.front() != '"' || val.back() != '"') {
-      wpi::errs() << "GUI: NetworkTables: Could not understand value '" << val
-                  << "'\n";
+      fmt::print(stderr,
+                 "GUI: NetworkTables: Could not understand value '{}'\n", val);
       return nullptr;
     }
     out.emplace_back(UnescapeString(val, buf));
@@ -421,7 +407,7 @@ static void EmitEntryValueReadonly(NetworkTablesModel::Entry& entry) {
 
 static constexpr size_t kTextBufferSize = 4096;
 
-static char* GetTextBuffer(wpi::StringRef in) {
+static char* GetTextBuffer(std::string_view in) {
   static char textBuffer[kTextBufferSize];
   size_t len = (std::min)(in.size(), kTextBufferSize - 1);
   std::memcpy(textBuffer, in.data(), len);
@@ -524,7 +510,7 @@ static void EmitParentContextMenu(const std::string& path,
       if (path == "/") {
         fullNewPath = path + nameBuffer;
       } else {
-        fullNewPath = (path + wpi::Twine('/') + nameBuffer).str();
+        fullNewPath = fmt::format("{}/{}", path, nameBuffer);
       }
 
       ImGui::Text("Adding: %s", fullNewPath.c_str());
diff --git a/glass/src/libnt/native/cpp/NetworkTablesProvider.cpp b/glass/src/libnt/native/cpp/NetworkTablesProvider.cpp
index 7431380752..8d991cb78d 100644
--- a/glass/src/libnt/native/cpp/NetworkTablesProvider.cpp
+++ b/glass/src/libnt/native/cpp/NetworkTablesProvider.cpp
@@ -6,18 +6,22 @@
 
 #include <algorithm>
 
+#include <fmt/format.h>
 #include <ntcore_cpp.h>
 #include <wpi/SmallString.h>
+#include <wpi/StringExtras.h>
 #include <wpigui.h>
 
 using namespace glass;
 
-NetworkTablesProvider::NetworkTablesProvider(const wpi::Twine& iniName)
+NetworkTablesProvider::NetworkTablesProvider(std::string_view iniName)
     : NetworkTablesProvider{iniName, nt::GetDefaultInstance()} {}
 
-NetworkTablesProvider::NetworkTablesProvider(const wpi::Twine& iniName,
+NetworkTablesProvider::NetworkTablesProvider(std::string_view iniName,
                                              NT_Inst inst)
-    : Provider{iniName + "Window"}, m_nt{inst}, m_typeCache{iniName} {
+    : Provider{fmt::format("{}Window", iniName)},
+      m_nt{inst},
+      m_typeCache{iniName} {
   m_nt.AddListener("", NT_NOTIFY_LOCAL | NT_NOTIFY_NEW | NT_NOTIFY_DELETE |
                            NT_NOTIFY_IMMEDIATE);
 }
@@ -28,11 +32,11 @@ void NetworkTablesProvider::GlobalInit() {
 }
 
 void NetworkTablesProvider::DisplayMenu() {
-  wpi::SmallVector<wpi::StringRef, 6> path;
+  wpi::SmallVector<std::string_view, 6> path;
   wpi::SmallString<64> name;
   for (auto&& entry : m_viewEntries) {
     path.clear();
-    wpi::StringRef{entry->name}.split(path, '/', -1, false);
+    wpi::split(entry->name, path, '/', -1, false);
 
     bool fullDepth = true;
     int depth = 0;
@@ -69,12 +73,12 @@ void NetworkTablesProvider::Update() {
   // add/remove entries from NT changes
   for (auto&& event : m_nt.PollListener()) {
     // look for .type fields
-    wpi::StringRef eventName{event.name};
-    if (!eventName.endswith("/.type") || !event.value ||
+    std::string_view eventName{event.name};
+    if (!wpi::ends_with(eventName, "/.type") || !event.value ||
         !event.value->IsString()) {
       continue;
     }
-    auto tableName = eventName.drop_back(6);
+    auto tableName = wpi::drop_back(eventName, 6);
 
     // only handle ones where we have a builder
     auto builderIt = m_typeMap.find(event.value->GetString());
@@ -117,14 +121,15 @@ void NetworkTablesProvider::Update() {
     }
 
     auto entry = GetOrCreateView(
-        builderIt->second, nt::GetEntry(m_nt.GetInstance(), id + "/.type"), id);
+        builderIt->second,
+        nt::GetEntry(m_nt.GetInstance(), fmt::format("{}/.type", id)), id);
     if (entry) {
       Show(entry, window.get());
     }
   }
 }
 
-void NetworkTablesProvider::Register(wpi::StringRef typeName,
+void NetworkTablesProvider::Register(std::string_view typeName,
                                      CreateModelFunc createModel,
                                      CreateViewFunc createView) {
   m_typeMap[typeName] = Builder{std::move(createModel), std::move(createView)};
@@ -153,9 +158,9 @@ void NetworkTablesProvider::Show(ViewEntry* entry, Window* window) {
   if (!window) {
     return;
   }
-  if (wpi::StringRef{entry->name}.startswith("/SmartDashboard/")) {
-    window->SetDefaultName(wpi::StringRef{entry->name}.drop_front(16) +
-                           " (SmartDashboard)");
+  if (wpi::starts_with(entry->name, "/SmartDashboard/")) {
+    window->SetDefaultName(
+        fmt::format("{} (SmartDashboard)", wpi::drop_front(entry->name, 16)));
   }
   entry->window = window;
 
@@ -171,7 +176,7 @@ void NetworkTablesProvider::Show(ViewEntry* entry, Window* window) {
 }
 
 NetworkTablesProvider::ViewEntry* NetworkTablesProvider::GetOrCreateView(
-    const Builder& builder, NT_Entry typeEntry, wpi::StringRef name) {
+    const Builder& builder, NT_Entry typeEntry, std::string_view name) {
   // get view entry if it already exists
   auto viewIt = FindViewEntry(name);
   if (viewIt != m_viewEntries.end() && (*viewIt)->name == name) {
diff --git a/glass/src/libnt/native/cpp/NetworkTablesSettings.cpp b/glass/src/libnt/native/cpp/NetworkTablesSettings.cpp
index 2a603b6eae..28f4de4bcd 100644
--- a/glass/src/libnt/native/cpp/NetworkTablesSettings.cpp
+++ b/glass/src/libnt/native/cpp/NetworkTablesSettings.cpp
@@ -4,14 +4,15 @@
 
 #include "glass/networktables/NetworkTablesSettings.h"
 
+#include <optional>
+#include <string_view>
 #include <utility>
 
 #include <imgui.h>
 #include <imgui_stdlib.h>
 #include <ntcore_cpp.h>
 #include <wpi/SmallVector.h>
-#include <wpi/StringRef.h>
-#include <wpi/raw_ostream.h>
+#include <wpi/StringExtras.h>
 
 #include "glass/Context.h"
 
@@ -55,14 +56,15 @@ void NetworkTablesSettings::Thread::Main() {
     } while (mode != m_mode || dsClient != m_dsClient);
 
     if (m_mode == 1) {
-      wpi::StringRef serverTeam{m_serverTeam};
-      unsigned int team;
-      if (!serverTeam.contains('.') && !serverTeam.getAsInteger(10, team)) {
-        nt::StartClientTeam(m_inst, team, NT_DEFAULT_PORT);
+      std::string_view serverTeam{m_serverTeam};
+      std::optional<unsigned int> team;
+      if (!wpi::contains(serverTeam, '.') &&
+          (team = wpi::parse_integer<unsigned int>(serverTeam, 10))) {
+        nt::StartClientTeam(m_inst, team.value(), NT_DEFAULT_PORT);
       } else {
-        wpi::SmallVector<wpi::StringRef, 4> serverNames;
-        wpi::SmallVector<std::pair<wpi::StringRef, unsigned int>, 4> servers;
-        serverTeam.split(serverNames, ',', -1, false);
+        wpi::SmallVector<std::string_view, 4> serverNames;
+        wpi::SmallVector<std::pair<std::string_view, unsigned int>, 4> servers;
+        wpi::split(serverTeam, serverNames, ',', -1, false);
         for (auto&& serverName : serverNames) {
           servers.emplace_back(serverName, NT_DEFAULT_PORT);
         }
diff --git a/glass/src/libnt/native/include/glass/networktables/NTCommandScheduler.h b/glass/src/libnt/native/include/glass/networktables/NTCommandScheduler.h
index a9aad0f2f5..54dc778841 100644
--- a/glass/src/libnt/native/include/glass/networktables/NTCommandScheduler.h
+++ b/glass/src/libnt/native/include/glass/networktables/NTCommandScheduler.h
@@ -5,10 +5,10 @@
 #pragma once
 
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <ntcore_cpp.h>
-#include <wpi/StringRef.h>
 
 #include "glass/DataSource.h"
 #include "glass/networktables/NetworkTablesHelper.h"
@@ -19,8 +19,8 @@ class NTCommandSchedulerModel : public CommandSchedulerModel {
  public:
   static constexpr const char* kType = "Scheduler";
 
-  explicit NTCommandSchedulerModel(wpi::StringRef path);
-  NTCommandSchedulerModel(NT_Inst instance, wpi::StringRef path);
+  explicit NTCommandSchedulerModel(std::string_view path);
+  NTCommandSchedulerModel(NT_Inst instance, std::string_view path);
 
   const char* GetName() const override { return m_nameValue.c_str(); }
   const std::vector<std::string>& GetCurrentCommands() override {
diff --git a/glass/src/libnt/native/include/glass/networktables/NTCommandSelector.h b/glass/src/libnt/native/include/glass/networktables/NTCommandSelector.h
index 002a1eb34a..c936665915 100644
--- a/glass/src/libnt/native/include/glass/networktables/NTCommandSelector.h
+++ b/glass/src/libnt/native/include/glass/networktables/NTCommandSelector.h
@@ -5,9 +5,9 @@
 #pragma once
 
 #include <string>
+#include <string_view>
 
 #include <ntcore_cpp.h>
-#include <wpi/StringRef.h>
 
 #include "glass/DataSource.h"
 #include "glass/networktables/NetworkTablesHelper.h"
@@ -18,8 +18,8 @@ class NTCommandSelectorModel : public CommandSelectorModel {
  public:
   static constexpr const char* kType = "Command";
 
-  explicit NTCommandSelectorModel(wpi::StringRef path);
-  NTCommandSelectorModel(NT_Inst instance, wpi::StringRef path);
+  explicit NTCommandSelectorModel(std::string_view path);
+  NTCommandSelectorModel(NT_Inst instance, std::string_view path);
 
   const char* GetName() const override { return m_nameValue.c_str(); }
   DataSource* GetRunningData() override { return &m_runningData; }
diff --git a/glass/src/libnt/native/include/glass/networktables/NTDifferentialDrive.h b/glass/src/libnt/native/include/glass/networktables/NTDifferentialDrive.h
index b6e741b636..3dcf72106d 100644
--- a/glass/src/libnt/native/include/glass/networktables/NTDifferentialDrive.h
+++ b/glass/src/libnt/native/include/glass/networktables/NTDifferentialDrive.h
@@ -5,11 +5,11 @@
 #pragma once
 
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <ntcore_cpp.h>
 #include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
 
 #include "glass/DataSource.h"
 #include "glass/networktables/NetworkTablesHelper.h"
@@ -20,8 +20,8 @@ class NTDifferentialDriveModel : public DriveModel {
  public:
   static constexpr const char* kType = "DifferentialDrive";
 
-  explicit NTDifferentialDriveModel(wpi::StringRef path);
-  NTDifferentialDriveModel(NT_Inst instance, wpi::StringRef path);
+  explicit NTDifferentialDriveModel(std::string_view path);
+  NTDifferentialDriveModel(NT_Inst instance, std::string_view path);
 
   const char* GetName() const override { return m_nameValue.c_str(); }
   const std::vector<DriveModel::WheelInfo>& GetWheels() const override {
diff --git a/glass/src/libnt/native/include/glass/networktables/NTDigitalInput.h b/glass/src/libnt/native/include/glass/networktables/NTDigitalInput.h
index f3b4155a87..cd3dfebc1c 100644
--- a/glass/src/libnt/native/include/glass/networktables/NTDigitalInput.h
+++ b/glass/src/libnt/native/include/glass/networktables/NTDigitalInput.h
@@ -5,9 +5,9 @@
 #pragma once
 
 #include <string>
+#include <string_view>
 
 #include <ntcore_cpp.h>
-#include <wpi/StringRef.h>
 
 #include "glass/DataSource.h"
 #include "glass/hardware/DIO.h"
@@ -20,8 +20,8 @@ class NTDigitalInputModel : public DIOModel {
   static constexpr const char* kType = "Digital Input";
 
   // path is to the table containing ".type", excluding the trailing /
-  explicit NTDigitalInputModel(wpi::StringRef path);
-  NTDigitalInputModel(NT_Inst inst, wpi::StringRef path);
+  explicit NTDigitalInputModel(std::string_view path);
+  NTDigitalInputModel(NT_Inst inst, std::string_view path);
 
   const char* GetName() const override { return m_nameValue.c_str(); }
 
diff --git a/glass/src/libnt/native/include/glass/networktables/NTDigitalOutput.h b/glass/src/libnt/native/include/glass/networktables/NTDigitalOutput.h
index 0f1604d880..8ed1ee7207 100644
--- a/glass/src/libnt/native/include/glass/networktables/NTDigitalOutput.h
+++ b/glass/src/libnt/native/include/glass/networktables/NTDigitalOutput.h
@@ -5,9 +5,9 @@
 #pragma once
 
 #include <string>
+#include <string_view>
 
 #include <ntcore_cpp.h>
-#include <wpi/StringRef.h>
 
 #include "glass/DataSource.h"
 #include "glass/hardware/DIO.h"
@@ -20,8 +20,8 @@ class NTDigitalOutputModel : public DIOModel {
   static constexpr const char* kType = "Digital Output";
 
   // path is to the table containing ".type", excluding the trailing /
-  explicit NTDigitalOutputModel(wpi::StringRef path);
-  NTDigitalOutputModel(NT_Inst inst, wpi::StringRef path);
+  explicit NTDigitalOutputModel(std::string_view path);
+  NTDigitalOutputModel(NT_Inst inst, std::string_view path);
 
   const char* GetName() const override { return m_nameValue.c_str(); }
 
diff --git a/glass/src/libnt/native/include/glass/networktables/NTFMS.h b/glass/src/libnt/native/include/glass/networktables/NTFMS.h
index 1aa0193eca..b19a9f02da 100644
--- a/glass/src/libnt/native/include/glass/networktables/NTFMS.h
+++ b/glass/src/libnt/native/include/glass/networktables/NTFMS.h
@@ -4,8 +4,9 @@
 
 #pragma once
 
+#include <string_view>
+
 #include <ntcore_cpp.h>
-#include <wpi/StringRef.h>
 
 #include "glass/DataSource.h"
 #include "glass/networktables/NetworkTablesHelper.h"
@@ -18,8 +19,8 @@ class NTFMSModel : public FMSModel {
   static constexpr const char* kType = "FMSInfo";
 
   // path is to the table containing ".type", excluding the trailing /
-  explicit NTFMSModel(wpi::StringRef path);
-  NTFMSModel(NT_Inst inst, wpi::StringRef path);
+  explicit NTFMSModel(std::string_view path);
+  NTFMSModel(NT_Inst inst, std::string_view path);
 
   DataSource* GetFmsAttachedData() override { return &m_fmsAttached; }
   DataSource* GetDsAttachedData() override { return &m_dsAttached; }
@@ -32,7 +33,7 @@ class NTFMSModel : public FMSModel {
   DataSource* GetEnabledData() override { return &m_enabled; }
   DataSource* GetTestData() override { return &m_test; }
   DataSource* GetAutonomousData() override { return &m_autonomous; }
-  wpi::StringRef GetGameSpecificMessage(
+  std::string_view GetGameSpecificMessage(
       wpi::SmallVectorImpl<char>& buf) override;
 
   // NT is read-only (it's continually set by robot code)
diff --git a/glass/src/libnt/native/include/glass/networktables/NTField2D.h b/glass/src/libnt/native/include/glass/networktables/NTField2D.h
index c44b2a13a9..f966e0f01d 100644
--- a/glass/src/libnt/native/include/glass/networktables/NTField2D.h
+++ b/glass/src/libnt/native/include/glass/networktables/NTField2D.h
@@ -6,11 +6,11 @@
 
 #include <memory>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
 #include <ntcore_cpp.h>
-#include <wpi/StringRef.h>
 
 #include "glass/networktables/NetworkTablesHelper.h"
 #include "glass/other/Field2D.h"
@@ -22,8 +22,8 @@ class NTField2DModel : public Field2DModel {
   static constexpr const char* kType = "Field2d";
 
   // path is to the table containing ".type", excluding the trailing /
-  explicit NTField2DModel(wpi::StringRef path);
-  NTField2DModel(NT_Inst inst, wpi::StringRef path);
+  explicit NTField2DModel(std::string_view path);
+  NTField2DModel(NT_Inst inst, std::string_view path);
   ~NTField2DModel() override;
 
   const char* GetPath() const { return m_path.c_str(); }
@@ -33,10 +33,10 @@ class NTField2DModel : public Field2DModel {
   bool Exists() override;
   bool IsReadOnly() override;
 
-  FieldObjectModel* AddFieldObject(const wpi::Twine& name) override;
-  void RemoveFieldObject(const wpi::Twine& name) override;
+  FieldObjectModel* AddFieldObject(std::string_view name) override;
+  void RemoveFieldObject(std::string_view name) override;
   void ForEachFieldObject(
-      wpi::function_ref<void(FieldObjectModel& model, wpi::StringRef name)>
+      wpi::function_ref<void(FieldObjectModel& model, std::string_view name)>
           func) override;
 
  private:
@@ -49,7 +49,7 @@ class NTField2DModel : public Field2DModel {
   using Objects = std::vector<std::unique_ptr<ObjectModel>>;
   Objects m_objects;
 
-  std::pair<Objects::iterator, bool> Find(wpi::StringRef fullName);
+  std::pair<Objects::iterator, bool> Find(std::string_view fullName);
 };
 
 }  // namespace glass
diff --git a/glass/src/libnt/native/include/glass/networktables/NTGyro.h b/glass/src/libnt/native/include/glass/networktables/NTGyro.h
index 48d6fffef2..db303a569a 100644
--- a/glass/src/libnt/native/include/glass/networktables/NTGyro.h
+++ b/glass/src/libnt/native/include/glass/networktables/NTGyro.h
@@ -3,10 +3,11 @@
 // the WPILib BSD license file in the root directory of this project.
 
 #pragma once
+
 #include <string>
+#include <string_view>
 
 #include <ntcore_cpp.h>
-#include <wpi/StringRef.h>
 
 #include "glass/DataSource.h"
 #include "glass/hardware/Gyro.h"
@@ -17,8 +18,8 @@ class NTGyroModel : public GyroModel {
  public:
   static constexpr const char* kType = "Gyro";
 
-  explicit NTGyroModel(wpi::StringRef path);
-  NTGyroModel(NT_Inst instance, wpi::StringRef path);
+  explicit NTGyroModel(std::string_view path);
+  NTGyroModel(NT_Inst instance, std::string_view path);
 
   const char* GetName() const override { return m_nameValue.c_str(); }
   const char* GetSimDevice() const override { return nullptr; }
diff --git a/glass/src/libnt/native/include/glass/networktables/NTMecanumDrive.h b/glass/src/libnt/native/include/glass/networktables/NTMecanumDrive.h
index f002a47b2c..3d4718a207 100644
--- a/glass/src/libnt/native/include/glass/networktables/NTMecanumDrive.h
+++ b/glass/src/libnt/native/include/glass/networktables/NTMecanumDrive.h
@@ -5,11 +5,11 @@
 #pragma once
 
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <ntcore_cpp.h>
 #include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
 
 #include "glass/DataSource.h"
 #include "glass/networktables/NetworkTablesHelper.h"
@@ -20,8 +20,8 @@ class NTMecanumDriveModel : public DriveModel {
  public:
   static constexpr const char* kType = "MecanumDrive";
 
-  explicit NTMecanumDriveModel(wpi::StringRef path);
-  NTMecanumDriveModel(NT_Inst instance, wpi::StringRef path);
+  explicit NTMecanumDriveModel(std::string_view path);
+  NTMecanumDriveModel(NT_Inst instance, std::string_view path);
 
   const char* GetName() const override { return m_nameValue.c_str(); }
   const std::vector<DriveModel::WheelInfo>& GetWheels() const override {
diff --git a/glass/src/libnt/native/include/glass/networktables/NTMechanism2D.h b/glass/src/libnt/native/include/glass/networktables/NTMechanism2D.h
index 5157b08345..81f7df1cb4 100644
--- a/glass/src/libnt/native/include/glass/networktables/NTMechanism2D.h
+++ b/glass/src/libnt/native/include/glass/networktables/NTMechanism2D.h
@@ -6,12 +6,12 @@
 
 #include <memory>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
 #include <frc/geometry/Translation2d.h>
 #include <ntcore_cpp.h>
-#include <wpi/StringRef.h>
 
 #include "glass/networktables/NetworkTablesHelper.h"
 #include "glass/other/Mechanism2D.h"
@@ -23,8 +23,8 @@ class NTMechanism2DModel : public Mechanism2DModel {
   static constexpr const char* kType = "Mechanism2d";
 
   // path is to the table containing ".type", excluding the trailing /
-  explicit NTMechanism2DModel(wpi::StringRef path);
-  NTMechanism2DModel(NT_Inst inst, wpi::StringRef path);
+  explicit NTMechanism2DModel(std::string_view path);
+  NTMechanism2DModel(NT_Inst inst, std::string_view path);
   ~NTMechanism2DModel() override;
 
   const char* GetPath() const { return m_path.c_str(); }
diff --git a/glass/src/libnt/native/include/glass/networktables/NTPIDController.h b/glass/src/libnt/native/include/glass/networktables/NTPIDController.h
index 930ef54dab..b975641f55 100644
--- a/glass/src/libnt/native/include/glass/networktables/NTPIDController.h
+++ b/glass/src/libnt/native/include/glass/networktables/NTPIDController.h
@@ -5,9 +5,9 @@
 #pragma once
 
 #include <string>
+#include <string_view>
 
 #include <ntcore_cpp.h>
-#include <wpi/StringRef.h>
 
 #include "glass/DataSource.h"
 #include "glass/networktables/NetworkTablesHelper.h"
@@ -18,8 +18,8 @@ class NTPIDControllerModel : public PIDControllerModel {
  public:
   static constexpr const char* kType = "PIDController";
 
-  explicit NTPIDControllerModel(wpi::StringRef path);
-  NTPIDControllerModel(NT_Inst instance, wpi::StringRef path);
+  explicit NTPIDControllerModel(std::string_view path);
+  NTPIDControllerModel(NT_Inst instance, std::string_view path);
 
   const char* GetName() const override { return m_nameValue.c_str(); }
 
diff --git a/glass/src/libnt/native/include/glass/networktables/NTSpeedController.h b/glass/src/libnt/native/include/glass/networktables/NTSpeedController.h
index 1a30d9ffce..756d94744e 100644
--- a/glass/src/libnt/native/include/glass/networktables/NTSpeedController.h
+++ b/glass/src/libnt/native/include/glass/networktables/NTSpeedController.h
@@ -5,9 +5,9 @@
 #pragma once
 
 #include <string>
+#include <string_view>
 
 #include <ntcore_cpp.h>
-#include <wpi/StringRef.h>
 
 #include "glass/DataSource.h"
 #include "glass/hardware/SpeedController.h"
@@ -18,8 +18,8 @@ class NTSpeedControllerModel : public SpeedControllerModel {
  public:
   static constexpr const char* kType = "Speed Controller";
 
-  explicit NTSpeedControllerModel(wpi::StringRef path);
-  NTSpeedControllerModel(NT_Inst instance, wpi::StringRef path);
+  explicit NTSpeedControllerModel(std::string_view path);
+  NTSpeedControllerModel(NT_Inst instance, std::string_view path);
 
   const char* GetName() const override { return m_nameValue.c_str(); }
   const char* GetSimDevice() const override { return nullptr; }
diff --git a/glass/src/libnt/native/include/glass/networktables/NTStringChooser.h b/glass/src/libnt/native/include/glass/networktables/NTStringChooser.h
index 2262708647..fac9f7c53a 100644
--- a/glass/src/libnt/native/include/glass/networktables/NTStringChooser.h
+++ b/glass/src/libnt/native/include/glass/networktables/NTStringChooser.h
@@ -19,8 +19,8 @@ class NTStringChooserModel : public StringChooserModel {
   static constexpr const char* kType = "String Chooser";
 
   // path is to the table containing ".type", excluding the trailing /
-  explicit NTStringChooserModel(wpi::StringRef path);
-  NTStringChooserModel(NT_Inst inst, wpi::StringRef path);
+  explicit NTStringChooserModel(std::string_view path);
+  NTStringChooserModel(NT_Inst inst, std::string_view path);
 
   const std::string& GetDefault() override { return m_defaultValue; }
   const std::string& GetSelected() override { return m_selectedValue; }
@@ -29,9 +29,9 @@ class NTStringChooserModel : public StringChooserModel {
     return m_optionsValue;
   }
 
-  void SetDefault(wpi::StringRef val) override;
-  void SetSelected(wpi::StringRef val) override;
-  void SetActive(wpi::StringRef val) override;
+  void SetDefault(std::string_view val) override;
+  void SetSelected(std::string_view val) override;
+  void SetActive(std::string_view val) override;
   void SetOptions(wpi::ArrayRef<std::string> val) override;
 
   void Update() override;
diff --git a/glass/src/libnt/native/include/glass/networktables/NTSubsystem.h b/glass/src/libnt/native/include/glass/networktables/NTSubsystem.h
index b134e95497..c5862cfbd9 100644
--- a/glass/src/libnt/native/include/glass/networktables/NTSubsystem.h
+++ b/glass/src/libnt/native/include/glass/networktables/NTSubsystem.h
@@ -5,9 +5,9 @@
 #pragma once
 
 #include <string>
+#include <string_view>
 
 #include <ntcore_cpp.h>
-#include <wpi/StringRef.h>
 
 #include "glass/DataSource.h"
 #include "glass/networktables/NetworkTablesHelper.h"
@@ -18,8 +18,8 @@ class NTSubsystemModel : public SubsystemModel {
  public:
   static constexpr const char* kType = "Subsystem";
 
-  explicit NTSubsystemModel(wpi::StringRef path);
-  NTSubsystemModel(NT_Inst instance, wpi::StringRef path);
+  explicit NTSubsystemModel(std::string_view path);
+  NTSubsystemModel(NT_Inst instance, std::string_view path);
 
   const char* GetName() const override { return m_nameValue.c_str(); }
   const char* GetDefaultCommand() const override {
diff --git a/glass/src/libnt/native/include/glass/networktables/NetworkTables.h b/glass/src/libnt/native/include/glass/networktables/NetworkTables.h
index e7dbbece83..e16ac3ad14 100644
--- a/glass/src/libnt/native/include/glass/networktables/NetworkTables.h
+++ b/glass/src/libnt/native/include/glass/networktables/NetworkTables.h
@@ -6,12 +6,12 @@
 
 #include <memory>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <ntcore_cpp.h>
 #include <wpi/DenseMap.h>
 #include <wpi/STLExtras.h>
-#include <wpi/StringRef.h>
 
 #include "glass/Model.h"
 #include "glass/View.h"
@@ -47,7 +47,7 @@ class NetworkTablesModel : public Model {
   };
 
   struct TreeNode {
-    explicit TreeNode(wpi::StringRef name) : name{name} {}
+    explicit TreeNode(std::string_view name) : name{name} {}
 
     /** Short name (e.g. of just this node) */
     std::string name;
diff --git a/glass/src/libnt/native/include/glass/networktables/NetworkTablesHelper.h b/glass/src/libnt/native/include/glass/networktables/NetworkTablesHelper.h
index b241c6efb8..aba32525c8 100644
--- a/glass/src/libnt/native/include/glass/networktables/NetworkTablesHelper.h
+++ b/glass/src/libnt/native/include/glass/networktables/NetworkTablesHelper.h
@@ -4,11 +4,10 @@
 
 #pragma once
 
+#include <string_view>
 #include <vector>
 
 #include <ntcore_cpp.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 
 namespace glass {
 
@@ -23,7 +22,7 @@ class NetworkTablesHelper {
   NT_Inst GetInstance() const { return m_inst; }
   NT_EntryListenerPoller GetPoller() const { return m_poller; }
 
-  NT_Entry GetEntry(const wpi::Twine& name) const {
+  NT_Entry GetEntry(std::string_view name) const {
     return nt::GetEntry(m_inst, name);
   }
 
@@ -36,7 +35,7 @@ class NetworkTablesHelper {
     return nt::AddPolledEntryListener(m_poller, entry, flags);
   }
 
-  NT_EntryListener AddListener(const wpi::Twine& prefix,
+  NT_EntryListener AddListener(std::string_view prefix,
                                unsigned int flags = kDefaultListenerFlags) {
     return nt::AddPolledEntryListener(m_poller, prefix, flags);
   }
diff --git a/glass/src/libnt/native/include/glass/networktables/NetworkTablesProvider.h b/glass/src/libnt/native/include/glass/networktables/NetworkTablesProvider.h
index cf97e6cf1a..17374cae9e 100644
--- a/glass/src/libnt/native/include/glass/networktables/NetworkTablesProvider.h
+++ b/glass/src/libnt/native/include/glass/networktables/NetworkTablesProvider.h
@@ -6,12 +6,11 @@
 
 #include <functional>
 #include <memory>
+#include <string_view>
 #include <vector>
 
 #include <ntcore_cpp.h>
 #include <wpi/StringMap.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 
 #include "glass/Model.h"
 #include "glass/Provider.h"
@@ -42,8 +41,8 @@ class NetworkTablesProvider : private Provider<detail::NTProviderFunctions> {
   using Provider::CreateModelFunc;
   using Provider::CreateViewFunc;
 
-  explicit NetworkTablesProvider(const wpi::Twine& iniName);
-  NetworkTablesProvider(const wpi::Twine& iniName, NT_Inst inst);
+  explicit NetworkTablesProvider(std::string_view iniName);
+  NetworkTablesProvider(std::string_view iniName, NT_Inst inst);
 
   /**
    * Get the NetworkTables instance being used for this provider.
@@ -70,7 +69,7 @@ class NetworkTablesProvider : private Provider<detail::NTProviderFunctions> {
    * @param createModel functor to create model
    * @param createView functor to create view
    */
-  void Register(wpi::StringRef typeName, CreateModelFunc createModel,
+  void Register(std::string_view typeName, CreateModelFunc createModel,
                 CreateViewFunc createView);
 
   using WindowManager::AddWindow;
@@ -92,7 +91,7 @@ class NetworkTablesProvider : private Provider<detail::NTProviderFunctions> {
   wpi::StringMap<Builder> m_typeMap;
 
   struct Entry : public ModelEntry {
-    Entry(NT_Entry typeEntry, wpi::StringRef name, const Builder& builder)
+    Entry(NT_Entry typeEntry, std::string_view name, const Builder& builder)
         : ModelEntry{name, [](NT_Inst, const char*) { return true; },
                      builder.createModel},
           typeEntry{typeEntry} {}
@@ -102,7 +101,7 @@ class NetworkTablesProvider : private Provider<detail::NTProviderFunctions> {
   void Show(ViewEntry* entry, Window* window) override;
 
   ViewEntry* GetOrCreateView(const Builder& builder, NT_Entry typeEntry,
-                             wpi::StringRef name);
+                             std::string_view name);
 };
 
 /**
diff --git a/hal/.styleguide b/hal/.styleguide
index 49d4e29e24..5f7d6e3d7a 100644
--- a/hal/.styleguide
+++ b/hal/.styleguide
@@ -30,6 +30,7 @@ repoRootNameOverride {
 includeOtherLibs {
   ^FRC_FPGA_ChipObject/
   ^FRC_NetworkCommunication/
+  ^fmt/
   ^i2clib/
   ^llvm/
   ^opencv2/
diff --git a/hal/src/main/native/athena/AddressableLED.cpp b/hal/src/main/native/athena/AddressableLED.cpp
index 864c08ce07..74a323a46d 100644
--- a/hal/src/main/native/athena/AddressableLED.cpp
+++ b/hal/src/main/native/athena/AddressableLED.cpp
@@ -7,6 +7,7 @@
 #include <cstring>
 
 #include <FRC_FPGA_ChipObject/fpgainterfacecapi/NiFpga_HMB.h>
+#include <fmt/format.h>
 
 #include "ConstantsInternal.h"
 #include "DigitalInternal.h"
@@ -145,9 +146,11 @@ void HAL_SetAddressableLEDLength(HAL_AddressableLEDHandle handle,
 
   if (length > HAL_kAddressableLEDMaxLength || length < 0) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status, "LED length must be less than or equal to " +
-                                  wpi::Twine(HAL_kAddressableLEDMaxLength) +
-                                  ". " + wpi::Twine(length) + " was requested");
+    hal::SetLastError(
+        status,
+        fmt::format(
+            "LED length must be less than or equal to {}. {} was requested",
+            HAL_kAddressableLEDMaxLength, length));
     return;
   }
 
@@ -179,9 +182,11 @@ void HAL_WriteAddressableLEDData(HAL_AddressableLEDHandle handle,
 
   if (length > led->stringLength || length < 0) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status, "Data length must be less than or equal to " +
-                                  wpi::Twine(led->stringLength) + ". " +
-                                  wpi::Twine(length) + " was requested");
+    hal::SetLastError(
+        status,
+        fmt::format(
+            "Data length must be less than or equal to {}. {} was requested",
+            led->stringLength, length));
     return;
   }
 
diff --git a/hal/src/main/native/athena/AnalogGyro.cpp b/hal/src/main/native/athena/AnalogGyro.cpp
index 83bc42f0be..19f26ddd7b 100644
--- a/hal/src/main/native/athena/AnalogGyro.cpp
+++ b/hal/src/main/native/athena/AnalogGyro.cpp
@@ -7,7 +7,7 @@
 #include <string>
 #include <thread>
 
-#include <wpi/raw_ostream.h>
+#include <fmt/format.h>
 
 #include "AnalogInternal.h"
 #include "HALInitializer.h"
@@ -193,8 +193,8 @@ void HAL_CalibrateAnalogGyro(HAL_GyroHandle handle, int32_t* status) {
   if (*status != 0) {
     return;
   }
-  wpi::outs() << "Calibrating analog gyro for " << kCalibrationSampleTime
-              << " seconds." << '\n';
+  fmt::print("Calibrating analog gyro for {} seconds.\n",
+             kCalibrationSampleTime);
   Wait(kCalibrationSampleTime);
 
   int64_t value;
diff --git a/hal/src/main/native/athena/CTREPCM.cpp b/hal/src/main/native/athena/CTREPCM.cpp
index fc079011e3..07aa48e1cc 100644
--- a/hal/src/main/native/athena/CTREPCM.cpp
+++ b/hal/src/main/native/athena/CTREPCM.cpp
@@ -4,6 +4,8 @@
 
 #include "hal/CTREPCM.h"
 
+#include <fmt/format.h>
+
 #include "HALInitializer.h"
 #include "HALInternal.h"
 #include "PortsInternal.h"
@@ -342,8 +344,9 @@ void HAL_FireCTREPCMOneShot(HAL_CTREPCMHandle handle, int32_t index,
                             int32_t* status) {
   if (index > 7 || index < 0) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status, "Only [0-7] are valid index values. Requested " +
-                                  wpi::Twine(index));
+    hal::SetLastError(
+        status,
+        fmt::format("Only [0-7] are valid index values. Requested {}", index));
     return;
   }
 
@@ -373,8 +376,9 @@ void HAL_SetCTREPCMOneShotDuration(HAL_CTREPCMHandle handle, int32_t index,
                                    int32_t durMs, int32_t* status) {
   if (index > 7 || index < 0) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status, "Only [0-7] are valid index values. Requested " +
-                                  wpi::Twine(index));
+    hal::SetLastError(
+        status,
+        fmt::format("Only [0-7] are valid index values. Requested {}", index));
     return;
   }
 
diff --git a/hal/src/main/native/athena/Counter.cpp b/hal/src/main/native/athena/Counter.cpp
index d6a278ce74..7f84df88ff 100644
--- a/hal/src/main/native/athena/Counter.cpp
+++ b/hal/src/main/native/athena/Counter.cpp
@@ -4,6 +4,8 @@
 
 #include "hal/Counter.h"
 
+#include <fmt/format.h>
+
 #include "ConstantsInternal.h"
 #include "DigitalInternal.h"
 #include "HALInitializer.h"
@@ -264,10 +266,9 @@ void HAL_SetCounterSamplesToAverage(HAL_CounterHandle counterHandle,
   }
   if (samplesToAverage < 1 || samplesToAverage > 127) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(
-        status,
-        "Samples to average must be between 1 and 127 inclusive. Requested " +
-            wpi::Twine(samplesToAverage));
+    hal::SetLastError(status, fmt::format("Samples to average must be between "
+                                          "1 and 127 inclusive. Requested {}",
+                                          samplesToAverage));
     return;
   }
   counter->counter->writeTimerConfig_AverageSize(samplesToAverage, status);
diff --git a/hal/src/main/native/athena/DIO.cpp b/hal/src/main/native/athena/DIO.cpp
index 75909a0702..45723597a8 100644
--- a/hal/src/main/native/athena/DIO.cpp
+++ b/hal/src/main/native/athena/DIO.cpp
@@ -5,10 +5,9 @@
 #include "hal/DIO.h"
 
 #include <cmath>
+#include <cstdio>
 #include <thread>
 
-#include <wpi/raw_ostream.h>
-
 #include "DigitalInternal.h"
 #include "HALInitializer.h"
 #include "HALInternal.h"
@@ -143,8 +142,8 @@ void HAL_FreeDIOPort(HAL_DigitalHandle dioPortHandle) {
   while (port.use_count() != 1) {
     auto current = hal::fpga_clock::now();
     if (start + std::chrono::seconds(1) < current) {
-      wpi::outs() << "DIO handle free timeout\n";
-      wpi::outs().flush();
+      std::puts("DIO handle free timeout");
+      std::fflush(stdout);
       break;
     }
     std::this_thread::yield();
diff --git a/hal/src/main/native/athena/Encoder.cpp b/hal/src/main/native/athena/Encoder.cpp
index 10556844f6..d5a3d38c94 100644
--- a/hal/src/main/native/athena/Encoder.cpp
+++ b/hal/src/main/native/athena/Encoder.cpp
@@ -4,6 +4,8 @@
 
 #include "hal/Encoder.h"
 
+#include <fmt/format.h>
+
 #include "EncoderInternal.h"
 #include "FPGAEncoder.h"
 #include "HALInitializer.h"
@@ -47,9 +49,8 @@ Encoder::Encoder(HAL_Handle digitalSourceHandleA,
     }
     default:
       *status = PARAMETER_OUT_OF_RANGE;
-      hal::SetLastError(status, "Encoding type " +
-                                    wpi::Twine(static_cast<int>(encodingType)) +
-                                    " invalid.");
+      hal::SetLastError(status, fmt::format("Encoding type {} invalid.",
+                                            static_cast<int>(encodingType)));
       return;
   }
 }
@@ -185,10 +186,9 @@ void Encoder::SetReverseDirection(bool reverseDirection, int32_t* status) {
 void Encoder::SetSamplesToAverage(int32_t samplesToAverage, int32_t* status) {
   if (samplesToAverage < 1 || samplesToAverage > 127) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(
-        status,
-        "Samples to average must be between 1 and 127 inclusive. Requested " +
-            wpi::Twine(samplesToAverage));
+    hal::SetLastError(status, fmt::format("Samples to average must be between "
+                                          "1 and 127 inclusive. Requested {}",
+                                          samplesToAverage));
     return;
   }
   if (m_counter) {
diff --git a/hal/src/main/native/athena/FPGAEncoder.cpp b/hal/src/main/native/athena/FPGAEncoder.cpp
index 3bfe9d9a41..9965d43cb0 100644
--- a/hal/src/main/native/athena/FPGAEncoder.cpp
+++ b/hal/src/main/native/athena/FPGAEncoder.cpp
@@ -6,6 +6,8 @@
 
 #include <memory>
 
+#include <fmt/format.h>
+
 #include "DigitalInternal.h"
 #include "HALInitializer.h"
 #include "HALInternal.h"
@@ -194,10 +196,9 @@ void HAL_SetFPGAEncoderSamplesToAverage(HAL_FPGAEncoderHandle fpgaEncoderHandle,
   }
   if (samplesToAverage < 1 || samplesToAverage > 127) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(
-        status,
-        "Samples to average must be between 1 and 127 inclusive. Requested " +
-            wpi::Twine(samplesToAverage));
+    hal::SetLastError(status, fmt::format("Samples to average must be between "
+                                          "1 and 127 inclusive. Requested {}",
+                                          samplesToAverage));
     return;
   }
   encoder->encoder->writeTimerConfig_AverageSize(samplesToAverage, status);
diff --git a/hal/src/main/native/athena/FRCDriverStation.cpp b/hal/src/main/native/athena/FRCDriverStation.cpp
index 40c2f24baa..55b86e7bc8 100644
--- a/hal/src/main/native/athena/FRCDriverStation.cpp
+++ b/hal/src/main/native/athena/FRCDriverStation.cpp
@@ -7,13 +7,15 @@
 #include <cstdlib>
 #include <cstring>
 #include <limits>
+#include <string>
+#include <string_view>
 
 #include <FRC_NetworkCommunication/FRCComm.h>
 #include <FRC_NetworkCommunication/NetCommRPCProxy_Occur.h>
+#include <fmt/format.h>
 #include <wpi/SafeThread.h>
 #include <wpi/condition_variable.h>
 #include <wpi/mutex.h>
-#include <wpi/raw_ostream.h>
 
 #include "hal/DriverStation.h"
 
@@ -161,9 +163,9 @@ int32_t HAL_SendError(HAL_Bool isError, int32_t errorCode, HAL_Bool isLVCode,
   }
   int retval = 0;
   if (i == KEEP_MSGS || (curTime - prevMsgTime[i]) >= std::chrono::seconds(1)) {
-    wpi::StringRef detailsRef{details};
-    wpi::StringRef locationRef{location};
-    wpi::StringRef callStackRef{callStack};
+    std::string_view detailsRef{details};
+    std::string_view locationRef{location};
+    std::string_view callStackRef{callStack};
 
     // 1 tag, 4 timestamp, 2 seqnum
     // 2 numOccur, 4 error code, 1 flags, 6 strlen
@@ -199,14 +201,16 @@ int32_t HAL_SendError(HAL_Bool isError, int32_t errorCode, HAL_Bool isLVCode,
                                                   newCallStack.c_str());
     }
     if (printMsg) {
+      fmt::memory_buffer buf;
       if (location && location[0] != '\0') {
-        wpi::errs() << (isError ? "Error" : "Warning") << " at " << location
-                    << ": ";
+        fmt::format_to(buf, "{} at {}: ", isError ? "Error" : "Warning",
+                       location);
       }
-      wpi::errs() << details << "\n";
+      fmt::format_to(buf, "{}\n", details);
       if (callStack && callStack[0] != '\0') {
-        wpi::errs() << callStack << "\n";
+        fmt::format_to(buf, "{}\n", callStack);
       }
+      std::fwrite(buf.data(), buf.size(), 1, stderr);
     }
     if (i == KEEP_MSGS) {
       // replace the oldest one
@@ -226,7 +230,7 @@ int32_t HAL_SendError(HAL_Bool isError, int32_t errorCode, HAL_Bool isLVCode,
 }
 
 int32_t HAL_SendConsoleLine(const char* line) {
-  wpi::StringRef lineRef{line};
+  std::string_view lineRef{line};
   if (lineRef.size() <= 65535) {
     // Send directly
     return FRC_NetworkCommunication_sendConsoleLine(line);
diff --git a/hal/src/main/native/athena/HAL.cpp b/hal/src/main/native/athena/HAL.cpp
index 386953669d..e99aa0f6a7 100644
--- a/hal/src/main/native/athena/HAL.cpp
+++ b/hal/src/main/native/athena/HAL.cpp
@@ -9,6 +9,7 @@
 #include <unistd.h>
 
 #include <atomic>
+#include <cstdio>
 #include <cstdlib>
 #include <fstream>
 #include <thread>
@@ -16,8 +17,8 @@
 #include <FRC_NetworkCommunication/FRCComm.h>
 #include <FRC_NetworkCommunication/LoadOut.h>
 #include <FRC_NetworkCommunication/UsageReporting.h>
+#include <fmt/format.h>
 #include <wpi/mutex.h>
-#include <wpi/raw_ostream.h>
 #include <wpi/timestamp.h>
 
 #include "HALInitializer.h"
@@ -330,18 +331,19 @@ static bool killExistingProgram(int timeout, int mode) {
     // see if the pid is around, but we don't want to mess with init id=1, or
     // ourselves
     if (pid >= 2 && kill(pid, 0) == 0 && pid != getpid()) {
-      wpi::outs() << "Killing previously running FRC program...\n";
+      std::puts("Killing previously running FRC program...");
       kill(pid, SIGTERM);  // try to kill it
       std::this_thread::sleep_for(std::chrono::milliseconds(timeout));
       if (kill(pid, 0) == 0) {
         // still not successful
-        wpi::outs() << "FRC pid " << pid << " did not die within " << timeout
-                    << "ms. Force killing with kill -9\n";
+        fmt::print(
+            "FRC pid {} did not die within {} ms. Force killing with kill -9\n",
+            pid, timeout);
         // Force kill -9
         auto forceKill = kill(pid, SIGKILL);
         if (forceKill != 0) {
           auto errorMsg = std::strerror(forceKill);
-          wpi::outs() << "Kill -9 error: " << errorMsg << "\n";
+          fmt::print("Kill -9 error: {}\n", errorMsg);
         }
         // Give a bit of time for the kill to take place
         std::this_thread::sleep_for(std::chrono::milliseconds(250));
@@ -378,7 +380,6 @@ HAL_Bool HAL_Initialize(int32_t timeout, int32_t mode) {
 
   setlinebuf(stdin);
   setlinebuf(stdout);
-  wpi::outs().SetUnbuffered();
 
   prctl(PR_SET_PDEATHSIG, SIGTERM);
 
@@ -412,11 +413,11 @@ HAL_Bool HAL_Initialize(int32_t timeout, int32_t mode) {
     int32_t status = 0;
     uint64_t rv = HAL_GetFPGATime(&status);
     if (status != 0) {
-      wpi::errs()
-          << "Call to HAL_GetFPGATime failed in wpi::Now() with status "
-          << status
-          << ". Initialization might have failed. Time will not be correct\n";
-      wpi::errs().flush();
+      fmt::print(stderr,
+                 "Call to HAL_GetFPGATime failed in wpi::Now() with status {}. "
+                 "Initialization might have failed. Time will not be correct\n",
+                 status);
+      std::fflush(stderr);
       return 0u;
     }
     return rv;
diff --git a/hal/src/main/native/athena/HALInternal.h b/hal/src/main/native/athena/HALInternal.h
index b1a2d1dfd5..64a0dca368 100644
--- a/hal/src/main/native/athena/HALInternal.h
+++ b/hal/src/main/native/athena/HALInternal.h
@@ -6,15 +6,15 @@
 
 #include <stdint.h>
 
-#include <wpi/Twine.h>
+#include <string_view>
 
 namespace hal {
 void ReleaseFPGAInterrupt(int32_t interruptNumber);
-void SetLastError(int32_t* status, const wpi::Twine& value);
-void SetLastErrorIndexOutOfRange(int32_t* status, const wpi::Twine& message,
+void SetLastError(int32_t* status, std::string_view value);
+void SetLastErrorIndexOutOfRange(int32_t* status, std::string_view message,
                                  int32_t minimum, int32_t maximum,
                                  int32_t channel);
-void SetLastErrorPreviouslyAllocated(int32_t* status, const wpi::Twine& message,
+void SetLastErrorPreviouslyAllocated(int32_t* status, std::string_view message,
                                      int32_t channel,
-                                     const wpi::Twine& previousAllocation);
+                                     std::string_view previousAllocation);
 }  // namespace hal
diff --git a/hal/src/main/native/athena/I2C.cpp b/hal/src/main/native/athena/I2C.cpp
index 9af13ed46f..6e7f89bead 100644
--- a/hal/src/main/native/athena/I2C.cpp
+++ b/hal/src/main/native/athena/I2C.cpp
@@ -12,6 +12,8 @@
 
 #include <cstring>
 
+#include <fmt/format.h>
+
 #include "DigitalInternal.h"
 #include "HALInitializer.h"
 #include "hal/DIO.h"
@@ -56,7 +58,7 @@ void HAL_InitializeI2C(HAL_I2CPort port, int32_t* status) {
     }
     int handle = open("/dev/i2c-2", O_RDWR);
     if (handle < 0) {
-      std::printf("Failed to open onboard i2c bus: %s\n", std::strerror(errno));
+      fmt::print("Failed to open onboard i2c bus: {}\n", std::strerror(errno));
       return;
     }
     i2COnBoardHandle = handle;
@@ -79,7 +81,7 @@ void HAL_InitializeI2C(HAL_I2CPort port, int32_t* status) {
         digitalSystem->readEnableMXPSpecialFunction(status) | 0xC000, status);
     int handle = open("/dev/i2c-1", O_RDWR);
     if (handle < 0) {
-      std::printf("Failed to open MXP i2c bus: %s\n", std::strerror(errno));
+      fmt::print("Failed to open MXP i2c bus: {}\n", std::strerror(errno));
       return;
     }
     i2CMXPHandle = handle;
diff --git a/hal/src/main/native/athena/PDP.cpp b/hal/src/main/native/athena/PDP.cpp
index 0cdf30f831..3771bcef9b 100644
--- a/hal/src/main/native/athena/PDP.cpp
+++ b/hal/src/main/native/athena/PDP.cpp
@@ -4,6 +4,7 @@
 
 #include "hal/PDP.h"
 
+#include <fmt/format.h>
 #include <wpi/mutex.h>
 
 #include "HALInitializer.h"
@@ -118,7 +119,7 @@ HAL_PDPHandle HAL_InitializePDP(int32_t module, int32_t* status) {
   hal::init::CheckInit();
   if (!HAL_CheckPDPModule(module)) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status, "Invalid pdp module " + wpi::Twine(module));
+    hal::SetLastError(status, fmt::format("Invalid pdp module {}", module));
     return HAL_kInvalidHandle;
   }
 
@@ -194,7 +195,7 @@ double HAL_GetPDPChannelCurrent(HAL_PDPHandle handle, int32_t channel,
                                 int32_t* status) {
   if (!HAL_CheckPDPChannel(channel)) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status, "Invalid pdp channel " + wpi::Twine(channel));
+    hal::SetLastError(status, fmt::format("Invalid pdp channel {}", channel));
     return 0;
   }
 
diff --git a/hal/src/main/native/athena/PWM.cpp b/hal/src/main/native/athena/PWM.cpp
index bf9773a6a2..6bb0fce09c 100644
--- a/hal/src/main/native/athena/PWM.cpp
+++ b/hal/src/main/native/athena/PWM.cpp
@@ -4,11 +4,11 @@
 
 #include "hal/PWM.h"
 
+#include <algorithm>
 #include <cmath>
+#include <cstdio>
 #include <thread>
 
-#include <wpi/raw_ostream.h>
-
 #include "ConstantsInternal.h"
 #include "DigitalInternal.h"
 #include "HALInitializer.h"
@@ -138,8 +138,8 @@ void HAL_FreePWMPort(HAL_DigitalHandle pwmPortHandle, int32_t* status) {
   while (port.use_count() != 1) {
     auto current = hal::fpga_clock::now();
     if (start + std::chrono::seconds(1) < current) {
-      wpi::outs() << "PWM handle free timeout\n";
-      wpi::outs().flush();
+      std::puts("PWM handle free timeout");
+      std::fflush(stdout);
       break;
     }
     std::this_thread::yield();
diff --git a/hal/src/main/native/athena/SPI.cpp b/hal/src/main/native/athena/SPI.cpp
index 090c53378e..1121fd88dd 100644
--- a/hal/src/main/native/athena/SPI.cpp
+++ b/hal/src/main/native/athena/SPI.cpp
@@ -11,10 +11,11 @@
 
 #include <array>
 #include <atomic>
+#include <cstdio>
 #include <cstring>
 
+#include <fmt/format.h>
 #include <wpi/mutex.h>
-#include <wpi/raw_ostream.h>
 
 #include "DigitalInternal.h"
 #include "HALInitializer.h"
@@ -78,14 +79,14 @@ static void CommonSPIPortInit(int32_t* status) {
     if ((digitalHandles[3] = HAL_InitializeDIOPort(createPortHandleForSPI(29),
                                                    false, nullptr, status)) ==
         HAL_kInvalidHandle) {
-      std::printf("Failed to allocate DIO 29 (MISO)\n");
+      std::puts("Failed to allocate DIO 29 (MISO)");
       return;
     }
     // MOSI
     if ((digitalHandles[4] = HAL_InitializeDIOPort(createPortHandleForSPI(30),
                                                    false, nullptr, status)) ==
         HAL_kInvalidHandle) {
-      std::printf("Failed to allocate DIO 30 (MOSI)\n");
+      std::puts("Failed to allocate DIO 30 (MOSI)");
       HAL_FreeDIOPort(digitalHandles[3]);  // free the first port allocated
       return;
     }
@@ -104,9 +105,10 @@ void HAL_InitializeSPI(HAL_SPIPort port, int32_t* status) {
   hal::init::CheckInit();
   if (port < 0 || port >= kSpiMaxHandles) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status, "Serial port must be between 0 and " +
-                                  wpi::Twine(kSpiMaxHandles) + ". Requested " +
-                                  wpi::Twine(static_cast<int>(port)));
+    hal::SetLastError(
+        status,
+        fmt::format("Serial port must be between 0 and {}. Requested {}",
+                    kSpiMaxHandles, static_cast<int>(port)));
     return;
   }
 
@@ -123,8 +125,8 @@ void HAL_InitializeSPI(HAL_SPIPort port, int32_t* status) {
       // CS0 is not a DIO port, so nothing to allocate
       handle = open("/dev/spidev0.0", O_RDWR);
       if (handle < 0) {
-        std::printf("Failed to open SPI port %d: %s\n", port,
-                    std::strerror(errno));
+        fmt::print("Failed to open SPI port {}: {}\n", port,
+                   std::strerror(errno));
         CommonSPIPortFree();
         return;
       }
@@ -139,14 +141,14 @@ void HAL_InitializeSPI(HAL_SPIPort port, int32_t* status) {
       if ((digitalHandles[0] = HAL_InitializeDIOPort(createPortHandleForSPI(26),
                                                      false, nullptr, status)) ==
           HAL_kInvalidHandle) {
-        std::printf("Failed to allocate DIO 26 (CS1)\n");
+        std::puts("Failed to allocate DIO 26 (CS1)");
         CommonSPIPortFree();
         return;
       }
       handle = open("/dev/spidev0.1", O_RDWR);
       if (handle < 0) {
-        std::printf("Failed to open SPI port %d: %s\n", port,
-                    std::strerror(errno));
+        fmt::print("Failed to open SPI port {}: {}\n", port,
+                   std::strerror(errno));
         CommonSPIPortFree();
         HAL_FreeDIOPort(digitalHandles[0]);
         return;
@@ -162,14 +164,14 @@ void HAL_InitializeSPI(HAL_SPIPort port, int32_t* status) {
       if ((digitalHandles[1] = HAL_InitializeDIOPort(createPortHandleForSPI(27),
                                                      false, nullptr, status)) ==
           HAL_kInvalidHandle) {
-        std::printf("Failed to allocate DIO 27 (CS2)\n");
+        std::puts("Failed to allocate DIO 27 (CS2)");
         CommonSPIPortFree();
         return;
       }
       handle = open("/dev/spidev0.2", O_RDWR);
       if (handle < 0) {
-        std::printf("Failed to open SPI port %d: %s\n", port,
-                    std::strerror(errno));
+        fmt::print("Failed to open SPI port {}: {}\n", port,
+                   std::strerror(errno));
         CommonSPIPortFree();
         HAL_FreeDIOPort(digitalHandles[1]);
         return;
@@ -185,14 +187,14 @@ void HAL_InitializeSPI(HAL_SPIPort port, int32_t* status) {
       if ((digitalHandles[2] = HAL_InitializeDIOPort(createPortHandleForSPI(28),
                                                      false, nullptr, status)) ==
           HAL_kInvalidHandle) {
-        std::printf("Failed to allocate DIO 28 (CS3)\n");
+        std::puts("Failed to allocate DIO 28 (CS3)");
         CommonSPIPortFree();
         return;
       }
       handle = open("/dev/spidev0.3", O_RDWR);
       if (handle < 0) {
-        std::printf("Failed to open SPI port %d: %s\n", port,
-                    std::strerror(errno));
+        fmt::print("Failed to open SPI port {}: {}\n", port,
+                   std::strerror(errno));
         CommonSPIPortFree();
         HAL_FreeDIOPort(digitalHandles[2]);
         return;
@@ -207,20 +209,20 @@ void HAL_InitializeSPI(HAL_SPIPort port, int32_t* status) {
       if ((digitalHandles[5] = HAL_InitializeDIOPort(createPortHandleForSPI(14),
                                                      false, nullptr, status)) ==
           HAL_kInvalidHandle) {
-        wpi::outs() << "Failed to allocate DIO 14\n";
+        std::puts("Failed to allocate DIO 14");
         return;
       }
       if ((digitalHandles[6] = HAL_InitializeDIOPort(createPortHandleForSPI(15),
                                                      false, nullptr, status)) ==
           HAL_kInvalidHandle) {
-        wpi::outs() << "Failed to allocate DIO 15\n";
+        std::puts("Failed to allocate DIO 15");
         HAL_FreeDIOPort(digitalHandles[5]);  // free the first port allocated
         return;
       }
       if ((digitalHandles[7] = HAL_InitializeDIOPort(createPortHandleForSPI(16),
                                                      false, nullptr, status)) ==
           HAL_kInvalidHandle) {
-        wpi::outs() << "Failed to allocate DIO 16\n";
+        std::puts("Failed to allocate DIO 16");
         HAL_FreeDIOPort(digitalHandles[5]);  // free the first port allocated
         HAL_FreeDIOPort(digitalHandles[6]);  // free the second port allocated
         return;
@@ -228,7 +230,7 @@ void HAL_InitializeSPI(HAL_SPIPort port, int32_t* status) {
       if ((digitalHandles[8] = HAL_InitializeDIOPort(createPortHandleForSPI(17),
                                                      false, nullptr, status)) ==
           HAL_kInvalidHandle) {
-        wpi::outs() << "Failed to allocate DIO 17\n";
+        std::puts("Failed to allocate DIO 17");
         HAL_FreeDIOPort(digitalHandles[5]);  // free the first port allocated
         HAL_FreeDIOPort(digitalHandles[6]);  // free the second port allocated
         HAL_FreeDIOPort(digitalHandles[7]);  // free the third port allocated
@@ -238,8 +240,8 @@ void HAL_InitializeSPI(HAL_SPIPort port, int32_t* status) {
           digitalSystem->readEnableMXPSpecialFunction(status) | 0x00F0, status);
       handle = open("/dev/spidev1.0", O_RDWR);
       if (handle < 0) {
-        std::printf("Failed to open SPI port %d: %s\n", port,
-                    std::strerror(errno));
+        fmt::print("Failed to open SPI port {}: {}\n", port,
+                   std::strerror(errno));
         HAL_FreeDIOPort(digitalHandles[5]);  // free the first port allocated
         HAL_FreeDIOPort(digitalHandles[6]);  // free the second port allocated
         HAL_FreeDIOPort(digitalHandles[7]);  // free the third port allocated
@@ -251,7 +253,7 @@ void HAL_InitializeSPI(HAL_SPIPort port, int32_t* status) {
     default:
       *status = PARAMETER_OUT_OF_RANGE;
       hal::SetLastError(
-          status, "Invalid SPI port " + wpi::Twine(static_cast<int>(port)));
+          status, fmt::format("Invalid SPI port {}", static_cast<int>(port)));
       break;
   }
 }
@@ -380,9 +382,10 @@ void HAL_SetSPIOpts(HAL_SPIPort port, HAL_Bool msbFirst,
 void HAL_SetSPIChipSelectActiveHigh(HAL_SPIPort port, int32_t* status) {
   if (port < 0 || port >= kSpiMaxHandles) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status, "Serial port must be between 0 and " +
-                                  wpi::Twine(kSpiMaxHandles) + ". Requested " +
-                                  wpi::Twine(static_cast<int>(port)));
+    hal::SetLastError(
+        status,
+        fmt::format("Serial port must be between 0 and {}. Requested {}",
+                    kSpiMaxHandles, static_cast<int>(port)));
     return;
   }
 
@@ -398,9 +401,10 @@ void HAL_SetSPIChipSelectActiveHigh(HAL_SPIPort port, int32_t* status) {
 void HAL_SetSPIChipSelectActiveLow(HAL_SPIPort port, int32_t* status) {
   if (port < 0 || port >= kSpiMaxHandles) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status, "Serial port must be between 0 and " +
-                                  wpi::Twine(kSpiMaxHandles) + ". Requested " +
-                                  wpi::Twine(static_cast<int>(port)));
+    hal::SetLastError(
+        status,
+        fmt::format("Serial port must be between 0 and {}. Requested {}",
+                    kSpiMaxHandles, static_cast<int>(port)));
     return;
   }
 
@@ -465,9 +469,10 @@ void HAL_SetSPIHandle(HAL_SPIPort port, int32_t handle) {
 void HAL_InitSPIAuto(HAL_SPIPort port, int32_t bufferSize, int32_t* status) {
   if (port < 0 || port >= kSpiMaxHandles) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status, "Serial port must be between 0 and " +
-                                  wpi::Twine(kSpiMaxHandles) + ". Requested " +
-                                  wpi::Twine(static_cast<int>(port)));
+    hal::SetLastError(
+        status,
+        fmt::format("Serial port must be between 0 and {}. Requested {}",
+                    kSpiMaxHandles, static_cast<int>(port)));
     return;
   }
 
@@ -499,9 +504,10 @@ void HAL_InitSPIAuto(HAL_SPIPort port, int32_t bufferSize, int32_t* status) {
 void HAL_FreeSPIAuto(HAL_SPIPort port, int32_t* status) {
   if (port < 0 || port >= kSpiMaxHandles) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status, "Serial port must be between 0 and " +
-                                  wpi::Twine(kSpiMaxHandles) + ". Requested " +
-                                  wpi::Twine(static_cast<int>(port)));
+    hal::SetLastError(
+        status,
+        fmt::format("Serial port must be between 0 and {}. Requested {}",
+                    kSpiMaxHandles, static_cast<int>(port)));
     return;
   }
 
@@ -605,16 +611,20 @@ void HAL_SetSPIAutoTransmitData(HAL_SPIPort port, const uint8_t* dataToSend,
   if (dataSize < 0 || dataSize > 32) {
     *status = PARAMETER_OUT_OF_RANGE;
     hal::SetLastError(
-        status, "Data size must be between 0 and 32 inclusive. Requested " +
-                    wpi::Twine(dataSize));
+        status,
+        fmt::format(
+            "Data size must be between 0 and 32 inclusive. Requested {}",
+            dataSize));
     return;
   }
 
   if (zeroSize < 0 || zeroSize > 127) {
     *status = PARAMETER_OUT_OF_RANGE;
     hal::SetLastError(
-        status, "Zero size must be between 0 and 127 inclusive. Requested " +
-                    wpi::Twine(zeroSize));
+        status,
+        fmt::format(
+            "Zero size must be between 0 and 127 inclusive. Requested {}",
+            zeroSize));
     return;
   }
 
diff --git a/hal/src/main/native/athena/SerialPort.cpp b/hal/src/main/native/athena/SerialPort.cpp
index dfacbecc7c..0163f6e48f 100644
--- a/hal/src/main/native/athena/SerialPort.cpp
+++ b/hal/src/main/native/athena/SerialPort.cpp
@@ -19,6 +19,8 @@
 #include <string>
 #include <thread>
 
+#include <fmt/format.h>
+
 #include "HALInternal.h"
 #include "hal/cpp/SerialHelper.h"
 #include "hal/handles/HandlesInternal.h"
@@ -184,7 +186,7 @@ void HAL_SetSerialBaudRate(HAL_SerialPortHandle handle, int32_t baud,
     BAUDCASE(4000000)
     default:
       *status = PARAMETER_OUT_OF_RANGE;
-      hal::SetLastError(status, "Invalid BaudRate: " + wpi::Twine(baud));
+      hal::SetLastError(status, fmt::format("Invalid BaudRate: {}", baud));
       return;
   }
   int err = cfsetospeed(&port->tty, static_cast<speed_t>(port->baudRate));
@@ -227,7 +229,7 @@ void HAL_SetSerialDataBits(HAL_SerialPortHandle handle, int32_t bits,
       break;
     default:
       *status = PARAMETER_OUT_OF_RANGE;
-      hal::SetLastError(status, "Invalid data bits: " + wpi::Twine(bits));
+      hal::SetLastError(status, fmt::format("Invalid data bits: {}", bits));
       return;
   }
 
@@ -275,7 +277,7 @@ void HAL_SetSerialParity(HAL_SerialPortHandle handle, int32_t parity,
       break;
     default:
       *status = PARAMETER_OUT_OF_RANGE;
-      hal::SetLastError(status, "Invalid parity bits: " + wpi::Twine(parity));
+      hal::SetLastError(status, fmt::format("Invalid parity bits: {}", parity));
       return;
   }
 
@@ -303,7 +305,7 @@ void HAL_SetSerialStopBits(HAL_SerialPortHandle handle, int32_t stopBits,
       break;
     default:
       *status = PARAMETER_OUT_OF_RANGE;
-      hal::SetLastError(status, "Invalid stop bits: " + wpi::Twine(stopBits));
+      hal::SetLastError(status, fmt::format("Invalid stop bits: {}", stopBits));
       return;
   }
 
@@ -339,7 +341,7 @@ void HAL_SetSerialFlowControl(HAL_SerialPortHandle handle, int32_t flow,
       break;
     default:
       *status = PARAMETER_OUT_OF_RANGE;
-      hal::SetLastError(status, "Invalid fc bits: " + wpi::Twine(flow));
+      hal::SetLastError(status, fmt::format("Invalid fc bits: {}", flow));
       return;
   }
 
diff --git a/hal/src/main/native/athena/cpp/SerialHelper.cpp b/hal/src/main/native/athena/cpp/SerialHelper.cpp
index 361a0ea1a0..3831769a2e 100644
--- a/hal/src/main/native/athena/cpp/SerialHelper.cpp
+++ b/hal/src/main/native/athena/cpp/SerialHelper.cpp
@@ -7,8 +7,9 @@
 #include <algorithm>
 #include <cstdio>
 #include <cstring>
+#include <string_view>
 
-#include <wpi/StringRef.h>
+#include <wpi/StringExtras.h>
 #include <wpi/fs.h>
 
 #include "hal/Errors.h"
@@ -53,7 +54,7 @@ std::string SerialHelper::GetVISASerialPortName(HAL_SerialPort port,
     return "";
     // Error
   } else {
-    return m_visaResource[visaIndex].str();
+    return std::string{m_visaResource[visaIndex].str()};
   }
 }
 
@@ -80,7 +81,7 @@ std::string SerialHelper::GetOSSerialPortName(HAL_SerialPort port,
     return "";
     // Error
   } else {
-    return m_osResource[osIndex].str();
+    return std::string{m_osResource[osIndex].str()};
   }
 }
 
@@ -136,8 +137,8 @@ void SerialHelper::SortHubPathVector() {
   std::sort(m_sortedHubPath.begin(), m_sortedHubPath.end(),
             [](const wpi::SmallVectorImpl<char>& lhs,
                const wpi::SmallVectorImpl<char>& rhs) -> int {
-              wpi::StringRef lhsRef(lhs.begin(), lhs.size());
-              wpi::StringRef rhsRef(rhs.begin(), rhs.size());
+              std::string_view lhsRef(lhs.begin(), lhs.size());
+              std::string_view rhsRef(rhs.begin(), rhs.size());
               return lhsRef.compare(rhsRef);
             });
 }
@@ -147,9 +148,9 @@ void SerialHelper::CoiteratedSort(
   wpi::SmallVector<wpi::SmallString<16>, 4> sortedVec;
   for (auto& str : m_sortedHubPath) {
     for (size_t i = 0; i < m_unsortedHubPath.size(); i++) {
-      if (wpi::StringRef{m_unsortedHubPath[i].begin(),
-                         m_unsortedHubPath[i].size()}
-              .equals(wpi::StringRef{str.begin(), str.size()})) {
+      if (wpi::equals(std::string_view{m_unsortedHubPath[i].begin(),
+                                       m_unsortedHubPath[i].size()},
+                      std::string_view{str.begin(), str.size()})) {
         sortedVec.push_back(vec[i]);
         break;
       }
@@ -206,14 +207,14 @@ void SerialHelper::QueryHubPaths(int32_t* status) {
     *status = 0;
 
     // split until (/dev/
-    wpi::StringRef devNameRef = wpi::StringRef{osName}.split("(/dev/").second;
+    std::string_view devNameRef = wpi::split(osName, "(/dev/").second;
     // String not found, continue
-    if (devNameRef.equals(""))
+    if (wpi::equals(devNameRef, ""))
       continue;
 
     // Split at )
-    wpi::StringRef matchString = devNameRef.split(')').first;
-    if (matchString.equals(devNameRef))
+    std::string_view matchString = wpi::split(devNameRef, ')').first;
+    if (wpi::equals(matchString, devNameRef))
       continue;
 
     // Search directories to get a list of system accessors
@@ -223,7 +224,7 @@ void SerialHelper::QueryHubPaths(int32_t* status) {
     for (auto& p : fs::recursive_directory_iterator("/sys/devices/soc0", ec)) {
       if (ec)
         break;
-      std::string path = p.path().string();
+      std::string path = p.path();
       if (path.find("amba") == std::string::npos)
         continue;
       if (path.find("usb") == std::string::npos)
@@ -231,22 +232,22 @@ void SerialHelper::QueryHubPaths(int32_t* status) {
       if (path.find(matchString) == std::string::npos)
         continue;
 
-      wpi::SmallVector<wpi::StringRef, 16> pathSplitVec;
+      wpi::SmallVector<std::string_view, 16> pathSplitVec;
       // Split path into individual directories
-      wpi::StringRef{path}.split(pathSplitVec, '/', -1, false);
+      wpi::split(path, pathSplitVec, '/', -1, false);
 
       // Find each individual item index
       int findusb = -1;
       int findtty = -1;
       int findregex = -1;
       for (size_t i = 0; i < pathSplitVec.size(); i++) {
-        if (findusb == -1 && pathSplitVec[i].equals("usb1")) {
+        if (findusb == -1 && wpi::equals(pathSplitVec[i], "usb1")) {
           findusb = i;
         }
-        if (findtty == -1 && pathSplitVec[i].equals("tty")) {
+        if (findtty == -1 && wpi::equals(pathSplitVec[i], "tty")) {
           findtty = i;
         }
-        if (findregex == -1 && pathSplitVec[i].equals(matchString)) {
+        if (findregex == -1 && wpi::equals(pathSplitVec[i], matchString)) {
           findregex = i;
         }
       }
@@ -263,10 +264,10 @@ void SerialHelper::QueryHubPaths(int32_t* status) {
 
       // Add our devices to our list
       m_unsortedHubPath.emplace_back(
-          wpi::StringRef{pathSplitVec[hubIndex - 2]});
+          std::string_view{pathSplitVec[hubIndex - 2]});
       m_visaResource.emplace_back(desc);
       m_osResource.emplace_back(
-          wpi::StringRef{osName}.split("(").second.split(")").first);
+          wpi::split(wpi::split(osName, "(").second, ")").first);
       break;
     }
   }
@@ -291,8 +292,9 @@ int32_t SerialHelper::GetIndexForPort(HAL_SerialPort port, int32_t* status) {
   if (portString.empty()) {
     for (size_t i = 0; i < 2; i++) {
       // Remove all used ports
-      auto idx = std::find(m_sortedHubPath.begin(), m_sortedHubPath.end(),
-                           m_usbNames[i]);
+      auto idx = std::find_if(
+          m_sortedHubPath.begin(), m_sortedHubPath.end(),
+          [&](const auto& s) { return wpi::equals(s, m_usbNames[i]); });
       if (idx != m_sortedHubPath.end()) {
         // found
         m_sortedHubPath.erase(idx);
@@ -327,7 +329,7 @@ int32_t SerialHelper::GetIndexForPort(HAL_SerialPort port, int32_t* status) {
   int retIndex = -1;
 
   for (size_t i = 0; i < m_sortedHubPath.size(); i++) {
-    if (m_sortedHubPath[i].equals(portString)) {
+    if (wpi::equals(m_sortedHubPath[i], portString)) {
       retIndex = i;
       break;
     }
diff --git a/hal/src/main/native/cpp/ErrorHandling.cpp b/hal/src/main/native/cpp/ErrorHandling.cpp
index fa54e4676e..ad1b40b5bd 100644
--- a/hal/src/main/native/cpp/ErrorHandling.cpp
+++ b/hal/src/main/native/cpp/ErrorHandling.cpp
@@ -2,8 +2,8 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
+#include <fmt/format.h>
 #include <wpi/SmallString.h>
-#include <wpi/Twine.h>
 
 #include "hal/Errors.h"
 #include "hal/HALBase.h"
@@ -21,31 +21,30 @@ static LastErrorStorage& GetThreadLastError() {
 }
 
 namespace hal {
-void SetLastError(int32_t* status, const wpi::Twine& value) {
+void SetLastError(int32_t* status, std::string_view value) {
   LastErrorStorage& lastError = GetThreadLastError();
-  lastError.message.clear();
-  value.toVector(lastError.message);
+  lastError.message = value;
   lastError.status = *status;
   *status = HAL_USE_LAST_ERROR;
 }
 
-void SetLastErrorIndexOutOfRange(int32_t* status, const wpi::Twine& message,
+void SetLastErrorIndexOutOfRange(int32_t* status, std::string_view message,
                                  int32_t minimum, int32_t maximum,
                                  int32_t requested) {
-  SetLastError(status, message + "\n Status: " + wpi::Twine(*status) +
-                           "\n  Minimum: " + wpi::Twine(minimum) +
-                           " Maximum: " + wpi::Twine(maximum) +
-                           " Reequested: " + wpi::Twine(requested));
+  SetLastError(
+      status,
+      fmt::format("{}\n Status: {}\n  Minimum: {} Maximum: {} Requested: {}",
+                  message, *status, minimum, maximum, requested));
 }
 
-void SetLastErrorPreviouslyAllocated(int32_t* status, const wpi::Twine& message,
+void SetLastErrorPreviouslyAllocated(int32_t* status, std::string_view message,
                                      int32_t channel,
-                                     const wpi::Twine& previousAllocation) {
-  hal::SetLastError(
-      status,
-      message + " " + wpi::Twine(channel) +
-          " previously allocated.\nLocation of the previous allocation:\n" +
-          previousAllocation + "\nLocation of the current allocation:");
+                                     std::string_view previousAllocation) {
+  hal::SetLastError(status,
+                    fmt::format("{} {} previously allocated.\n"
+                                "Location of the previous allocation:\n{}\n"
+                                "Location of the current allocation:",
+                                message, channel, previousAllocation));
 }
 }  // namespace hal
 
diff --git a/hal/src/main/native/cpp/cpp/fpga_clock.cpp b/hal/src/main/native/cpp/cpp/fpga_clock.cpp
index 6ca623c257..550596a8ac 100644
--- a/hal/src/main/native/cpp/cpp/fpga_clock.cpp
+++ b/hal/src/main/native/cpp/cpp/fpga_clock.cpp
@@ -4,9 +4,10 @@
 
 #include "hal/cpp/fpga_clock.h"
 
+#include <cstdio>
 #include <limits>
 
-#include <wpi/raw_ostream.h>
+#include <fmt/format.h>
 
 #include "hal/HALBase.h"
 
@@ -19,11 +20,12 @@ fpga_clock::time_point fpga_clock::now() noexcept {
   int32_t status = 0;
   uint64_t currentTime = HAL_GetFPGATime(&status);
   if (status != 0) {
-    wpi::errs()
-        << "Call to HAL_GetFPGATime failed in fpga_clock::now() with status "
-        << status
-        << ". Initialization might have failed. Time will not be correct\n";
-    wpi::errs().flush();
+    fmt::print(
+        stderr,
+        "Call to HAL_GetFPGATime failed in fpga_clock::now() with status {}. "
+        "Initialization might have failed. Time will not be correct\n",
+        status);
+    std::fflush(stderr);
     return epoch();
   }
   return time_point(std::chrono::microseconds(currentTime));
diff --git a/hal/src/main/native/cpp/jni/CANAPIJNI.cpp b/hal/src/main/native/cpp/jni/CANAPIJNI.cpp
index 71804afa0c..106167abf0 100644
--- a/hal/src/main/native/cpp/jni/CANAPIJNI.cpp
+++ b/hal/src/main/native/cpp/jni/CANAPIJNI.cpp
@@ -6,9 +6,7 @@
 
 #include <cassert>
 
-#include <wpi/SmallString.h>
 #include <wpi/jni_util.h>
-#include <wpi/raw_ostream.h>
 
 #include "HALUtil.h"
 #include "edu_wpi_first_hal_CANAPIJNI.h"
diff --git a/hal/src/main/native/cpp/jni/CANJNI.cpp b/hal/src/main/native/cpp/jni/CANJNI.cpp
index b430012753..3eeedc6425 100644
--- a/hal/src/main/native/cpp/jni/CANJNI.cpp
+++ b/hal/src/main/native/cpp/jni/CANJNI.cpp
@@ -6,9 +6,7 @@
 
 #include <cassert>
 
-#include <wpi/SmallString.h>
 #include <wpi/jni_util.h>
-#include <wpi/raw_ostream.h>
 
 #include "HALUtil.h"
 #include "edu_wpi_first_hal_can_CANJNI.h"
@@ -65,8 +63,8 @@ Java_edu_wpi_first_hal_can_CANJNI_FRCNetCommCANSessionMuxReceiveMessage
     return nullptr;
   }
   return MakeJByteArray(env,
-                        wpi::StringRef{reinterpret_cast<const char*>(buffer),
-                                       static_cast<size_t>(dataSize)});
+                        std::string_view{reinterpret_cast<const char*>(buffer),
+                                         static_cast<size_t>(dataSize)});
 }
 
 /*
diff --git a/hal/src/main/native/cpp/jni/HAL.cpp b/hal/src/main/native/cpp/jni/HAL.cpp
index 4787ca85d6..4e260324c9 100644
--- a/hal/src/main/native/cpp/jni/HAL.cpp
+++ b/hal/src/main/native/cpp/jni/HAL.cpp
@@ -9,6 +9,7 @@
 #include <cassert>
 #include <cstring>
 
+#include <fmt/format.h>
 #include <wpi/jni_util.h>
 
 #include "HALUtil.h"
@@ -227,13 +228,11 @@ Java_edu_wpi_first_hal_HAL_getJoystickAxes
 
   jsize javaSize = env->GetArrayLength(axesArray);
   if (axes.count > javaSize) {
-    wpi::SmallString<128> errStr;
-    wpi::raw_svector_ostream oss{errStr};
-    oss << "Native array size larger then passed in java array size "
-        << "Native Size: " << static_cast<int>(axes.count)
-        << " Java Size: " << static_cast<int>(javaSize);
-
-    ThrowIllegalArgumentException(env, errStr.str());
+    ThrowIllegalArgumentException(
+        env,
+        fmt::format("Native array size larger then passed in java array "
+                    "size\nNative Size: {} Java Size: {}",
+                    static_cast<int>(axes.count), static_cast<int>(javaSize)));
     return 0;
   }
 
@@ -256,13 +255,11 @@ Java_edu_wpi_first_hal_HAL_getJoystickPOVs
 
   jsize javaSize = env->GetArrayLength(povsArray);
   if (povs.count > javaSize) {
-    wpi::SmallString<128> errStr;
-    wpi::raw_svector_ostream oss{errStr};
-    oss << "Native array size larger then passed in java array size "
-        << "Native Size: " << static_cast<int>(povs.count)
-        << " Java Size: " << static_cast<int>(javaSize);
-
-    ThrowIllegalArgumentException(env, errStr.str());
+    ThrowIllegalArgumentException(
+        env,
+        fmt::format("Native array size larger then passed in java array "
+                    "size\nNative Size: {} Java Size: {}",
+                    static_cast<int>(povs.count), static_cast<int>(javaSize)));
     return 0;
   }
 
diff --git a/hal/src/main/native/cpp/jni/HALUtil.cpp b/hal/src/main/native/cpp/jni/HALUtil.cpp
index 9894942f12..1cf7cbb3d0 100644
--- a/hal/src/main/native/cpp/jni/HALUtil.cpp
+++ b/hal/src/main/native/cpp/jni/HALUtil.cpp
@@ -12,9 +12,8 @@
 #include <cstring>
 #include <string>
 
-#include <wpi/SmallString.h>
+#include <fmt/format.h>
 #include <wpi/jni_util.h>
-#include <wpi/raw_ostream.h>
 
 #include "edu_wpi_first_hal_HALUtil.h"
 #include "hal/CAN.h"
@@ -72,7 +71,7 @@ static const JExceptionInit exceptions[] = {
 
 namespace hal {
 
-void ThrowUncleanStatusException(JNIEnv* env, wpi::StringRef msg,
+void ThrowUncleanStatusException(JNIEnv* env, std::string_view msg,
                                  int32_t status) {
   static jmethodID func =
       env->GetMethodID(uncleanStatusExCls, "<init>", "(ILjava/lang/String;)V");
@@ -85,20 +84,14 @@ void ThrowUncleanStatusException(JNIEnv* env, wpi::StringRef msg,
 
 void ThrowAllocationException(JNIEnv* env, const char* lastError,
                               int32_t status) {
-  wpi::SmallString<1024> buf;
-  wpi::raw_svector_ostream oss(buf);
-
-  oss << "Code: " << status << '\n' << lastError;
-
-  allocationExCls.Throw(env, buf.c_str());
+  allocationExCls.Throw(env,
+                        fmt::format("Code: {}\n{}", status, lastError).c_str());
 }
 
 void ThrowHalHandleException(JNIEnv* env, int32_t status) {
   const char* message = HAL_GetLastError(&status);
-  wpi::SmallString<1024> buf;
-  wpi::raw_svector_ostream oss(buf);
-  oss << " Code: " << status << ". " << message;
-  halHandleExCls.Throw(env, buf.c_str());
+  halHandleExCls.Throw(env,
+                       fmt::format(" Code: {}. {}", status, message).c_str());
 }
 
 void ReportError(JNIEnv* env, int32_t status, bool doThrow) {
@@ -111,16 +104,14 @@ void ReportError(JNIEnv* env, int32_t status, bool doThrow) {
     return;
   }
   if (doThrow && status < 0) {
-    wpi::SmallString<1024> buf;
-    wpi::raw_svector_ostream oss(buf);
-    oss << " Code: " << status << ". " << message;
-    ThrowUncleanStatusException(env, buf.c_str(), status);
+    ThrowUncleanStatusException(
+        env, fmt::format(" Code: {}. {}", status, message).c_str(), status);
   } else {
     std::string func;
     auto stack = GetJavaStackTrace(env, &func, "edu.wpi.first");
     // Make a copy of message for safety, calling back into the HAL might
     // invalidate the string.
-    wpi::SmallString<256> lastMessage{wpi::StringRef{message}};
+    std::string lastMessage{message};
     HAL_SendError(1, status, 0, lastMessage.c_str(), func.c_str(),
                   stack.c_str(), 1);
   }
@@ -141,10 +132,8 @@ void ThrowError(JNIEnv* env, int32_t status, int32_t minRange, int32_t maxRange,
     ThrowHalHandleException(env, status);
     return;
   }
-  wpi::SmallString<1024> buf;
-  wpi::raw_svector_ostream oss(buf);
-  oss << " Code: " << status << ". " << lastError;
-  ThrowUncleanStatusException(env, buf.c_str(), status);
+  ThrowUncleanStatusException(
+      env, fmt::format(" Code: {}. {}", status, lastError).c_str(), status);
 }
 
 void ReportCANError(JNIEnv* env, int32_t status, int message_id) {
@@ -181,10 +170,8 @@ void ReportCANError(JNIEnv* env, int32_t status, int message_id) {
     }
     case HAL_ERR_CANSessionMux_NotAllowed:
     case kRIOStatusFeatureNotSupported: {
-      wpi::SmallString<100> buf;
-      wpi::raw_svector_ostream oss(buf);
-      oss << "MessageID = " << message_id;
-      canMessageNotAllowedExCls.Throw(env, buf.c_str());
+      canMessageNotAllowedExCls.Throw(
+          env, fmt::format("MessageID = {}", message_id).c_str());
       break;
     }
     case HAL_ERR_CANSessionMux_NotInitialized:
@@ -200,16 +187,14 @@ void ReportCANError(JNIEnv* env, int32_t status, int message_id) {
       break;
     }
     default: {
-      wpi::SmallString<100> buf;
-      wpi::raw_svector_ostream oss(buf);
-      oss << "Fatal status code detected: " << status;
-      uncleanStatusExCls.Throw(env, buf.c_str());
+      uncleanStatusExCls.Throw(
+          env, fmt::format("Fatal status code detected: {}", status).c_str());
       break;
     }
   }
 }
 
-void ThrowIllegalArgumentException(JNIEnv* env, wpi::StringRef msg) {
+void ThrowIllegalArgumentException(JNIEnv* env, std::string_view msg) {
   illegalArgExCls.Throw(env, msg);
 }
 
@@ -266,9 +251,9 @@ void SetMatchInfoObject(JNIEnv* env, jobject matchStatus,
 
   env->CallVoidMethod(
       matchStatus, func, MakeJString(env, matchInfo.eventName),
-      MakeJString(env, wpi::StringRef{reinterpret_cast<const char*>(
-                                          matchInfo.gameSpecificMessage),
-                                      matchInfo.gameSpecificMessageSize}),
+      MakeJString(env,
+                  {reinterpret_cast<const char*>(matchInfo.gameSpecificMessage),
+                   matchInfo.gameSpecificMessageSize}),
       static_cast<jint>(matchInfo.matchNumber),
       static_cast<jint>(matchInfo.replayNumber),
       static_cast<jint>(matchInfo.matchType));
diff --git a/hal/src/main/native/cpp/jni/HALUtil.h b/hal/src/main/native/cpp/jni/HALUtil.h
index c56c36d5d1..56faa88f1c 100644
--- a/hal/src/main/native/cpp/jni/HALUtil.h
+++ b/hal/src/main/native/cpp/jni/HALUtil.h
@@ -8,7 +8,7 @@
 #include <jni.h>
 #include <stdint.h>
 
-#include <wpi/StringRef.h>
+#include <string_view>
 
 struct HAL_MatchInfo;
 struct HAL_Value;
@@ -51,7 +51,7 @@ inline bool CheckCANStatus(JNIEnv* env, int32_t status, int32_t message_id) {
   return status == 0;
 }
 
-void ThrowIllegalArgumentException(JNIEnv* env, wpi::StringRef msg);
+void ThrowIllegalArgumentException(JNIEnv* env, std::string_view msg);
 void ThrowBoundaryException(JNIEnv* env, double value, double lower,
                             double upper);
 
diff --git a/hal/src/main/native/cpp/jni/SimDeviceJNI.cpp b/hal/src/main/native/cpp/jni/SimDeviceJNI.cpp
index e036174eb4..f681e71009 100644
--- a/hal/src/main/native/cpp/jni/SimDeviceJNI.cpp
+++ b/hal/src/main/native/cpp/jni/SimDeviceJNI.cpp
@@ -96,7 +96,7 @@ Java_edu_wpi_first_hal_SimDeviceJNI_createSimValueEnum
     if (!elem) {
       return 0;
     }
-    arr.push_back(JStringRef{env, elem}.str());
+    arr.emplace_back(JStringRef{env, elem}.str());
   }
   wpi::SmallVector<const char*, 8> carr;
   for (auto&& val : arr) {
@@ -129,7 +129,7 @@ Java_edu_wpi_first_hal_SimDeviceJNI_createSimValueEnumDouble
     if (!elem) {
       return 0;
     }
-    arr.push_back(JStringRef{env, elem}.str());
+    arr.emplace_back(JStringRef{env, elem}.str());
   }
 
   wpi::SmallVector<const char*, 8> carr;
diff --git a/hal/src/main/native/cpp/jni/simulation/BufferCallbackStore.cpp b/hal/src/main/native/cpp/jni/simulation/BufferCallbackStore.cpp
index 8f4c141d2b..265b363e17 100644
--- a/hal/src/main/native/cpp/jni/simulation/BufferCallbackStore.cpp
+++ b/hal/src/main/native/cpp/jni/simulation/BufferCallbackStore.cpp
@@ -6,6 +6,8 @@
 
 #include <jni.h>
 
+#include <cstdio>
+
 #include <wpi/jni_util.h>
 
 #include "SimulatorJNI.h"
@@ -46,18 +48,18 @@ void BufferCallbackStore::performCallback(const char* name, uint8_t* buffer,
     didAttachThread = true;
     if (vm->AttachCurrentThread(reinterpret_cast<void**>(&env), nullptr) != 0) {
       // Failed to attach, log and return
-      wpi::outs() << "Failed to attach\n";
-      wpi::outs().flush();
+      std::puts("Failed to attach");
+      std::fflush(stdout);
       return;
     }
   } else if (tryGetEnv == JNI_EVERSION) {
-    wpi::outs() << "Invalid JVM Version requested\n";
-    wpi::outs().flush();
+    std::puts("Invalid JVM Version requested");
+    std::fflush(stdout);
   }
 
-  auto toCallbackArr =
-      MakeJByteArray(env, wpi::StringRef{reinterpret_cast<const char*>(buffer),
-                                         static_cast<size_t>(length)});
+  auto toCallbackArr = MakeJByteArray(
+      env, std::string_view{reinterpret_cast<const char*>(buffer),
+                            static_cast<size_t>(length)});
 
   env->CallVoidMethod(m_call, sim::GetBufferCallback(), MakeJString(env, name),
                       toCallbackArr, static_cast<jint>(length));
diff --git a/hal/src/main/native/cpp/jni/simulation/CallbackStore.cpp b/hal/src/main/native/cpp/jni/simulation/CallbackStore.cpp
index 24426957d5..46e032015d 100644
--- a/hal/src/main/native/cpp/jni/simulation/CallbackStore.cpp
+++ b/hal/src/main/native/cpp/jni/simulation/CallbackStore.cpp
@@ -6,6 +6,8 @@
 
 #include <jni.h>
 
+#include <cstdio>
+
 #include <wpi/jni_util.h>
 
 #include "SimulatorJNI.h"
@@ -45,13 +47,13 @@ void CallbackStore::performCallback(const char* name, const HAL_Value* value) {
     didAttachThread = true;
     if (vm->AttachCurrentThread(reinterpret_cast<void**>(&env), nullptr) != 0) {
       // Failed to attach, log and return
-      wpi::outs() << "Failed to attach\n";
-      wpi::outs().flush();
+      std::puts("Failed to attach");
+      std::fflush(stdout);
       return;
     }
   } else if (tryGetEnv == JNI_EVERSION) {
-    wpi::outs() << "Invalid JVM Version requested\n";
-    wpi::outs().flush();
+    std::puts("Invalid JVM Version requested");
+    std::fflush(stdout);
   }
 
   env->CallVoidMethod(m_call, sim::GetNotifyCallback(), MakeJString(env, name),
diff --git a/hal/src/main/native/cpp/jni/simulation/ConstBufferCallbackStore.cpp b/hal/src/main/native/cpp/jni/simulation/ConstBufferCallbackStore.cpp
index 1172c649e8..cba0a5b196 100644
--- a/hal/src/main/native/cpp/jni/simulation/ConstBufferCallbackStore.cpp
+++ b/hal/src/main/native/cpp/jni/simulation/ConstBufferCallbackStore.cpp
@@ -6,6 +6,8 @@
 
 #include <jni.h>
 
+#include <cstdio>
+
 #include <wpi/jni_util.h>
 
 #include "SimulatorJNI.h"
@@ -47,18 +49,18 @@ void ConstBufferCallbackStore::performCallback(const char* name,
     didAttachThread = true;
     if (vm->AttachCurrentThread(reinterpret_cast<void**>(&env), nullptr) != 0) {
       // Failed to attach, log and return
-      wpi::outs() << "Failed to attach\n";
-      wpi::outs().flush();
+      std::puts("Failed to attach");
+      std::fflush(stdout);
       return;
     }
   } else if (tryGetEnv == JNI_EVERSION) {
-    wpi::outs() << "Invalid JVM Version requested\n";
-    wpi::outs().flush();
+    std::puts("Invalid JVM Version requested");
+    std::fflush(stdout);
   }
 
-  auto toCallbackArr =
-      MakeJByteArray(env, wpi::StringRef{reinterpret_cast<const char*>(buffer),
-                                         static_cast<size_t>(length)});
+  auto toCallbackArr = MakeJByteArray(
+      env, std::string_view{reinterpret_cast<const char*>(buffer),
+                            static_cast<size_t>(length)});
 
   env->CallVoidMethod(m_call, sim::GetConstBufferCallback(),
                       MakeJString(env, name), toCallbackArr,
diff --git a/hal/src/main/native/cpp/jni/simulation/SimDeviceDataJNI.cpp b/hal/src/main/native/cpp/jni/simulation/SimDeviceDataJNI.cpp
index a07e8af15c..51a3f0746c 100644
--- a/hal/src/main/native/cpp/jni/simulation/SimDeviceDataJNI.cpp
+++ b/hal/src/main/native/cpp/jni/simulation/SimDeviceDataJNI.cpp
@@ -6,6 +6,7 @@
 
 #include <jni.h>
 
+#include <cstdio>
 #include <utility>
 
 #include <wpi/jni_util.h>
@@ -134,13 +135,13 @@ void DeviceCallbackStore::performCallback(const char* name,
     didAttachThread = true;
     if (vm->AttachCurrentThread(reinterpret_cast<void**>(&env), nullptr) != 0) {
       // Failed to attach, log and return
-      wpi::outs() << "Failed to attach\n";
-      wpi::outs().flush();
+      std::puts("Failed to attach");
+      std::fflush(stdout);
       return;
     }
   } else if (tryGetEnv == JNI_EVERSION) {
-    wpi::outs() << "Invalid JVM Version requested\n";
-    wpi::outs().flush();
+    std::puts("Invalid JVM Version requested");
+    std::fflush(stdout);
   }
 
   env->CallVoidMethod(m_call, simDeviceCallbackCallback, MakeJString(env, name),
@@ -168,13 +169,13 @@ void ValueCallbackStore::performCallback(const char* name,
     didAttachThread = true;
     if (vm->AttachCurrentThread(reinterpret_cast<void**>(&env), nullptr) != 0) {
       // Failed to attach, log and return
-      wpi::outs() << "Failed to attach\n";
-      wpi::outs().flush();
+      std::puts("Failed to attach");
+      std::fflush(stdout);
       return;
     }
   } else if (tryGetEnv == JNI_EVERSION) {
-    wpi::outs() << "Invalid JVM Version requested\n";
-    wpi::outs().flush();
+    std::puts("Invalid JVM Version requested");
+    std::fflush(stdout);
   }
 
   auto [value1, value2] = ToValue12(value);
diff --git a/hal/src/main/native/cpp/jni/simulation/SpiReadAutoReceiveBufferCallbackStore.cpp b/hal/src/main/native/cpp/jni/simulation/SpiReadAutoReceiveBufferCallbackStore.cpp
index 67121345cd..8d43e6fa2f 100644
--- a/hal/src/main/native/cpp/jni/simulation/SpiReadAutoReceiveBufferCallbackStore.cpp
+++ b/hal/src/main/native/cpp/jni/simulation/SpiReadAutoReceiveBufferCallbackStore.cpp
@@ -6,6 +6,8 @@
 
 #include <jni.h>
 
+#include <cstdio>
+
 #include <wpi/jni_util.h>
 
 #include "SimulatorJNI.h"
@@ -47,13 +49,13 @@ int32_t SpiReadAutoReceiveBufferCallbackStore::performCallback(
     didAttachThread = true;
     if (vm->AttachCurrentThread(reinterpret_cast<void**>(&env), nullptr) != 0) {
       // Failed to attach, log and return
-      wpi::outs() << "Failed to attach\n";
-      wpi::outs().flush();
+      std::puts("Failed to attach");
+      std::fflush(stdout);
       return -1;
     }
   } else if (tryGetEnv == JNI_EVERSION) {
-    wpi::outs() << "Invalid JVM Version requested\n";
-    wpi::outs().flush();
+    std::puts("Invalid JVM Version requested");
+    std::fflush(stdout);
   }
 
   auto toCallbackArr = MakeJIntArray(
diff --git a/hal/src/main/native/include/hal/.clang-tidy b/hal/src/main/native/include/hal/.clang-tidy
index a7388ad83d..4f4edda0f0 100644
--- a/hal/src/main/native/include/hal/.clang-tidy
+++ b/hal/src/main/native/include/hal/.clang-tidy
@@ -72,4 +72,4 @@ Checks:
 FormatStyle: file
 CheckOptions:
   - key: bugprone-dangling-handle
-    value: 'wpi::StringRef;wpi::Twine'
+    value: 'std::string_view'
diff --git a/hal/src/main/native/sim/AddressableLED.cpp b/hal/src/main/native/sim/AddressableLED.cpp
index 2ddc38271a..75a09fbb17 100644
--- a/hal/src/main/native/sim/AddressableLED.cpp
+++ b/hal/src/main/native/sim/AddressableLED.cpp
@@ -4,6 +4,8 @@
 
 #include "hal/AddressableLED.h"
 
+#include <fmt/format.h>
+
 #include "DigitalInternal.h"
 #include "HALInitializer.h"
 #include "HALInternal.h"
@@ -113,9 +115,11 @@ void HAL_SetAddressableLEDLength(HAL_AddressableLEDHandle handle,
   }
   if (length > HAL_kAddressableLEDMaxLength || length < 0) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status, "LED length must be less than or equal to " +
-                                  wpi::Twine(HAL_kAddressableLEDMaxLength) +
-                                  ". " + wpi::Twine(length) + " was requested");
+    hal::SetLastError(
+        status,
+        fmt::format(
+            "LED length must be less than or equal to {}. {} was requested",
+            HAL_kAddressableLEDMaxLength, length));
     return;
   }
   SimAddressableLEDData[led->index].length = length;
@@ -131,10 +135,11 @@ void HAL_WriteAddressableLEDData(HAL_AddressableLEDHandle handle,
   }
   if (length > SimAddressableLEDData[led->index].length) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status,
-                      "Data length must be less than or equal to " +
-                          wpi::Twine(SimAddressableLEDData[led->index].length) +
-                          ". " + wpi::Twine(length) + " was requested");
+    hal::SetLastError(
+        status,
+        fmt::format(
+            "Data length must be less than or equal to {}. {} was requested",
+            SimAddressableLEDData[led->index].length, length));
     return;
   }
   SimAddressableLEDData[led->index].SetData(data, length);
diff --git a/hal/src/main/native/sim/DriverStation.cpp b/hal/src/main/native/sim/DriverStation.cpp
index e4a491327a..d02319f93f 100644
--- a/hal/src/main/native/sim/DriverStation.cpp
+++ b/hal/src/main/native/sim/DriverStation.cpp
@@ -13,9 +13,9 @@
 #include <cstring>
 #include <string>
 
+#include <fmt/format.h>
 #include <wpi/condition_variable.h>
 #include <wpi/mutex.h>
-#include <wpi/raw_ostream.h>
 
 #include "HALInitializer.h"
 #include "hal/cpp/fpga_clock.h"
@@ -83,14 +83,16 @@ int32_t HAL_SendError(HAL_Bool isError, int32_t errorCode, HAL_Bool isLVCode,
   if (i == KEEP_MSGS || (curTime - prevMsgTime[i]) >= std::chrono::seconds(1)) {
     printMsg = true;
     if (printMsg) {
+      fmt::memory_buffer buf;
       if (location && location[0] != '\0') {
-        std::fprintf(stderr, "%s at %s: ", isError ? "Error" : "Warning",
-                     location);
+        fmt::format_to(buf, "{} at {}: ", isError ? "Error" : "Warning",
+                       location);
       }
-      std::fprintf(stderr, "%s\n", details);
+      fmt::format_to(buf, "{}\n", details);
       if (callStack && callStack[0] != '\0') {
-        std::fprintf(stderr, "%s\n", callStack);
+        fmt::format_to(buf, "{}\n", callStack);
       }
+      std::fwrite(buf.data(), buf.size(), 1, stderr);
     }
     if (i == KEEP_MSGS) {
       // replace the oldest one
@@ -114,8 +116,8 @@ int32_t HAL_SendConsoleLine(const char* line) {
   if (handler) {
     return handler(line);
   }
-  wpi::outs() << line << "\n";
-  wpi::outs().flush();
+  std::puts(line);
+  std::fflush(stdout);
   return 0;
 }
 
diff --git a/hal/src/main/native/sim/Extensions.cpp b/hal/src/main/native/sim/Extensions.cpp
index ce9dcbfbea..9131bcb809 100644
--- a/hal/src/main/native/sim/Extensions.cpp
+++ b/hal/src/main/native/sim/Extensions.cpp
@@ -4,12 +4,14 @@
 
 #include "hal/Extensions.h"
 
+#include <cstdio>
+#include <string_view>
 #include <vector>
 
-#include <wpi/SmallString.h>
-#include <wpi/StringRef.h>
+#include <fmt/format.h>
+#include <wpi/SmallVector.h>
+#include <wpi/StringExtras.h>
 #include <wpi/fs.h>
-#include <wpi/raw_ostream.h>
 #include <wpi/spinlock.h>
 
 #if defined(WIN32) || defined(_WIN32)
@@ -24,7 +26,7 @@
 #define DLOPEN(a) LoadLibraryA(a)
 #define DLSYM GetProcAddress
 #define DLCLOSE FreeLibrary
-#define DLERROR "error #" << GetLastError()
+#define DLERROR fmt::format("error #{}", GetLastError())
 #else
 #define DELIM ':'
 #define HTYPE void*
@@ -53,30 +55,26 @@ extern "C" {
 
 int HAL_LoadOneExtension(const char* library) {
   int rc = 1;  // It is expected and reasonable not to find an extra simulation
-  wpi::outs() << "HAL Extensions: Attempting to load: "
-              << fs::path{library}.stem().string() << "\n";
-  wpi::outs().flush();
+  fmt::print("HAL Extensions: Attempting to load: {}\n",
+             fs::path{library}.stem().string());
+  std::fflush(stdout);
   HTYPE handle = DLOPEN(library);
 #if !defined(WIN32) && !defined(_WIN32)
   if (!handle) {
-    wpi::SmallString<128> libraryName("lib");
-    libraryName += library;
 #if defined(__APPLE__)
-    libraryName += ".dylib";
+    auto libraryName = fmt::format("lib{}.dylib", library);
 #else
-    libraryName += ".so";
+    auto libraryName = fmt::format("lib{}.so", library);
 #endif
-    wpi::outs() << "HAL Extensions: Load failed: " << DLERROR
-                << "\nTrying modified name: "
-                << fs::path{libraryName.str()}.stem() << "\n";
-    wpi::outs().flush();
+    fmt::print("HAL Extensions: Load failed: {}\nTrying modified name: {}\n",
+               DLERROR, fs::path{libraryName}.stem().string());
+    std::fflush(stdout);
     handle = DLOPEN(libraryName.c_str());
   }
 #endif
   if (!handle) {
-    wpi::outs() << "HAL Extensions: Failed to load library: " << DLERROR
-                << '\n';
-    wpi::outs().flush();
+    fmt::print("HAL Extensions: Failed to load library: {}\n", DLERROR);
+    std::fflush(stdout);
     return rc;
   }
 
@@ -88,32 +86,30 @@ int HAL_LoadOneExtension(const char* library) {
   }
 
   if (rc != 0) {
-    wpi::outs() << "HAL Extensions: Failed to load extension\n";
-    wpi::outs().flush();
+    std::puts("HAL Extensions: Failed to load extension");
+    std::fflush(stdout);
     DLCLOSE(handle);
   } else {
-    wpi::outs() << "HAL Extensions: Successfully loaded extension\n";
-    wpi::outs().flush();
+    std::puts("HAL Extensions: Successfully loaded extension");
+    std::fflush(stdout);
   }
   return rc;
 }
 
 int HAL_LoadExtensions(void) {
   int rc = 1;
-  wpi::SmallVector<wpi::StringRef, 2> libraries;
+  wpi::SmallVector<std::string_view, 2> libraries;
   const char* e = std::getenv("HALSIM_EXTENSIONS");
   if (!e) {
     if (GetShowNotFoundMessage()) {
-      wpi::outs() << "HAL Extensions: No extensions found\n";
-      wpi::outs().flush();
+      std::puts("HAL Extensions: No extensions found");
+      std::fflush(stdout);
     }
     return rc;
   }
-  wpi::StringRef env{e};
-  env.split(libraries, DELIM, -1, false);
-  for (auto& libref : libraries) {
-    wpi::SmallString<128> library(libref);
-    rc = HAL_LoadOneExtension(library.c_str());
+  wpi::split(e, libraries, DELIM, -1, false);
+  for (auto& library : libraries) {
+    rc = HAL_LoadOneExtension(std::string(library).c_str());
     if (rc < 0) {
       break;
     }
diff --git a/hal/src/main/native/sim/HAL.cpp b/hal/src/main/native/sim/HAL.cpp
index b6f9b4379d..0df981ad2e 100644
--- a/hal/src/main/native/sim/HAL.cpp
+++ b/hal/src/main/native/sim/HAL.cpp
@@ -4,10 +4,10 @@
 
 #include "hal/HAL.h"
 
+#include <cstdio>
 #include <vector>
 
 #include <wpi/mutex.h>
-#include <wpi/raw_ostream.h>
 #include <wpi/spinlock.h>
 
 #ifdef _WIN32
@@ -351,7 +351,11 @@ HAL_Bool HAL_Initialize(int32_t timeout, int32_t mode) {
   }
 #endif  // _WIN32
 
-  wpi::outs().SetUnbuffered();
+#ifndef _WIN32
+  setlinebuf(stdin);
+  setlinebuf(stdout);
+#endif
+
   if (HAL_LoadExtensions() < 0) {
     return false;
   }
diff --git a/hal/src/main/native/sim/HALInternal.h b/hal/src/main/native/sim/HALInternal.h
index 28dcdc293a..7a7863a474 100644
--- a/hal/src/main/native/sim/HALInternal.h
+++ b/hal/src/main/native/sim/HALInternal.h
@@ -6,14 +6,14 @@
 
 #include <stdint.h>
 
-#include <wpi/Twine.h>
+#include <string_view>
 
 namespace hal {
-void SetLastError(int32_t* status, const wpi::Twine& value);
-void SetLastErrorIndexOutOfRange(int32_t* status, const wpi::Twine& message,
+void SetLastError(int32_t* status, std::string_view value);
+void SetLastErrorIndexOutOfRange(int32_t* status, std::string_view message,
                                  int32_t minimum, int32_t maximum,
                                  int32_t channel);
-void SetLastErrorPreviouslyAllocated(int32_t* status, const wpi::Twine& message,
+void SetLastErrorPreviouslyAllocated(int32_t* status, std::string_view message,
                                      int32_t channel,
-                                     const wpi::Twine& previousAllocation);
+                                     std::string_view previousAllocation);
 }  // namespace hal
diff --git a/hal/src/main/native/sim/MockHooks.cpp b/hal/src/main/native/sim/MockHooks.cpp
index e4751f7d76..4e20c6acf5 100644
--- a/hal/src/main/native/sim/MockHooks.cpp
+++ b/hal/src/main/native/sim/MockHooks.cpp
@@ -8,6 +8,7 @@
 #include <cstdio>
 #include <thread>
 
+#include <fmt/format.h>
 #include <wpi/timestamp.h>
 
 #include "MockHooksInternal.h"
@@ -83,7 +84,7 @@ void HALSIM_WaitForProgramStart(void) {
   int count = 0;
   while (!programStarted) {
     count++;
-    std::printf("Waiting for program start signal: %d\n", count);
+    fmt::print("Waiting for program start signal: {}\n", count);
     std::this_thread::sleep_for(std::chrono::milliseconds(500));
   }
 }
diff --git a/hal/src/main/native/sim/PDP.cpp b/hal/src/main/native/sim/PDP.cpp
index aa08ca0dfa..f6c6bcb380 100644
--- a/hal/src/main/native/sim/PDP.cpp
+++ b/hal/src/main/native/sim/PDP.cpp
@@ -4,6 +4,8 @@
 
 #include "hal/PDP.h"
 
+#include <fmt/format.h>
+
 #include "CANAPIInternal.h"
 #include "HALInitializer.h"
 #include "HALInternal.h"
@@ -28,7 +30,7 @@ extern "C" {
 HAL_PDPHandle HAL_InitializePDP(int32_t module, int32_t* status) {
   if (!HAL_CheckPDPModule(module)) {
     *status = PARAMETER_OUT_OF_RANGE;
-    hal::SetLastError(status, "Invalid pdp module " + wpi::Twine(module));
+    hal::SetLastError(status, fmt::format("Invalid pdp module {}", module));
     return HAL_kInvalidHandle;
   }
   hal::init::CheckInit();
diff --git a/hal/src/main/native/sim/SimDevice.cpp b/hal/src/main/native/sim/SimDevice.cpp
index 3b95555c26..b6c637cedc 100644
--- a/hal/src/main/native/sim/SimDevice.cpp
+++ b/hal/src/main/native/sim/SimDevice.cpp
@@ -4,8 +4,7 @@
 
 #include "hal/SimDevice.h"
 
-#include <wpi/SmallString.h>
-#include <wpi/raw_ostream.h>
+#include <fmt/format.h>
 
 #include "HALInitializer.h"
 #include "mockdata/SimDeviceDataInternal.h"
@@ -66,19 +65,12 @@ void HAL_ResetSimValue(HAL_SimValueHandle handle) {
 }
 
 hal::SimDevice::SimDevice(const char* name, int index) {
-  wpi::SmallString<128> fullname;
-  wpi::raw_svector_ostream os(fullname);
-  os << name << '[' << index << ']';
-
-  m_handle = HAL_CreateSimDevice(fullname.c_str());
+  m_handle = HAL_CreateSimDevice(fmt::format("{}[{}]", name, index).c_str());
 }
 
 hal::SimDevice::SimDevice(const char* name, int index, int channel) {
-  wpi::SmallString<128> fullname;
-  wpi::raw_svector_ostream os(fullname);
-  os << name << '[' << index << ',' << channel << ']';
-
-  m_handle = HAL_CreateSimDevice(fullname.c_str());
+  m_handle = HAL_CreateSimDevice(
+      fmt::format("{}[{},{}]", name, index, channel).c_str());
 }
 
 }  // extern "C"
diff --git a/hal/src/main/native/sim/mockdata/SimDeviceData.cpp b/hal/src/main/native/sim/mockdata/SimDeviceData.cpp
index df7e12f542..9c7fdbc202 100644
--- a/hal/src/main/native/sim/mockdata/SimDeviceData.cpp
+++ b/hal/src/main/native/sim/mockdata/SimDeviceData.cpp
@@ -6,6 +6,8 @@
 
 #include <algorithm>
 
+#include <wpi/StringExtras.h>
+
 #include "SimDeviceDataInternal.h"
 
 using namespace hal;
@@ -71,7 +73,7 @@ void SimDeviceData::SetDeviceEnabled(const char* prefix, bool enabled) {
 bool SimDeviceData::IsDeviceEnabled(const char* name) {
   std::scoped_lock lock(m_mutex);
   for (const auto& elem : m_prefixEnabled) {
-    if (wpi::StringRef{name}.startswith(elem.first)) {
+    if (wpi::starts_with(name, elem.first)) {
       return elem.second;
     }
   }
@@ -83,7 +85,7 @@ HAL_SimDeviceHandle SimDeviceData::CreateDevice(const char* name) {
 
   // don't create if disabled
   for (const auto& elem : m_prefixEnabled) {
-    if (wpi::StringRef{name}.startswith(elem.first)) {
+    if (wpi::starts_with(name, elem.first)) {
       if (elem.second) {
         break;  // enabled
       }
@@ -272,7 +274,7 @@ int32_t SimDeviceData::RegisterDeviceCreatedCallback(
   // initial notifications
   if (initialNotify) {
     for (auto&& device : m_devices) {
-      if (wpi::StringRef{device->name}.startswith(prefix)) {
+      if (wpi::starts_with(device->name, prefix)) {
         callback(device->name.c_str(), param, device->handle);
       }
     }
@@ -332,7 +334,7 @@ void SimDeviceData::EnumerateDevices(const char* prefix, void* param,
                                      HALSIM_SimDeviceCallback callback) {
   std::scoped_lock lock(m_mutex);
   for (auto&& device : m_devices) {
-    if (wpi::StringRef{device->name}.startswith(prefix)) {
+    if (wpi::starts_with(device->name, prefix)) {
       callback(device->name.c_str(), param, device->handle);
     }
   }
diff --git a/hal/src/main/native/sim/mockdata/SimDeviceDataInternal.h b/hal/src/main/native/sim/mockdata/SimDeviceDataInternal.h
index 18ac645a4a..deff6ed282 100644
--- a/hal/src/main/native/sim/mockdata/SimDeviceDataInternal.h
+++ b/hal/src/main/native/sim/mockdata/SimDeviceDataInternal.h
@@ -11,6 +11,7 @@
 #include <utility>
 #include <vector>
 
+#include <wpi/StringExtras.h>
 #include <wpi/StringMap.h>
 #include <wpi/UidVector.h>
 #include <wpi/spinlock.h>
@@ -118,7 +119,7 @@ class SimPrefixCallbackRegistry {
   void Invoke(const char* name, U&&... u) const {
     if (m_callbacks) {
       for (auto&& cb : *m_callbacks) {
-        if (wpi::StringRef{name}.startswith(cb.prefix)) {
+        if (wpi::starts_with(name, cb.prefix)) {
           cb.callback(name, cb.param, std::forward<U>(u)...);
         }
       }
diff --git a/ntcore/.styleguide b/ntcore/.styleguide
index 67befdb7dd..8cf3a512f0 100644
--- a/ntcore/.styleguide
+++ b/ntcore/.styleguide
@@ -27,6 +27,7 @@ includeGuardRoots {
 }
 
 includeOtherLibs {
+  ^fmt/
   ^support/
   ^wpi/
 }
diff --git a/ntcore/src/main/native/cpp/Dispatcher.cpp b/ntcore/src/main/native/cpp/Dispatcher.cpp
index 839faeb1f2..f0416f54ed 100644
--- a/ntcore/src/main/native/cpp/Dispatcher.cpp
+++ b/ntcore/src/main/native/cpp/Dispatcher.cpp
@@ -7,6 +7,7 @@
 #include <algorithm>
 #include <iterator>
 
+#include <wpi/StringExtras.h>
 #include <wpi/TCPAcceptor.h>
 #include <wpi/TCPConnector.h>
 #include <wpi/timestamp.h>
@@ -18,9 +19,9 @@
 
 using namespace nt;
 
-void Dispatcher::StartServer(const wpi::Twine& persist_filename,
+void Dispatcher::StartServer(std::string_view persist_filename,
                              const char* listen_address, unsigned int port) {
-  std::string listen_address_copy(wpi::StringRef(listen_address).trim());
+  std::string listen_address_copy(wpi::trim(listen_address));
   DispatcherBase::StartServer(
       persist_filename,
       std::unique_ptr<wpi::NetworkAcceptor>(new wpi::TCPAcceptor(
@@ -28,7 +29,7 @@ void Dispatcher::StartServer(const wpi::Twine& persist_filename,
 }
 
 void Dispatcher::SetServer(const char* server_name, unsigned int port) {
-  std::string server_name_copy(wpi::StringRef(server_name).trim());
+  std::string server_name_copy(wpi::trim(server_name));
   SetConnector([=]() -> std::unique_ptr<wpi::NetworkStream> {
     return wpi::TCPConnector::connect(server_name_copy.c_str(),
                                       static_cast<int>(port), m_logger, 1);
@@ -36,10 +37,10 @@ void Dispatcher::SetServer(const char* server_name, unsigned int port) {
 }
 
 void Dispatcher::SetServer(
-    wpi::ArrayRef<std::pair<wpi::StringRef, unsigned int>> servers) {
+    wpi::ArrayRef<std::pair<std::string_view, unsigned int>> servers) {
   wpi::SmallVector<std::pair<std::string, int>, 16> servers_copy;
   for (const auto& server : servers) {
-    servers_copy.emplace_back(std::string{server.first.trim()},
+    servers_copy.emplace_back(std::string{wpi::trim(server.first)},
                               static_cast<int>(server.second));
   }
 
@@ -53,49 +54,33 @@ void Dispatcher::SetServer(
 }
 
 void Dispatcher::SetServerTeam(unsigned int team, unsigned int port) {
-  std::pair<wpi::StringRef, unsigned int> servers[5];
+  std::pair<std::string_view, unsigned int> servers[5];
 
   // 10.te.am.2
-  wpi::SmallString<32> fixed;
-  {
-    wpi::raw_svector_ostream oss{fixed};
-    oss << "10." << static_cast<int>(team / 100) << '.'
-        << static_cast<int>(team % 100) << ".2";
-    servers[0] = std::make_pair(oss.str(), port);
-  }
+  auto fixed = fmt::format("10.{}.{}.2", static_cast<int>(team / 100),
+                           static_cast<int>(team % 100));
+  servers[0] = {fixed, port};
 
   // 172.22.11.2
-  servers[1] = std::make_pair("172.22.11.2", port);
+  servers[1] = {"172.22.11.2", port};
 
   // roboRIO-<team>-FRC.local
-  wpi::SmallString<32> mdns;
-  {
-    wpi::raw_svector_ostream oss{mdns};
-    oss << "roboRIO-" << team << "-FRC.local";
-    servers[2] = std::make_pair(oss.str(), port);
-  }
+  auto mdns = fmt::format("roboRIO-{}-FRC.local", team);
+  servers[2] = {mdns, port};
 
   // roboRIO-<team>-FRC.lan
-  wpi::SmallString<32> mdns_lan;
-  {
-    wpi::raw_svector_ostream oss{mdns_lan};
-    oss << "roboRIO-" << team << "-FRC.lan";
-    servers[3] = std::make_pair(oss.str(), port);
-  }
+  auto mdns_lan = fmt::format("roboRIO-{}-FRC.lan", team);
+  servers[3] = {mdns_lan, port};
 
   // roboRIO-<team>-FRC.frc-field.local
-  wpi::SmallString<64> field_local;
-  {
-    wpi::raw_svector_ostream oss{field_local};
-    oss << "roboRIO-" << team << "-FRC.frc-field.local";
-    servers[4] = std::make_pair(oss.str(), port);
-  }
+  auto field_local = fmt::format("roboRIO-{}-FRC.frc-field.local", team);
+  servers[4] = {field_local, port};
 
   SetServer(servers);
 }
 
 void Dispatcher::SetServerOverride(const char* server_name, unsigned int port) {
-  std::string server_name_copy(wpi::StringRef(server_name).trim());
+  std::string server_name_copy(wpi::trim(server_name));
   SetConnectorOverride([=]() -> std::unique_ptr<wpi::NetworkStream> {
     return wpi::TCPConnector::connect(server_name_copy.c_str(),
                                       static_cast<int>(port), m_logger, 1);
@@ -134,7 +119,7 @@ void DispatcherBase::StartLocal() {
 }
 
 void DispatcherBase::StartServer(
-    const wpi::Twine& persist_filename,
+    std::string_view persist_filename,
     std::unique_ptr<wpi::NetworkAcceptor> acceptor) {
   {
     std::scoped_lock lock(m_user_mutex);
@@ -144,22 +129,20 @@ void DispatcherBase::StartServer(
     m_active = true;
   }
   m_networkMode = NT_NET_MODE_SERVER | NT_NET_MODE_STARTING;
-  m_persist_filename = persist_filename.str();
+  m_persist_filename = persist_filename;
   m_server_acceptor = std::move(acceptor);
 
   // Load persistent file.  Ignore errors, but pass along warnings.
-  if (!persist_filename.isTriviallyEmpty() &&
-      (!persist_filename.isSingleStringRef() ||
-       !persist_filename.getSingleStringRef().empty())) {
+  if (!persist_filename.empty()) {
     bool first = true;
     m_storage.LoadPersistent(
         persist_filename, [&](size_t line, const char* msg) {
           if (first) {
             first = false;
-            WARNING("When reading initial persistent values from '"
-                    << persist_filename << "':");
+            WARNING("When reading initial persistent values from '{}':",
+                    persist_filename);
           }
-          WARNING(persist_filename << ":" << line << ": " << msg);
+          WARNING("{}:{}: {}", persist_filename, line, msg);
         });
   }
 
@@ -230,9 +213,9 @@ void DispatcherBase::SetUpdateRate(double interval) {
   m_update_rate = static_cast<unsigned int>(interval * 1000);
 }
 
-void DispatcherBase::SetIdentity(const wpi::Twine& name) {
+void DispatcherBase::SetIdentity(std::string_view name) {
   std::scoped_lock lock(m_user_mutex);
-  m_identity = name.str();
+  m_identity = name;
 }
 
 void DispatcherBase::Flush() {
@@ -369,7 +352,7 @@ void DispatcherBase::DispatchThreadMain() {
       }
       const char* err = m_storage.SavePersistent(m_persist_filename, true);
       if (err) {
-        WARNING("periodic persistent save: " << err);
+        WARNING("periodic persistent save: {}", err);
       }
     }
 
@@ -378,7 +361,7 @@ void DispatcherBase::DispatchThreadMain() {
       bool reconnect = false;
 
       if (++count > 10) {
-        DEBUG0("dispatch running " << m_connections.size() << " connections");
+        DEBUG0("dispatch running {} connections", m_connections.size());
         count = 0;
       }
 
@@ -441,8 +424,8 @@ void DispatcherBase::ServerThreadMain() {
       m_networkMode = NT_NET_MODE_NONE;
       return;
     }
-    DEBUG0("server: client connection from " << stream->getPeerIP() << " port "
-                                             << stream->getPeerPort());
+    DEBUG0("server: client connection from {} port {}", stream->getPeerIP(),
+           stream->getPeerPort());
 
     // add to connections list
     using namespace std::placeholders;
@@ -494,13 +477,13 @@ void DispatcherBase::ClientThreadMain() {
     }
 
     // try to connect (with timeout)
-    DEBUG0("client trying to connect");
+    DEBUG0("{}", "client trying to connect");
     auto stream = connect();
     if (!stream) {
       m_networkMode = NT_NET_MODE_CLIENT | NT_NET_MODE_FAILURE;
       continue;  // keep retrying
     }
-    DEBUG0("client connected");
+    DEBUG0("{}", "client connected");
     m_networkMode = NT_NET_MODE_CLIENT;
 
     std::unique_lock lock(m_user_mutex);
@@ -538,14 +521,14 @@ bool DispatcherBase::ClientHandshake(
   }
 
   // send client hello
-  DEBUG0("client: sending hello");
+  DEBUG0("{}", "client: sending hello");
   send_msgs(Message::ClientHello(self_id));
 
   // wait for response
   auto msg = get_msg();
   if (!msg) {
     // disconnected, retry
-    DEBUG0("client: server disconnected before first response");
+    DEBUG0("{}", "client: server disconnected before first response");
     return false;
   }
 
@@ -575,11 +558,11 @@ bool DispatcherBase::ClientHandshake(
   for (;;) {
     if (!msg) {
       // disconnected, retry
-      DEBUG0("client: server disconnected during initial entries");
+      DEBUG0("{}", "client: server disconnected during initial entries");
       return false;
     }
-    DEBUG4("received init str=" << msg->str() << " id=" << msg->id()
-                                << " seq_num=" << msg->seq_num_uid());
+    DEBUG4("received init str={} id={} seq_num={}", msg->str(), msg->id(),
+           msg->seq_num_uid());
     if (msg->Is(Message::kServerHelloDone)) {
       break;
     }
@@ -590,9 +573,10 @@ bool DispatcherBase::ClientHandshake(
     }
     if (!msg->Is(Message::kEntryAssign)) {
       // unexpected message
-      DEBUG0("client: received message ("
-             << msg->type()
-             << ") other than entry assignment during initial handshake");
+      DEBUG0(
+          "client: received message ({}) other than entry assignment during "
+          "initial handshake",
+          msg->type());
       return false;
     }
     incoming.emplace_back(std::move(msg));
@@ -613,8 +597,8 @@ bool DispatcherBase::ClientHandshake(
     send_msgs(outgoing);
   }
 
-  INFO("client: CONNECTED to server " << conn.stream().getPeerIP() << " port "
-                                      << conn.stream().getPeerPort());
+  INFO("client: CONNECTED to server {} port {}", conn.stream().getPeerIP(),
+       conn.stream().getPeerPort());
   return true;
 }
 
@@ -624,18 +608,18 @@ bool DispatcherBase::ServerHandshake(
   // Wait for the client to send us a hello.
   auto msg = get_msg();
   if (!msg) {
-    DEBUG0("server: client disconnected before sending hello");
+    DEBUG0("{}", "server: client disconnected before sending hello");
     return false;
   }
   if (!msg->Is(Message::kClientHello)) {
-    DEBUG0("server: client initial message was not client hello");
+    DEBUG0("{}", "server: client initial message was not client hello");
     return false;
   }
 
   // Check that the client requested version is not too high.
   unsigned int proto_rev = msg->id();
   if (proto_rev > 0x0300) {
-    DEBUG0("server: client requested proto > 0x0300");
+    DEBUG0("{}", "server: client requested proto > 0x0300");
     send_msgs(Message::ProtoUnsup());
     return false;
   }
@@ -645,7 +629,7 @@ bool DispatcherBase::ServerHandshake(
   }
 
   // Set the proto version to the client requested version
-  DEBUG0("server: client protocol " << proto_rev);
+  DEBUG0("server: client protocol {}", proto_rev);
   conn.set_proto_rev(proto_rev);
 
   // Send initial set of assignments
@@ -664,7 +648,7 @@ bool DispatcherBase::ServerHandshake(
   outgoing.emplace_back(Message::ServerHelloDone());
 
   // Batch transmit
-  DEBUG0("server: sending initial assignments");
+  DEBUG0("{}", "server: sending initial assignments");
   send_msgs(outgoing);
 
   // In proto rev 3.0 and later, the handshake concludes with a client hello
@@ -678,7 +662,7 @@ bool DispatcherBase::ServerHandshake(
     for (;;) {
       if (!msg) {
         // disconnected, retry
-        DEBUG0("server: disconnected waiting for initial entries");
+        DEBUG0("{}", "server: disconnected waiting for initial entries");
         return false;
       }
       if (msg->Is(Message::kClientHelloDone)) {
@@ -691,9 +675,10 @@ bool DispatcherBase::ServerHandshake(
       }
       if (!msg->Is(Message::kEntryAssign)) {
         // unexpected message
-        DEBUG0("server: received message ("
-               << msg->type()
-               << ") other than entry assignment during initial handshake");
+        DEBUG0(
+            "server: received message ({}) other than entry assignment during "
+            "initial handshake",
+            msg->type());
         return false;
       }
       incoming.push_back(msg);
@@ -705,8 +690,8 @@ bool DispatcherBase::ServerHandshake(
     }
   }
 
-  INFO("server: client CONNECTED: " << conn.stream().getPeerIP() << " port "
-                                    << conn.stream().getPeerPort());
+  INFO("server: client CONNECTED: {} port {}", conn.stream().getPeerIP(),
+       conn.stream().getPeerPort());
   return true;
 }
 
diff --git a/ntcore/src/main/native/cpp/Dispatcher.h b/ntcore/src/main/native/cpp/Dispatcher.h
index 020f737a17..c18b0b4caf 100644
--- a/ntcore/src/main/native/cpp/Dispatcher.h
+++ b/ntcore/src/main/native/cpp/Dispatcher.h
@@ -9,12 +9,11 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <thread>
 #include <utility>
 #include <vector>
 
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 #include <wpi/condition_variable.h>
 #include <wpi/mutex.h>
 
@@ -45,12 +44,12 @@ class DispatcherBase : public IDispatcher {
 
   unsigned int GetNetworkMode() const;
   void StartLocal();
-  void StartServer(const wpi::Twine& persist_filename,
+  void StartServer(std::string_view persist_filename,
                    std::unique_ptr<wpi::NetworkAcceptor> acceptor);
   void StartClient();
   void Stop();
   void SetUpdateRate(double interval);
-  void SetIdentity(const wpi::Twine& name);
+  void SetIdentity(std::string_view name);
   void Flush();
   std::vector<ConnectionInfo> GetConnections() const;
   bool IsConnected() const;
@@ -132,12 +131,12 @@ class Dispatcher : public DispatcherBase {
              wpi::Logger& logger)
       : DispatcherBase(storage, notifier, logger) {}
 
-  void StartServer(const wpi::Twine& persist_filename,
+  void StartServer(std::string_view persist_filename,
                    const char* listen_address, unsigned int port);
 
   void SetServer(const char* server_name, unsigned int port);
   void SetServer(
-      wpi::ArrayRef<std::pair<wpi::StringRef, unsigned int>> servers);
+      wpi::ArrayRef<std::pair<std::string_view, unsigned int>> servers);
   void SetServerTeam(unsigned int team, unsigned int port);
 
   void SetServerOverride(const char* server_name, unsigned int port);
diff --git a/ntcore/src/main/native/cpp/DsClient.cpp b/ntcore/src/main/native/cpp/DsClient.cpp
index 073be143fa..9ed185041c 100644
--- a/ntcore/src/main/native/cpp/DsClient.cpp
+++ b/ntcore/src/main/native/cpp/DsClient.cpp
@@ -5,6 +5,7 @@
 #include "DsClient.h"
 
 #include <wpi/SmallString.h>
+#include <wpi/StringExtras.h>
 #include <wpi/TCPConnector.h>
 #include <wpi/raw_ostream.h>
 #include <wpi/raw_socket_istream.h>
@@ -80,7 +81,7 @@ void DsClient::Thread::Main() {
       continue;
     }
 
-    DEBUG3("connected to DS");
+    DEBUG3("{}", "connected to DS");
     wpi::raw_socket_istream is(*m_stream);
 
     while (m_active && !is.has_error()) {
@@ -122,24 +123,27 @@ void DsClient::Thread::Main() {
         m_stream = nullptr;
         break;
       }
-      DEBUG3("json=" << json);
+      DEBUG3("json={}", json);
 
       // Look for "robotIP":12345, and get 12345 portion
       size_t pos = json.find("\"robotIP\"");
-      if (pos == wpi::StringRef::npos) {
+      if (pos == std::string_view::npos) {
         continue;  // could not find?
       }
       pos += 9;
       pos = json.find(':', pos);
-      if (pos == wpi::StringRef::npos) {
+      if (pos == std::string_view::npos) {
         continue;  // could not find?
       }
       size_t endpos = json.find_first_not_of("0123456789", pos + 1);
-      DEBUG3("found robotIP=" << json.slice(pos + 1, endpos));
+      DEBUG3("found robotIP={}", wpi::slice(json, pos + 1, endpos));
 
       // Parse into number
       unsigned int ip = 0;
-      if (json.slice(pos + 1, endpos).getAsInteger(10, ip)) {
+      if (auto v = wpi::parse_integer<unsigned int>(
+              wpi::slice(json, pos + 1, endpos), 10)) {
+        ip = v.value();
+      } else {
         continue;  // error
       }
 
@@ -157,12 +161,10 @@ void DsClient::Thread::Main() {
       oldip = ip;
 
       // Convert number into dotted quad
-      json.clear();
-      wpi::raw_svector_ostream os{json};
-      os << ((ip >> 24) & 0xff) << "." << ((ip >> 16) & 0xff) << "."
-         << ((ip >> 8) & 0xff) << "." << (ip & 0xff);
-      INFO("client: DS overriding server IP to " << os.str());
-      m_dispatcher.SetServerOverride(json.c_str(), port);
+      auto newip = fmt::format("{}.{}.{}.{}", (ip >> 24) & 0xff,
+                               (ip >> 16) & 0xff, (ip >> 8) & 0xff, ip & 0xff);
+      INFO("client: DS overriding server IP to {}", newip);
+      m_dispatcher.SetServerOverride(newip.c_str(), port);
     }
 
     // We disconnected from the DS, clear the server override
diff --git a/ntcore/src/main/native/cpp/EntryNotifier.cpp b/ntcore/src/main/native/cpp/EntryNotifier.cpp
index fb05cd9470..6f251a3df5 100644
--- a/ntcore/src/main/native/cpp/EntryNotifier.cpp
+++ b/ntcore/src/main/native/cpp/EntryNotifier.cpp
@@ -4,6 +4,8 @@
 
 #include "EntryNotifier.h"
 
+#include <wpi/StringExtras.h>
+
 #include "Log.h"
 
 using namespace nt;
@@ -49,8 +51,7 @@ bool impl::EntryNotifierThread::Matches(const EntryListenerData& listener,
   if (listener.entry != 0 && data.entry != listener.entry) {
     return false;
   }
-  if (listener.entry == 0 &&
-      !wpi::StringRef(data.name).startswith(listener.prefix)) {
+  if (listener.entry == 0 && !wpi::starts_with(data.name, listener.prefix)) {
     return false;
   }
 
@@ -59,7 +60,7 @@ bool impl::EntryNotifierThread::Matches(const EntryListenerData& listener,
 
 unsigned int EntryNotifier::Add(
     std::function<void(const EntryNotification& event)> callback,
-    wpi::StringRef prefix, unsigned int flags) {
+    std::string_view prefix, unsigned int flags) {
   if ((flags & NT_NOTIFY_LOCAL) != 0) {
     m_local_notifiers = true;
   }
@@ -76,7 +77,7 @@ unsigned int EntryNotifier::Add(
 }
 
 unsigned int EntryNotifier::AddPolled(unsigned int poller_uid,
-                                      wpi::StringRef prefix,
+                                      std::string_view prefix,
                                       unsigned int flags) {
   if ((flags & NT_NOTIFY_LOCAL) != 0) {
     m_local_notifiers = true;
@@ -93,7 +94,7 @@ unsigned int EntryNotifier::AddPolled(unsigned int poller_uid,
   return DoAdd(poller_uid, Handle(m_inst, local_id, Handle::kEntry), flags);
 }
 
-void EntryNotifier::NotifyEntry(unsigned int local_id, wpi::StringRef name,
+void EntryNotifier::NotifyEntry(unsigned int local_id, std::string_view name,
                                 std::shared_ptr<Value> value,
                                 unsigned int flags,
                                 unsigned int only_listener) {
@@ -102,8 +103,7 @@ void EntryNotifier::NotifyEntry(unsigned int local_id, wpi::StringRef name,
   if ((flags & NT_NOTIFY_LOCAL) != 0 && !m_local_notifiers) {
     return;
   }
-  DEBUG0("notifying '" << name << "' (local=" << local_id
-                       << "), flags=" << flags);
+  DEBUG0("notifying '{}' (local={}), flags={}", name, local_id, flags);
   Send(only_listener, 0, Handle(m_inst, local_id, Handle::kEntry).handle(),
        name, value, flags);
 }
diff --git a/ntcore/src/main/native/cpp/EntryNotifier.h b/ntcore/src/main/native/cpp/EntryNotifier.h
index bfc77f7025..087d39321d 100644
--- a/ntcore/src/main/native/cpp/EntryNotifier.h
+++ b/ntcore/src/main/native/cpp/EntryNotifier.h
@@ -8,6 +8,7 @@
 #include <atomic>
 #include <memory>
 #include <string>
+#include <string_view>
 
 #include <wpi/CallbackManager.h>
 
@@ -29,13 +30,13 @@ struct EntryListenerData
   EntryListenerData() = default;
   EntryListenerData(
       std::function<void(const EntryNotification& event)> callback_,
-      wpi::StringRef prefix_, unsigned int flags_)
+      std::string_view prefix_, unsigned int flags_)
       : CallbackListenerData(callback_), prefix(prefix_), flags(flags_) {}
   EntryListenerData(
       std::function<void(const EntryNotification& event)> callback_,
       NT_Entry entry_, unsigned int flags_)
       : CallbackListenerData(callback_), entry(entry_), flags(flags_) {}
-  EntryListenerData(unsigned int poller_uid_, wpi::StringRef prefix_,
+  EntryListenerData(unsigned int poller_uid_, std::string_view prefix_,
                     unsigned int flags_)
       : CallbackListenerData(poller_uid_), prefix(prefix_), flags(flags_) {}
   EntryListenerData(unsigned int poller_uid_, NT_Entry entry_,
@@ -85,15 +86,15 @@ class EntryNotifier
   bool local_notifiers() const override;
 
   unsigned int Add(std::function<void(const EntryNotification& event)> callback,
-                   wpi::StringRef prefix, unsigned int flags) override;
+                   std::string_view prefix, unsigned int flags) override;
   unsigned int Add(std::function<void(const EntryNotification& event)> callback,
                    unsigned int local_id, unsigned int flags) override;
-  unsigned int AddPolled(unsigned int poller_uid, wpi::StringRef prefix,
+  unsigned int AddPolled(unsigned int poller_uid, std::string_view prefix,
                          unsigned int flags) override;
   unsigned int AddPolled(unsigned int poller_uid, unsigned int local_id,
                          unsigned int flags) override;
 
-  void NotifyEntry(unsigned int local_id, wpi::StringRef name,
+  void NotifyEntry(unsigned int local_id, std::string_view name,
                    std::shared_ptr<Value> value, unsigned int flags,
                    unsigned int only_listener = UINT_MAX) override;
 
diff --git a/ntcore/src/main/native/cpp/IEntryNotifier.h b/ntcore/src/main/native/cpp/IEntryNotifier.h
index bfc6da34b9..b3f91b2efa 100644
--- a/ntcore/src/main/native/cpp/IEntryNotifier.h
+++ b/ntcore/src/main/native/cpp/IEntryNotifier.h
@@ -7,6 +7,7 @@
 
 #include <climits>
 #include <memory>
+#include <string_view>
 
 #include "ntcore_cpp.h"
 
@@ -22,16 +23,17 @@ class IEntryNotifier {
 
   virtual unsigned int Add(
       std::function<void(const EntryNotification& event)> callback,
-      wpi::StringRef prefix, unsigned int flags) = 0;
+      std::string_view prefix, unsigned int flags) = 0;
   virtual unsigned int Add(
       std::function<void(const EntryNotification& event)> callback,
       unsigned int local_id, unsigned int flags) = 0;
-  virtual unsigned int AddPolled(unsigned int poller_uid, wpi::StringRef prefix,
+  virtual unsigned int AddPolled(unsigned int poller_uid,
+                                 std::string_view prefix,
                                  unsigned int flags) = 0;
   virtual unsigned int AddPolled(unsigned int poller_uid, unsigned int local_id,
                                  unsigned int flags) = 0;
 
-  virtual void NotifyEntry(unsigned int local_id, wpi::StringRef name,
+  virtual void NotifyEntry(unsigned int local_id, std::string_view name,
                            std::shared_ptr<Value> value, unsigned int flags,
                            unsigned int only_listener = UINT_MAX) = 0;
 };
diff --git a/ntcore/src/main/native/cpp/IRpcServer.h b/ntcore/src/main/native/cpp/IRpcServer.h
index 1abce862f4..aa16084ed1 100644
--- a/ntcore/src/main/native/cpp/IRpcServer.h
+++ b/ntcore/src/main/native/cpp/IRpcServer.h
@@ -6,6 +6,7 @@
 #define NTCORE_IRPCSERVER_H_
 
 #include <memory>
+#include <string_view>
 
 #include "Message.h"
 #include "ntcore_cpp.h"
@@ -14,7 +15,7 @@ namespace nt {
 
 class IRpcServer {
  public:
-  typedef std::function<void(wpi::StringRef result)> SendResponseFunc;
+  using SendResponseFunc = std::function<void(std::string_view result)>;
 
   IRpcServer() = default;
   IRpcServer(const IRpcServer&) = delete;
@@ -24,7 +25,7 @@ class IRpcServer {
   virtual void RemoveRpc(unsigned int rpc_uid) = 0;
 
   virtual void ProcessRpc(unsigned int local_id, unsigned int call_uid,
-                          wpi::StringRef name, wpi::StringRef params,
+                          std::string_view name, std::string_view params,
                           const ConnectionInfo& conn,
                           SendResponseFunc send_response,
                           unsigned int rpc_uid) = 0;
diff --git a/ntcore/src/main/native/cpp/IStorage.h b/ntcore/src/main/native/cpp/IStorage.h
index 47b3b50b01..d547d51dff 100644
--- a/ntcore/src/main/native/cpp/IStorage.h
+++ b/ntcore/src/main/native/cpp/IStorage.h
@@ -7,10 +7,10 @@
 
 #include <functional>
 #include <memory>
+#include <string_view>
 #include <vector>
 
 #include <wpi/ArrayRef.h>
-#include <wpi/Twine.h>
 
 #include "Message.h"
 #include "ntcore_cpp.h"
@@ -50,10 +50,10 @@ class IStorage {
 
   // Filename-based save/load functions.  Used both by periodic saves and
   // accessible directly via the user API.
-  virtual const char* SavePersistent(const wpi::Twine& filename,
+  virtual const char* SavePersistent(std::string_view filename,
                                      bool periodic) const = 0;
   virtual const char* LoadPersistent(
-      const wpi::Twine& filename,
+      std::string_view filename,
       std::function<void(size_t line, const char* msg)> warn) = 0;
 };
 
diff --git a/ntcore/src/main/native/cpp/Log.h b/ntcore/src/main/native/cpp/Log.h
index 112f17190c..d3066d7414 100644
--- a/ntcore/src/main/native/cpp/Log.h
+++ b/ntcore/src/main/native/cpp/Log.h
@@ -7,17 +7,17 @@
 
 #include <wpi/Logger.h>
 
-#define LOG(level, x) WPI_LOG(m_logger, level, x)
+#define LOG(level, format, ...) WPI_LOG(m_logger, level, format, __VA_ARGS__)
 
 #undef ERROR
-#define ERROR(x) WPI_ERROR(m_logger, x)
-#define WARNING(x) WPI_WARNING(m_logger, x)
-#define INFO(x) WPI_INFO(m_logger, x)
+#define ERROR(format, ...) WPI_ERROR(m_logger, format, __VA_ARGS__)
+#define WARNING(format, ...) WPI_WARNING(m_logger, format, __VA_ARGS__)
+#define INFO(format, ...) WPI_INFO(m_logger, format, __VA_ARGS__)
 
-#define DEBUG0(x) WPI_DEBUG(m_logger, x)
-#define DEBUG1(x) WPI_DEBUG1(m_logger, x)
-#define DEBUG2(x) WPI_DEBUG2(m_logger, x)
-#define DEBUG3(x) WPI_DEBUG3(m_logger, x)
-#define DEBUG4(x) WPI_DEBUG4(m_logger, x)
+#define DEBUG0(format, ...) WPI_DEBUG(m_logger, format, __VA_ARGS__)
+#define DEBUG1(format, ...) WPI_DEBUG1(m_logger, format, __VA_ARGS__)
+#define DEBUG2(format, ...) WPI_DEBUG2(m_logger, format, __VA_ARGS__)
+#define DEBUG3(format, ...) WPI_DEBUG3(m_logger, format, __VA_ARGS__)
+#define DEBUG4(format, ...) WPI_DEBUG4(m_logger, format, __VA_ARGS__)
 
 #endif  // NTCORE_LOG_H_
diff --git a/ntcore/src/main/native/cpp/LoggerImpl.cpp b/ntcore/src/main/native/cpp/LoggerImpl.cpp
index 504b3cd1ad..28c9204ec1 100644
--- a/ntcore/src/main/native/cpp/LoggerImpl.cpp
+++ b/ntcore/src/main/native/cpp/LoggerImpl.cpp
@@ -4,35 +4,29 @@
 
 #include "LoggerImpl.h"
 
-#include <wpi/SmallString.h>
-#include <wpi/StringRef.h>
+#include <fmt/format.h>
 #include <wpi/fs.h>
-#include <wpi/raw_ostream.h>
 
 using namespace nt;
 
 static void DefaultLogger(unsigned int level, const char* file,
                           unsigned int line, const char* msg) {
-  wpi::SmallString<128> buf;
-  wpi::raw_svector_ostream oss(buf);
   if (level == 20) {
-    oss << "NT: " << msg << '\n';
-    wpi::errs() << oss.str();
+    fmt::print(stderr, "NT: {}\n", msg);
     return;
   }
 
-  wpi::StringRef levelmsg;
+  std::string_view levelmsg;
   if (level >= 50) {
-    levelmsg = "CRITICAL: ";
+    levelmsg = "CRITICAL";
   } else if (level >= 40) {
-    levelmsg = "ERROR: ";
+    levelmsg = "ERROR";
   } else if (level >= 30) {
-    levelmsg = "WARNING: ";
+    levelmsg = "WARNING";
   } else {
     return;
   }
-  oss << "NT: " << levelmsg << msg << " (" << file << ':' << line << ")\n";
-  wpi::errs() << oss.str();
+  fmt::print(stderr, "NT: {}: {} ({}:{})\n", levelmsg, msg, file, line);
 }
 
 LoggerImpl::LoggerImpl(int inst) : m_inst(inst) {}
diff --git a/ntcore/src/main/native/cpp/Message.cpp b/ntcore/src/main/native/cpp/Message.cpp
index cf42651019..61efed16c9 100644
--- a/ntcore/src/main/native/cpp/Message.cpp
+++ b/ntcore/src/main/native/cpp/Message.cpp
@@ -106,7 +106,7 @@ std::shared_ptr<Message> Message::Read(WireDecoder& decoder,
       } else {
         type = get_entry_type(msg->m_id);
       }
-      WPI_DEBUG4(decoder.logger(), "update message data type: " << type);
+      WPI_DEBUG4(decoder.logger(), "update message data type: {}", type);
       msg->m_value = decoder.ReadValue(type);
       if (!msg->m_value) {
         return nullptr;
@@ -171,7 +171,7 @@ std::shared_ptr<Message> Message::Read(WireDecoder& decoder,
       if (!decoder.Read(&params, size)) {
         return nullptr;
       }
-      msg->m_str = wpi::StringRef(params, size);
+      msg->m_str.assign(params, size);
       break;
     }
     case kRpcResponse: {
@@ -193,32 +193,32 @@ std::shared_ptr<Message> Message::Read(WireDecoder& decoder,
       if (!decoder.Read(&results, size)) {
         return nullptr;
       }
-      msg->m_str = wpi::StringRef(results, size);
+      msg->m_str.assign(results, size);
       break;
     }
     default:
       decoder.set_error("unrecognized message type");
-      WPI_INFO(decoder.logger(), "unrecognized message type: " << msg_type);
+      WPI_INFO(decoder.logger(), "unrecognized message type: {}", msg_type);
       return nullptr;
   }
   return msg;
 }
 
-std::shared_ptr<Message> Message::ClientHello(wpi::StringRef self_id) {
+std::shared_ptr<Message> Message::ClientHello(std::string_view self_id) {
   auto msg = std::make_shared<Message>(kClientHello, private_init());
   msg->m_str = self_id;
   return msg;
 }
 
 std::shared_ptr<Message> Message::ServerHello(unsigned int flags,
-                                              wpi::StringRef self_id) {
+                                              std::string_view self_id) {
   auto msg = std::make_shared<Message>(kServerHello, private_init());
   msg->m_str = self_id;
   msg->m_flags = flags;
   return msg;
 }
 
-std::shared_ptr<Message> Message::EntryAssign(wpi::StringRef name,
+std::shared_ptr<Message> Message::EntryAssign(std::string_view name,
                                               unsigned int id,
                                               unsigned int seq_num,
                                               std::shared_ptr<Value> value,
@@ -257,7 +257,7 @@ std::shared_ptr<Message> Message::EntryDelete(unsigned int id) {
 }
 
 std::shared_ptr<Message> Message::ExecuteRpc(unsigned int id, unsigned int uid,
-                                             wpi::StringRef params) {
+                                             std::string_view params) {
   auto msg = std::make_shared<Message>(kExecuteRpc, private_init());
   msg->m_str = params;
   msg->m_id = id;
@@ -266,7 +266,7 @@ std::shared_ptr<Message> Message::ExecuteRpc(unsigned int id, unsigned int uid,
 }
 
 std::shared_ptr<Message> Message::RpcResponse(unsigned int id, unsigned int uid,
-                                              wpi::StringRef result) {
+                                              std::string_view result) {
   auto msg = std::make_shared<Message>(kRpcResponse, private_init());
   msg->m_str = result;
   msg->m_id = id;
diff --git a/ntcore/src/main/native/cpp/Message.h b/ntcore/src/main/native/cpp/Message.h
index 7754bb584c..53e8aac487 100644
--- a/ntcore/src/main/native/cpp/Message.h
+++ b/ntcore/src/main/native/cpp/Message.h
@@ -8,6 +8,7 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <string_view>
 
 #include "networktables/NetworkTableValue.h"
 
@@ -46,7 +47,7 @@ class Message {
 
   // Message data accessors.  Callers are responsible for knowing what data is
   // actually provided for a particular message.
-  wpi::StringRef str() const { return m_str; }
+  std::string_view str() const { return m_str; }
   std::shared_ptr<Value> value() const { return m_value; }
   unsigned int id() const { return m_id; }
   unsigned int flags() const { return m_flags; }
@@ -75,10 +76,10 @@ class Message {
   }
 
   // Create messages with data
-  static std::shared_ptr<Message> ClientHello(wpi::StringRef self_id);
+  static std::shared_ptr<Message> ClientHello(std::string_view self_id);
   static std::shared_ptr<Message> ServerHello(unsigned int flags,
-                                              wpi::StringRef self_id);
-  static std::shared_ptr<Message> EntryAssign(wpi::StringRef name,
+                                              std::string_view self_id);
+  static std::shared_ptr<Message> EntryAssign(std::string_view name,
                                               unsigned int id,
                                               unsigned int seq_num,
                                               std::shared_ptr<Value> value,
@@ -90,9 +91,9 @@ class Message {
                                               unsigned int flags);
   static std::shared_ptr<Message> EntryDelete(unsigned int id);
   static std::shared_ptr<Message> ExecuteRpc(unsigned int id, unsigned int uid,
-                                             wpi::StringRef params);
+                                             std::string_view params);
   static std::shared_ptr<Message> RpcResponse(unsigned int id, unsigned int uid,
-                                              wpi::StringRef result);
+                                              std::string_view result);
 
   Message(const Message&) = delete;
   Message& operator=(const Message&) = delete;
diff --git a/ntcore/src/main/native/cpp/NetworkConnection.cpp b/ntcore/src/main/native/cpp/NetworkConnection.cpp
index 84c8d981e8..ffc45c5b65 100644
--- a/ntcore/src/main/native/cpp/NetworkConnection.cpp
+++ b/ntcore/src/main/native/cpp/NetworkConnection.cpp
@@ -64,7 +64,7 @@ void NetworkConnection::Start() {
 }
 
 void NetworkConnection::Stop() {
-  DEBUG2("NetworkConnection stopping (" << this << ")");
+  DEBUG2("NetworkConnection stopping ({})", fmt::ptr(this));
   set_state(kDead);
   m_active = false;
   // closing the stream so the read thread terminates
@@ -103,7 +103,7 @@ void NetworkConnection::Stop() {
 }
 
 ConnectionInfo NetworkConnection::info() const {
-  return ConnectionInfo{remote_id(), m_stream->getPeerIP(),
+  return ConnectionInfo{remote_id(), std::string{m_stream->getPeerIP()},
                         static_cast<unsigned int>(m_stream->getPeerPort()),
                         m_last_update, m_proto_rev};
 }
@@ -142,7 +142,7 @@ std::string NetworkConnection::remote_id() const {
   return m_remote_id;
 }
 
-void NetworkConnection::set_remote_id(wpi::StringRef remote_id) {
+void NetworkConnection::set_remote_id(std::string_view remote_id) {
   std::scoped_lock lock(m_remote_id_mutex);
   m_remote_id = remote_id;
 }
@@ -158,7 +158,7 @@ void NetworkConnection::ReadThreadMain() {
             decoder.set_proto_rev(m_proto_rev);
             auto msg = Message::Read(decoder, m_get_entry_type);
             if (!msg && decoder.error()) {
-              DEBUG0("error reading in handshake: " << decoder.error());
+              DEBUG0("error reading in handshake: {}", decoder.error());
             }
             return msg;
           },
@@ -180,7 +180,7 @@ void NetworkConnection::ReadThreadMain() {
     auto msg = Message::Read(decoder, m_get_entry_type);
     if (!msg) {
       if (decoder.error()) {
-        INFO("read error: " << decoder.error());
+        INFO("read error: {}", decoder.error());
       }
       // terminate connection on bad message
       if (m_stream) {
@@ -188,13 +188,12 @@ void NetworkConnection::ReadThreadMain() {
       }
       break;
     }
-    DEBUG3("received type=" << msg->type() << " with str=" << msg->str()
-                            << " id=" << msg->id()
-                            << " seq_num=" << msg->seq_num_uid());
+    DEBUG3("received type={} with str={} id={} seq_num={}", msg->type(),
+           msg->str(), msg->id(), msg->seq_num_uid());
     m_last_update = Now();
     m_process_incoming(std::move(msg), this);
   }
-  DEBUG2("read thread died (" << this << ")");
+  DEBUG2("read thread died ({})", fmt::ptr(this));
   set_state(kDead);
   m_active = false;
   m_outgoing.push(Outgoing());  // also kill write thread
@@ -213,18 +212,17 @@ void NetworkConnection::WriteThreadMain() {
 
   while (m_active) {
     auto msgs = m_outgoing.pop();
-    DEBUG4("write thread woke up");
+    DEBUG4("{}", "write thread woke up");
     if (msgs.empty()) {
       continue;
     }
     encoder.set_proto_rev(m_proto_rev);
     encoder.Reset();
-    DEBUG3("sending " << msgs.size() << " messages");
+    DEBUG3("sending {} messages", msgs.size());
     for (auto& msg : msgs) {
       if (msg) {
-        DEBUG3("sending type=" << msg->type() << " with str=" << msg->str()
-                               << " id=" << msg->id()
-                               << " seq_num=" << msg->seq_num_uid());
+        DEBUG3("sending type={} with str={} id={} seq_num={}", msg->type(),
+               msg->str(), msg->id(), msg->seq_num_uid());
         msg->Write(encoder);
       }
     }
@@ -238,9 +236,9 @@ void NetworkConnection::WriteThreadMain() {
     if (m_stream->send(encoder.data(), encoder.size(), &err) == 0) {
       break;
     }
-    DEBUG4("sent " << encoder.size() << " bytes");
+    DEBUG4("sent {} bytes", encoder.size());
   }
-  DEBUG2("write thread died (" << this << ")");
+  DEBUG2("write thread died ({})", fmt::ptr(this));
   set_state(kDead);
   m_active = false;
   if (m_stream) {
diff --git a/ntcore/src/main/native/cpp/NetworkConnection.h b/ntcore/src/main/native/cpp/NetworkConnection.h
index 69015054c0..412b91702f 100644
--- a/ntcore/src/main/native/cpp/NetworkConnection.h
+++ b/ntcore/src/main/native/cpp/NetworkConnection.h
@@ -11,6 +11,7 @@
 #include <chrono>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <thread>
 #include <utility>
 #include <vector>
@@ -76,7 +77,7 @@ class NetworkConnection : public INetworkConnection {
   void set_state(State state) final;
 
   std::string remote_id() const;
-  void set_remote_id(wpi::StringRef remote_id);
+  void set_remote_id(std::string_view remote_id);
 
   uint64_t last_update() const { return m_last_update; }
 
diff --git a/ntcore/src/main/native/cpp/RpcServer.cpp b/ntcore/src/main/native/cpp/RpcServer.cpp
index 88a53b796d..b4bf96a006 100644
--- a/ntcore/src/main/native/cpp/RpcServer.cpp
+++ b/ntcore/src/main/native/cpp/RpcServer.cpp
@@ -27,7 +27,7 @@ void RpcServer::RemoveRpc(unsigned int rpc_uid) {
 }
 
 void RpcServer::ProcessRpc(unsigned int local_id, unsigned int call_uid,
-                           wpi::StringRef name, wpi::StringRef params,
+                           std::string_view name, std::string_view params,
                            const ConnectionInfo& conn,
                            SendResponseFunc send_response,
                            unsigned int rpc_uid) {
@@ -37,11 +37,12 @@ void RpcServer::ProcessRpc(unsigned int local_id, unsigned int call_uid,
 }
 
 bool RpcServer::PostRpcResponse(unsigned int local_id, unsigned int call_uid,
-                                wpi::StringRef result) {
+                                std::string_view result) {
   auto thr = GetThread();
   auto i = thr->m_response_map.find(impl::RpcIdPair{local_id, call_uid});
   if (i == thr->m_response_map.end()) {
-    WARNING("posting RPC response to nonexistent call (or duplicate response)");
+    WARNING("{}",
+            "posting RPC response to nonexistent call (or duplicate response)");
     return false;
   }
   (i->getSecond())(result);
diff --git a/ntcore/src/main/native/cpp/RpcServer.h b/ntcore/src/main/native/cpp/RpcServer.h
index e4d1b1d63d..4b830620f4 100644
--- a/ntcore/src/main/native/cpp/RpcServer.h
+++ b/ntcore/src/main/native/cpp/RpcServer.h
@@ -22,8 +22,8 @@ namespace impl {
 typedef std::pair<unsigned int, unsigned int> RpcIdPair;
 
 struct RpcNotifierData : public RpcAnswer {
-  RpcNotifierData(NT_Entry entry_, NT_RpcCall call_, wpi::StringRef name_,
-                  wpi::StringRef params_, const ConnectionInfo& conn_,
+  RpcNotifierData(NT_Entry entry_, NT_RpcCall call_, std::string_view name_,
+                  std::string_view params_, const ConnectionInfo& conn_,
                   IRpcServer::SendResponseFunc send_response_)
       : RpcAnswer{entry_, call_, name_, params_, conn_},
         send_response{std::move(send_response_)} {}
@@ -55,7 +55,7 @@ class RpcServerThread
 
   void DoCallback(std::function<void(const RpcAnswer& call)> callback,
                   const RpcNotifierData& data) {
-    DEBUG4("rpc calling " << data.name);
+    DEBUG4("rpc calling {}", data.name);
     unsigned int local_id = Handle{data.entry}.GetIndex();
     unsigned int call_uid = Handle{data.call}.GetIndex();
     RpcIdPair lookup_uid{local_id, call_uid};
@@ -94,12 +94,12 @@ class RpcServer
   void RemoveRpc(unsigned int rpc_uid) override;
 
   void ProcessRpc(unsigned int local_id, unsigned int call_uid,
-                  wpi::StringRef name, wpi::StringRef params,
+                  std::string_view name, std::string_view params,
                   const ConnectionInfo& conn, SendResponseFunc send_response,
                   unsigned int rpc_uid) override;
 
   bool PostRpcResponse(unsigned int local_id, unsigned int call_uid,
-                       wpi::StringRef result);
+                       std::string_view result);
 
  private:
   int m_inst;
diff --git a/ntcore/src/main/native/cpp/Storage.cpp b/ntcore/src/main/native/cpp/Storage.cpp
index f666976053..9e8bd83c06 100644
--- a/ntcore/src/main/native/cpp/Storage.cpp
+++ b/ntcore/src/main/native/cpp/Storage.cpp
@@ -4,6 +4,7 @@
 
 #include "Storage.h"
 
+#include <wpi/StringExtras.h>
 #include <wpi/timestamp.h>
 
 #include "Handle.h"
@@ -91,7 +92,7 @@ void Storage::ProcessIncomingEntryAssign(std::shared_ptr<Message> msg,
                                          INetworkConnection* conn) {
   std::unique_lock lock(m_mutex);
   unsigned int id = msg->id();
-  wpi::StringRef name = msg->str();
+  std::string_view name = msg->str();
   Entry* entry;
   bool may_need_update = false;
   SequenceNumber seq_num(msg->seq_num_uid());
@@ -115,7 +116,7 @@ void Storage::ProcessIncomingEntryAssign(std::shared_ptr<Message> msg,
       // ignore arbitrary entry assignments
       // this can happen due to e.g. assignment to deleted entry
       lock.unlock();
-      DEBUG0("server: received assignment to unknown entry");
+      DEBUG0("{}", "server: received assignment to unknown entry");
       return;
     }
     entry = m_idmap[id];
@@ -123,7 +124,7 @@ void Storage::ProcessIncomingEntryAssign(std::shared_ptr<Message> msg,
     // clients simply accept new assignments
     if (id == 0xffff) {
       lock.unlock();
-      DEBUG0("client: received entry assignment request?");
+      DEBUG0("{}", "client: received entry assignment request?");
       return;
     }
     if (id >= m_idmap.size()) {
@@ -178,7 +179,7 @@ void Storage::ProcessIncomingEntryAssign(std::shared_ptr<Message> msg,
   // sanity check: name should match id
   if (msg->str() != entry->name) {
     lock.unlock();
-    DEBUG0("entry assignment for same id with different name?");
+    DEBUG0("{}", "entry assignment for same id with different name?");
     return;
   }
 
@@ -228,7 +229,7 @@ void Storage::ProcessIncomingEntryUpdate(std::shared_ptr<Message> msg,
     // ignore arbitrary entry updates;
     // this can happen due to deleted entries
     lock.unlock();
-    DEBUG0("received update to unknown entry");
+    DEBUG0("{}", "received update to unknown entry");
     return;
   }
   Entry* entry = m_idmap[id];
@@ -269,7 +270,7 @@ void Storage::ProcessIncomingFlagsUpdate(std::shared_ptr<Message> msg,
     // ignore arbitrary entry updates;
     // this can happen due to deleted entries
     lock.unlock();
-    DEBUG0("received flags update to unknown entry");
+    DEBUG0("{}", "received flags update to unknown entry");
     return;
   }
 
@@ -293,7 +294,7 @@ void Storage::ProcessIncomingEntryDelete(std::shared_ptr<Message> msg,
     // ignore arbitrary entry updates;
     // this can happen due to deleted entries
     lock.unlock();
-    DEBUG0("received delete to unknown entry");
+    DEBUG0("{}", "received delete to unknown entry");
     return;
   }
 
@@ -336,13 +337,13 @@ void Storage::ProcessIncomingExecuteRpc(
     // ignore call to non-existent RPC
     // this can happen due to deleted entries
     lock.unlock();
-    DEBUG0("received RPC call to unknown entry");
+    DEBUG0("{}", "received RPC call to unknown entry");
     return;
   }
   Entry* entry = m_idmap[id];
   if (!entry->value || !entry->value->IsRpc()) {
     lock.unlock();
-    DEBUG0("received RPC call to non-RPC entry");
+    DEBUG0("{}", "received RPC call to non-RPC entry");
     return;
   }
   ConnectionInfo conn_info;
@@ -359,7 +360,7 @@ void Storage::ProcessIncomingExecuteRpc(
   unsigned int call_uid = msg->seq_num_uid();
   m_rpc_server.ProcessRpc(
       entry->local_id, call_uid, entry->name, msg->str(), conn_info,
-      [=](wpi::StringRef result) {
+      [=](std::string_view result) {
         auto c = conn_weak.lock();
         if (c) {
           c->QueueOutgoing(Message::RpcResponse(id, call_uid, result));
@@ -379,17 +380,17 @@ void Storage::ProcessIncomingRpcResponse(std::shared_ptr<Message> msg,
     // ignore response to non-existent RPC
     // this can happen due to deleted entries
     lock.unlock();
-    DEBUG0("received rpc response to unknown entry");
+    DEBUG0("{}", "received rpc response to unknown entry");
     return;
   }
   Entry* entry = m_idmap[id];
   if (!entry->value || !entry->value->IsRpc()) {
     lock.unlock();
-    DEBUG0("received RPC response to non-RPC entry");
+    DEBUG0("{}", "received RPC response to non-RPC entry");
     return;
   }
-  m_rpc_results.insert(std::make_pair(
-      RpcIdPair{entry->local_id, msg->seq_num_uid()}, msg->str()));
+  m_rpc_results.insert({RpcIdPair{entry->local_id, msg->seq_num_uid()},
+                        std::string{msg->str()}});
   m_rpc_results_cond.notify_all();
 }
 
@@ -431,18 +432,18 @@ void Storage::ApplyInitialAssignments(
   // apply assignments
   for (auto& msg : msgs) {
     if (!msg->Is(Message::kEntryAssign)) {
-      DEBUG0("client: received non-entry assignment request?");
+      DEBUG0("{}", "client: received non-entry assignment request?");
       continue;
     }
 
     unsigned int id = msg->id();
     if (id == 0xffff) {
-      DEBUG0("client: received entry assignment request?");
+      DEBUG0("{}", "client: received entry assignment request?");
       continue;
     }
 
     SequenceNumber seq_num(msg->seq_num_uid());
-    wpi::StringRef name = msg->str();
+    std::string_view name = msg->str();
 
     Entry* entry = GetOrNew(name);
     entry->seq_num = seq_num;
@@ -509,7 +510,7 @@ void Storage::ApplyInitialAssignments(
   }
 }
 
-std::shared_ptr<Value> Storage::GetEntryValue(wpi::StringRef name) const {
+std::shared_ptr<Value> Storage::GetEntryValue(std::string_view name) const {
   std::scoped_lock lock(m_mutex);
   auto i = m_entries.find(name);
   if (i == m_entries.end()) {
@@ -526,7 +527,7 @@ std::shared_ptr<Value> Storage::GetEntryValue(unsigned int local_id) const {
   return m_localmap[local_id]->value;
 }
 
-bool Storage::SetDefaultEntryValue(wpi::StringRef name,
+bool Storage::SetDefaultEntryValue(std::string_view name,
                                    std::shared_ptr<Value> value) {
   if (name.empty()) {
     return false;
@@ -566,7 +567,8 @@ bool Storage::SetDefaultEntryValue(unsigned int local_id,
   return true;
 }
 
-bool Storage::SetEntryValue(wpi::StringRef name, std::shared_ptr<Value> value) {
+bool Storage::SetEntryValue(std::string_view name,
+                            std::shared_ptr<Value> value) {
   if (name.empty()) {
     return true;
   }
@@ -664,7 +666,7 @@ void Storage::SetEntryValueImpl(Entry* entry, std::shared_ptr<Value> value,
   }
 }
 
-void Storage::SetEntryTypeValue(wpi::StringRef name,
+void Storage::SetEntryTypeValue(std::string_view name,
                                 std::shared_ptr<Value> value) {
   if (name.empty()) {
     return;
@@ -695,7 +697,7 @@ void Storage::SetEntryTypeValue(unsigned int local_id,
   SetEntryValueImpl(entry, value, lock, true);
 }
 
-void Storage::SetEntryFlags(wpi::StringRef name, unsigned int flags) {
+void Storage::SetEntryFlags(std::string_view name, unsigned int flags) {
   if (name.empty()) {
     return;
   }
@@ -747,7 +749,7 @@ void Storage::SetEntryFlagsImpl(Entry* entry, unsigned int flags,
   }
 }
 
-unsigned int Storage::GetEntryFlags(wpi::StringRef name) const {
+unsigned int Storage::GetEntryFlags(std::string_view name) const {
   std::scoped_lock lock(m_mutex);
   auto i = m_entries.find(name);
   if (i == m_entries.end()) {
@@ -764,7 +766,7 @@ unsigned int Storage::GetEntryFlags(unsigned int local_id) const {
   return m_localmap[local_id]->flags;
 }
 
-void Storage::DeleteEntry(wpi::StringRef name) {
+void Storage::DeleteEntry(std::string_view name) {
   std::unique_lock lock(m_mutex);
   auto i = m_entries.find(name);
   if (i == m_entries.end()) {
@@ -873,37 +875,32 @@ void Storage::DeleteAllEntries() {
   dispatcher->QueueOutgoing(Message::ClearEntries(), nullptr, nullptr);
 }
 
-Storage::Entry* Storage::GetOrNew(const wpi::Twine& name) {
-  wpi::SmallString<128> nameBuf;
-  wpi::StringRef nameStr = name.toStringRef(nameBuf);
-  auto& entry = m_entries[nameStr];
+Storage::Entry* Storage::GetOrNew(std::string_view name) {
+  auto& entry = m_entries[name];
   if (!entry) {
-    m_localmap.emplace_back(new Entry(nameStr));
+    m_localmap.emplace_back(new Entry(name));
     entry = m_localmap.back().get();
     entry->local_id = m_localmap.size() - 1;
   }
   return entry;
 }
 
-unsigned int Storage::GetEntry(const wpi::Twine& name) {
-  if (name.isTriviallyEmpty() ||
-      (name.isSingleStringRef() && name.getSingleStringRef().empty())) {
+unsigned int Storage::GetEntry(std::string_view name) {
+  if (name.empty()) {
     return UINT_MAX;
   }
   std::unique_lock lock(m_mutex);
   return GetOrNew(name)->local_id;
 }
 
-std::vector<unsigned int> Storage::GetEntries(const wpi::Twine& prefix,
+std::vector<unsigned int> Storage::GetEntries(std::string_view prefix,
                                               unsigned int types) {
-  wpi::SmallString<128> prefixBuf;
-  wpi::StringRef prefixStr = prefix.toStringRef(prefixBuf);
   std::scoped_lock lock(m_mutex);
   std::vector<unsigned int> ids;
   for (auto& i : m_entries) {
     Entry* entry = i.getValue();
     auto value = entry->value.get();
-    if (!value || !i.getKey().startswith(prefixStr)) {
+    if (!value || !wpi::starts_with(i.getKey(), prefix)) {
       continue;
     }
     if (types != 0 && (types & value->type()) == 0) {
@@ -970,16 +967,14 @@ uint64_t Storage::GetEntryLastChange(unsigned int local_id) const {
   return entry->value->last_change();
 }
 
-std::vector<EntryInfo> Storage::GetEntryInfo(int inst, const wpi::Twine& prefix,
+std::vector<EntryInfo> Storage::GetEntryInfo(int inst, std::string_view prefix,
                                              unsigned int types) {
-  wpi::SmallString<128> prefixBuf;
-  wpi::StringRef prefixStr = prefix.toStringRef(prefixBuf);
   std::scoped_lock lock(m_mutex);
   std::vector<EntryInfo> infos;
   for (auto& i : m_entries) {
     Entry* entry = i.getValue();
     auto value = entry->value.get();
-    if (!value || !i.getKey().startswith(prefixStr)) {
+    if (!value || !wpi::starts_with(i.getKey(), prefix)) {
       continue;
     }
     if (types != 0 && (types & value->type()) == 0) {
@@ -997,18 +992,16 @@ std::vector<EntryInfo> Storage::GetEntryInfo(int inst, const wpi::Twine& prefix,
 }
 
 unsigned int Storage::AddListener(
-    const wpi::Twine& prefix,
+    std::string_view prefix,
     std::function<void(const EntryNotification& event)> callback,
     unsigned int flags) const {
-  wpi::SmallString<128> prefixBuf;
-  wpi::StringRef prefixStr = prefix.toStringRef(prefixBuf);
   std::scoped_lock lock(m_mutex);
-  unsigned int uid = m_notifier.Add(callback, prefixStr, flags);
+  unsigned int uid = m_notifier.Add(callback, prefix, flags);
   // perform immediate notifications
   if ((flags & NT_NOTIFY_IMMEDIATE) != 0 && (flags & NT_NOTIFY_NEW) != 0) {
     for (auto& i : m_entries) {
       Entry* entry = i.getValue();
-      if (!entry->value || !i.getKey().startswith(prefixStr)) {
+      if (!entry->value || !wpi::starts_with(i.getKey(), prefix)) {
         continue;
       }
       m_notifier.NotifyEntry(entry->local_id, i.getKey(), entry->value,
@@ -1037,16 +1030,14 @@ unsigned int Storage::AddListener(
 }
 
 unsigned int Storage::AddPolledListener(unsigned int poller,
-                                        const wpi::Twine& prefix,
+                                        std::string_view prefix,
                                         unsigned int flags) const {
-  wpi::SmallString<128> prefixBuf;
-  wpi::StringRef prefixStr = prefix.toStringRef(prefixBuf);
   std::scoped_lock lock(m_mutex);
-  unsigned int uid = m_notifier.AddPolled(poller, prefixStr, flags);
+  unsigned int uid = m_notifier.AddPolled(poller, prefix, flags);
   // perform immediate notifications
   if ((flags & NT_NOTIFY_IMMEDIATE) != 0 && (flags & NT_NOTIFY_NEW) != 0) {
     for (auto& i : m_entries) {
-      if (!i.getKey().startswith(prefixStr)) {
+      if (!wpi::starts_with(i.getKey(), prefix)) {
         continue;
       }
       Entry* entry = i.getValue();
@@ -1111,11 +1102,9 @@ bool Storage::GetPersistentEntries(
 }
 
 bool Storage::GetEntries(
-    const wpi::Twine& prefix,
+    std::string_view prefix,
     std::vector<std::pair<std::string, std::shared_ptr<Value>>>* entries)
     const {
-  wpi::SmallString<128> prefixBuf;
-  wpi::StringRef prefixStr = prefix.toStringRef(prefixBuf);
   // copy values out of storage as quickly as possible so lock isn't held
   {
     std::scoped_lock lock(m_mutex);
@@ -1123,7 +1112,7 @@ bool Storage::GetEntries(
     for (auto& i : m_entries) {
       Entry* entry = i.getValue();
       // only write values with given prefix
-      if (!entry->value || !i.getKey().startswith(prefixStr)) {
+      if (!entry->value || !wpi::starts_with(i.getKey(), prefix)) {
         continue;
       }
       entries->emplace_back(i.getKey(), entry->value);
@@ -1139,7 +1128,7 @@ bool Storage::GetEntries(
   return true;
 }
 
-void Storage::CreateRpc(unsigned int local_id, wpi::StringRef def,
+void Storage::CreateRpc(unsigned int local_id, std::string_view def,
                         unsigned int rpc_uid) {
   std::unique_lock lock(m_mutex);
   if (local_id >= m_localmap.size()) {
@@ -1184,7 +1173,7 @@ void Storage::CreateRpc(unsigned int local_id, wpi::StringRef def,
   }
 }
 
-unsigned int Storage::CallRpc(unsigned int local_id, wpi::StringRef params) {
+unsigned int Storage::CallRpc(unsigned int local_id, std::string_view params) {
   std::unique_lock lock(m_mutex);
   if (local_id >= m_localmap.size()) {
     return 0;
@@ -1202,7 +1191,7 @@ unsigned int Storage::CallRpc(unsigned int local_id, wpi::StringRef params) {
   unsigned int call_uid = entry->rpc_call_uid;
 
   auto msg = Message::ExecuteRpc(entry->id, call_uid, params);
-  wpi::StringRef name{entry->name};
+  std::string_view name{entry->name};
 
   if (m_server) {
     // RPCs are unlikely to be used locally on the server, but handle it
@@ -1218,10 +1207,10 @@ unsigned int Storage::CallRpc(unsigned int local_id, wpi::StringRef params) {
     unsigned int call_uid = msg->seq_num_uid();
     m_rpc_server.ProcessRpc(
         local_id, call_uid, name, msg->str(), conn_info,
-        [=](wpi::StringRef result) {
+        [=](std::string_view result) {
           std::scoped_lock lock(m_mutex);
-          m_rpc_results.insert(
-              std::make_pair(RpcIdPair{local_id, call_uid}, result));
+          m_rpc_results.insert(std::make_pair(RpcIdPair{local_id, call_uid},
+                                              std::string{result}));
           m_rpc_results_cond.notify_all();
         },
         rpc_uid);
diff --git a/ntcore/src/main/native/cpp/Storage.h b/ntcore/src/main/native/cpp/Storage.h
index 96968b4573..3ca834cdb2 100644
--- a/ntcore/src/main/native/cpp/Storage.h
+++ b/ntcore/src/main/native/cpp/Storage.h
@@ -12,6 +12,7 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
@@ -72,35 +73,36 @@ class Storage : public IStorage {
 
   // User functions.  These are the actual implementations of the corresponding
   // user API functions in ntcore_cpp.
-  std::shared_ptr<Value> GetEntryValue(wpi::StringRef name) const;
+  std::shared_ptr<Value> GetEntryValue(std::string_view name) const;
   std::shared_ptr<Value> GetEntryValue(unsigned int local_id) const;
 
-  bool SetDefaultEntryValue(wpi::StringRef name, std::shared_ptr<Value> value);
+  bool SetDefaultEntryValue(std::string_view name,
+                            std::shared_ptr<Value> value);
   bool SetDefaultEntryValue(unsigned int local_id,
                             std::shared_ptr<Value> value);
 
-  bool SetEntryValue(wpi::StringRef name, std::shared_ptr<Value> value);
+  bool SetEntryValue(std::string_view name, std::shared_ptr<Value> value);
   bool SetEntryValue(unsigned int local_id, std::shared_ptr<Value> value);
 
-  void SetEntryTypeValue(wpi::StringRef name, std::shared_ptr<Value> value);
+  void SetEntryTypeValue(std::string_view name, std::shared_ptr<Value> value);
   void SetEntryTypeValue(unsigned int local_id, std::shared_ptr<Value> value);
 
-  void SetEntryFlags(wpi::StringRef name, unsigned int flags);
+  void SetEntryFlags(std::string_view name, unsigned int flags);
   void SetEntryFlags(unsigned int local_id, unsigned int flags);
 
-  unsigned int GetEntryFlags(wpi::StringRef name) const;
+  unsigned int GetEntryFlags(std::string_view name) const;
   unsigned int GetEntryFlags(unsigned int local_id) const;
 
-  void DeleteEntry(wpi::StringRef name);
+  void DeleteEntry(std::string_view name);
   void DeleteEntry(unsigned int local_id);
 
   void DeleteAllEntries();
 
-  std::vector<EntryInfo> GetEntryInfo(int inst, const wpi::Twine& prefix,
+  std::vector<EntryInfo> GetEntryInfo(int inst, std::string_view prefix,
                                       unsigned int types);
 
   unsigned int AddListener(
-      const wpi::Twine& prefix,
+      std::string_view prefix,
       std::function<void(const EntryNotification& event)> callback,
       unsigned int flags) const;
   unsigned int AddListener(
@@ -109,14 +111,14 @@ class Storage : public IStorage {
       unsigned int flags) const;
 
   unsigned int AddPolledListener(unsigned int poller_uid,
-                                 const wpi::Twine& prefix,
+                                 std::string_view prefix,
                                  unsigned int flags) const;
   unsigned int AddPolledListener(unsigned int poller_uid, unsigned int local_id,
                                  unsigned int flags) const;
 
   // Index-only
-  unsigned int GetEntry(const wpi::Twine& name);
-  std::vector<unsigned int> GetEntries(const wpi::Twine& prefix,
+  unsigned int GetEntry(std::string_view name);
+  std::vector<unsigned int> GetEntries(std::string_view prefix,
                                        unsigned int types);
   EntryInfo GetEntryInfo(int inst, unsigned int local_id) const;
   std::string GetEntryName(unsigned int local_id) const;
@@ -125,32 +127,32 @@ class Storage : public IStorage {
 
   // Filename-based save/load functions.  Used both by periodic saves and
   // accessible directly via the user API.
-  const char* SavePersistent(const wpi::Twine& filename,
+  const char* SavePersistent(std::string_view filename,
                              bool periodic) const override;
   const char* LoadPersistent(
-      const wpi::Twine& filename,
+      std::string_view filename,
       std::function<void(size_t line, const char* msg)> warn) override;
 
-  const char* SaveEntries(const wpi::Twine& filename,
-                          const wpi::Twine& prefix) const;
+  const char* SaveEntries(std::string_view filename,
+                          std::string_view prefix) const;
   const char* LoadEntries(
-      const wpi::Twine& filename, const wpi::Twine& prefix,
+      std::string_view filename, std::string_view prefix,
       std::function<void(size_t line, const char* msg)> warn);
 
   // Stream-based save/load functions (exposed for testing purposes).  These
   // implement the guts of the filename-based functions.
   void SavePersistent(wpi::raw_ostream& os, bool periodic) const;
-  bool LoadEntries(wpi::raw_istream& is, const wpi::Twine& prefix,
+  bool LoadEntries(wpi::raw_istream& is, std::string_view prefix,
                    bool persistent,
                    std::function<void(size_t line, const char* msg)> warn);
 
-  void SaveEntries(wpi::raw_ostream& os, const wpi::Twine& prefix) const;
+  void SaveEntries(wpi::raw_ostream& os, std::string_view prefix) const;
 
   // RPC configuration needs to come through here as RPC definitions are
   // actually special Storage value types.
-  void CreateRpc(unsigned int local_id, wpi::StringRef def,
+  void CreateRpc(unsigned int local_id, std::string_view def,
                  unsigned int rpc_uid);
-  unsigned int CallRpc(unsigned int local_id, wpi::StringRef params);
+  unsigned int CallRpc(unsigned int local_id, std::string_view params);
   bool GetRpcResult(unsigned int local_id, unsigned int call_uid,
                     std::string* result);
   bool GetRpcResult(unsigned int local_id, unsigned int call_uid,
@@ -160,7 +162,7 @@ class Storage : public IStorage {
  private:
   // Data for each table entry.
   struct Entry {
-    explicit Entry(wpi::StringRef name_) : name(name_) {}
+    explicit Entry(std::string_view name_) : name(name_) {}
     bool IsPersistent() const { return (flags & NT_PERSISTENT) != 0; }
 
     // We redundantly store the name so that it's available when accessing the
@@ -242,7 +244,7 @@ class Storage : public IStorage {
       bool periodic,
       std::vector<std::pair<std::string, std::shared_ptr<Value>>>* entries)
       const;
-  bool GetEntries(const wpi::Twine& prefix,
+  bool GetEntries(std::string_view prefix,
                   std::vector<std::pair<std::string, std::shared_ptr<Value>>>*
                       entries) const;
   void SetEntryValueImpl(Entry* entry, std::shared_ptr<Value> value,
@@ -256,7 +258,7 @@ class Storage : public IStorage {
   template <typename F>
   void DeleteAllEntriesImpl(bool local, F should_delete);
   void DeleteAllEntriesImpl(bool local);
-  Entry* GetOrNew(const wpi::Twine& name);
+  Entry* GetOrNew(std::string_view name);
 };
 
 }  // namespace nt
diff --git a/ntcore/src/main/native/cpp/Storage_load.cpp b/ntcore/src/main/native/cpp/Storage_load.cpp
index 04904aaa03..fdc80a4334 100644
--- a/ntcore/src/main/native/cpp/Storage_load.cpp
+++ b/ntcore/src/main/native/cpp/Storage_load.cpp
@@ -27,13 +27,13 @@ class LoadPersistentImpl {
   LoadPersistentImpl(wpi::raw_istream& is, WarnFunc warn)
       : m_is(is), m_warn(std::move(warn)) {}
 
-  bool Load(wpi::StringRef prefix, std::vector<Entry>* entries);
+  bool Load(std::string_view prefix, std::vector<Entry>* entries);
 
  private:
   bool ReadLine();
   bool ReadHeader();
   NT_Type ReadType();
-  wpi::StringRef ReadName(wpi::SmallVectorImpl<char>& buf);
+  std::string_view ReadName(wpi::SmallVectorImpl<char>& buf);
   std::shared_ptr<Value> ReadValue(NT_Type type);
   std::shared_ptr<Value> ReadBooleanValue();
   std::shared_ptr<Value> ReadDoubleValue();
@@ -52,7 +52,7 @@ class LoadPersistentImpl {
   wpi::raw_istream& m_is;
   WarnFunc m_warn;
 
-  wpi::StringRef m_line;
+  std::string_view m_line;
   wpi::SmallString<128> m_line_buf;
   size_t m_line_num = 0;
 
@@ -71,11 +71,11 @@ class LoadPersistentImpl {
  * Returns a pair containing the extracted token (if any) and the remaining
  * tail string.
  */
-static std::pair<wpi::StringRef, wpi::StringRef> ReadStringToken(
-    wpi::StringRef source) {
+static std::pair<std::string_view, std::string_view> ReadStringToken(
+    std::string_view source) {
   // Match opening quote
   if (source.empty() || source.front() != '"') {
-    return std::make_pair(wpi::StringRef(), source);
+    return {{}, source};
   }
 
   // Scan for ending double quote, checking for escaped as we go.
@@ -87,7 +87,7 @@ static std::pair<wpi::StringRef, wpi::StringRef> ReadStringToken(
       break;
     }
   }
-  return std::make_pair(source.slice(0, pos), source.substr(pos));
+  return {wpi::slice(source, 0, pos), source.substr(pos)};
 }
 
 static int fromxdigit(char ch) {
@@ -100,8 +100,8 @@ static int fromxdigit(char ch) {
   }
 }
 
-static wpi::StringRef UnescapeString(wpi::StringRef source,
-                                     wpi::SmallVectorImpl<char>& buf) {
+static std::string_view UnescapeString(std::string_view source,
+                                       wpi::SmallVectorImpl<char>& buf) {
   assert(source.size() >= 2 && source.front() == '"' && source.back() == '"');
   buf.clear();
   buf.reserve(source.size() - 2);
@@ -135,10 +135,10 @@ static wpi::StringRef UnescapeString(wpi::StringRef source,
         break;
     }
   }
-  return wpi::StringRef{buf.data(), buf.size()};
+  return {buf.data(), buf.size()};
 }
 
-bool LoadPersistentImpl::Load(wpi::StringRef prefix,
+bool LoadPersistentImpl::Load(std::string_view prefix,
                               std::vector<Entry>* entries) {
   if (!ReadHeader()) {
     return false;  // header
@@ -154,18 +154,19 @@ bool LoadPersistentImpl::Load(wpi::StringRef prefix,
 
     // name
     wpi::SmallString<128> buf;
-    wpi::StringRef name = ReadName(buf);
-    if (name.empty() || !name.startswith(prefix)) {
+    std::string_view name = ReadName(buf);
+    if (name.empty() || !wpi::starts_with(name, prefix)) {
       continue;
     }
 
     // =
-    m_line = m_line.ltrim(" \t");
+    m_line = wpi::ltrim(m_line, " \t");
     if (m_line.empty() || m_line.front() != '=') {
       Warn("expected = after name");
       continue;
     }
-    m_line = m_line.drop_front().ltrim(" \t");
+    m_line.remove_prefix(1);
+    m_line = wpi::ltrim(m_line, " \t");
 
     // value
     auto value = ReadValue(type);
@@ -182,7 +183,7 @@ bool LoadPersistentImpl::ReadLine() {
   // ignore blank lines and lines that start with ; or # (comments)
   while (!m_is.has_error()) {
     ++m_line_num;
-    m_line = m_is.getline(m_line_buf, INT_MAX).trim();
+    m_line = wpi::trim(m_is.getline(m_line_buf, INT_MAX));
     if (!m_line.empty() && m_line.front() != ';' && m_line.front() != '#') {
       return true;
     }
@@ -200,8 +201,8 @@ bool LoadPersistentImpl::ReadHeader() {
 }
 
 NT_Type LoadPersistentImpl::ReadType() {
-  wpi::StringRef tok;
-  std::tie(tok, m_line) = m_line.split(' ');
+  std::string_view tok;
+  std::tie(tok, m_line) = wpi::split(m_line, ' ');
   if (tok == "boolean") {
     return NT_BOOLEAN;
   } else if (tok == "double") {
@@ -211,8 +212,8 @@ NT_Type LoadPersistentImpl::ReadType() {
   } else if (tok == "raw") {
     return NT_RAW;
   } else if (tok == "array") {
-    wpi::StringRef array_tok;
-    std::tie(array_tok, m_line) = m_line.split(' ');
+    std::string_view array_tok;
+    std::tie(array_tok, m_line) = wpi::split(m_line, ' ');
     if (array_tok == "boolean") {
       return NT_BOOLEAN_ARRAY;
     } else if (array_tok == "double") {
@@ -224,16 +225,16 @@ NT_Type LoadPersistentImpl::ReadType() {
   return NT_UNASSIGNED;
 }
 
-wpi::StringRef LoadPersistentImpl::ReadName(wpi::SmallVectorImpl<char>& buf) {
-  wpi::StringRef tok;
+std::string_view LoadPersistentImpl::ReadName(wpi::SmallVectorImpl<char>& buf) {
+  std::string_view tok;
   std::tie(tok, m_line) = ReadStringToken(m_line);
   if (tok.empty()) {
     Warn("missing name");
-    return wpi::StringRef{};
+    return {};
   }
   if (tok.back() != '"') {
     Warn("unterminated name string");
-    return wpi::StringRef{};
+    return {};
   }
   return UnescapeString(tok, buf);
 }
@@ -273,7 +274,7 @@ std::shared_ptr<Value> LoadPersistentImpl::ReadBooleanValue() {
 
 std::shared_ptr<Value> LoadPersistentImpl::ReadDoubleValue() {
   // need to convert to null-terminated string for std::strtod()
-  wpi::SmallString<64> buf = m_line;
+  wpi::SmallString<64> buf{m_line};
   char* end;
   double v = std::strtod(buf.c_str(), &end);
   if (*end != '\0') {
@@ -284,7 +285,7 @@ std::shared_ptr<Value> LoadPersistentImpl::ReadDoubleValue() {
 }
 
 std::shared_ptr<Value> LoadPersistentImpl::ReadStringValue() {
-  wpi::StringRef tok;
+  std::string_view tok;
   std::tie(tok, m_line) = ReadStringToken(m_line);
   if (tok.empty()) {
     Warn("missing string value");
@@ -307,9 +308,9 @@ std::shared_ptr<Value> LoadPersistentImpl::ReadRawValue() {
 std::shared_ptr<Value> LoadPersistentImpl::ReadBooleanArrayValue() {
   m_buf_boolean_array.clear();
   while (!m_line.empty()) {
-    wpi::StringRef tok;
-    std::tie(tok, m_line) = m_line.split(',');
-    tok = tok.trim(" \t");
+    std::string_view tok;
+    std::tie(tok, m_line) = wpi::split(m_line, ',');
+    tok = wpi::trim(tok, " \t");
     if (tok == "true") {
       m_buf_boolean_array.push_back(1);
     } else if (tok == "false") {
@@ -325,11 +326,11 @@ std::shared_ptr<Value> LoadPersistentImpl::ReadBooleanArrayValue() {
 std::shared_ptr<Value> LoadPersistentImpl::ReadDoubleArrayValue() {
   m_buf_double_array.clear();
   while (!m_line.empty()) {
-    wpi::StringRef tok;
-    std::tie(tok, m_line) = m_line.split(',');
-    tok = tok.trim(" \t");
+    std::string_view tok;
+    std::tie(tok, m_line) = wpi::split(m_line, ',');
+    tok = wpi::trim(tok, " \t");
     // need to convert to null-terminated string for std::strtod()
-    wpi::SmallString<64> buf = tok;
+    wpi::SmallString<64> buf{tok};
     char* end;
     double v = std::strtod(buf.c_str(), &end);
     if (*end != '\0') {
@@ -345,7 +346,7 @@ std::shared_ptr<Value> LoadPersistentImpl::ReadDoubleArrayValue() {
 std::shared_ptr<Value> LoadPersistentImpl::ReadStringArrayValue() {
   m_buf_string_array.clear();
   while (!m_line.empty()) {
-    wpi::StringRef tok;
+    std::string_view tok;
     std::tie(tok, m_line) = ReadStringToken(m_line);
     if (tok.empty()) {
       Warn("missing string value");
@@ -357,9 +358,9 @@ std::shared_ptr<Value> LoadPersistentImpl::ReadStringArrayValue() {
     }
 
     wpi::SmallString<128> buf;
-    m_buf_string_array.push_back(UnescapeString(tok, buf));
+    m_buf_string_array.emplace_back(UnescapeString(tok, buf));
 
-    m_line = m_line.ltrim(" \t");
+    m_line = wpi::ltrim(m_line, " \t");
     if (m_line.empty()) {
       break;
     }
@@ -367,23 +368,21 @@ std::shared_ptr<Value> LoadPersistentImpl::ReadStringArrayValue() {
       Warn("expected comma between strings");
       return nullptr;
     }
-    m_line = m_line.drop_front().ltrim(" \t");
+    m_line.remove_prefix(1);
+    m_line = wpi::ltrim(m_line, " \t");
   }
 
   return Value::MakeStringArray(std::move(m_buf_string_array));
 }
 
 bool Storage::LoadEntries(
-    wpi::raw_istream& is, const wpi::Twine& prefix, bool persistent,
+    wpi::raw_istream& is, std::string_view prefix, bool persistent,
     std::function<void(size_t line, const char* msg)> warn) {
-  wpi::SmallString<128> prefixBuf;
-  wpi::StringRef prefixStr = prefix.toStringRef(prefixBuf);
-
   // entries to add
   std::vector<LoadPersistentImpl::Entry> entries;
 
   // load file
-  if (!LoadPersistentImpl(is, warn).Load(prefixStr, &entries)) {
+  if (!LoadPersistentImpl(is, warn).Load(prefix, &entries)) {
     return false;
   }
 
@@ -457,7 +456,7 @@ bool Storage::LoadEntries(
 }
 
 const char* Storage::LoadPersistent(
-    const wpi::Twine& filename,
+    std::string_view filename,
     std::function<void(size_t line, const char* msg)> warn) {
   std::error_code ec;
   wpi::raw_fd_istream is(filename, ec);
@@ -471,7 +470,7 @@ const char* Storage::LoadPersistent(
 }
 
 const char* Storage::LoadEntries(
-    const wpi::Twine& filename, const wpi::Twine& prefix,
+    std::string_view filename, std::string_view prefix,
     std::function<void(size_t line, const char* msg)> warn) {
   std::error_code ec;
   wpi::raw_fd_istream is(filename, ec);
diff --git a/ntcore/src/main/native/cpp/Storage_save.cpp b/ntcore/src/main/native/cpp/Storage_save.cpp
index 8cd6f9910c..26e0cad983 100644
--- a/ntcore/src/main/native/cpp/Storage_save.cpp
+++ b/ntcore/src/main/native/cpp/Storage_save.cpp
@@ -5,8 +5,8 @@
 #include <cctype>
 #include <string>
 
+#include <fmt/format.h>
 #include <wpi/Base64.h>
-#include <wpi/Format.h>
 #include <wpi/SmallString.h>
 #include <wpi/StringExtras.h>
 #include <wpi/fs.h>
@@ -21,17 +21,17 @@ namespace {
 
 class SavePersistentImpl {
  public:
-  typedef std::pair<std::string, std::shared_ptr<Value>> Entry;
+  using Entry = std::pair<std::string, std::shared_ptr<Value>>;
 
   explicit SavePersistentImpl(wpi::raw_ostream& os) : m_os(os) {}
 
   void Save(wpi::ArrayRef<Entry> entries);
 
  private:
-  void WriteString(wpi::StringRef str);
+  void WriteString(std::string_view str);
   void WriteHeader();
   void WriteEntries(wpi::ArrayRef<Entry> entries);
-  void WriteEntry(wpi::StringRef name, const Value& value);
+  void WriteEntry(std::string_view name, const Value& value);
   bool WriteType(NT_Type type);
   void WriteValue(const Value& value);
 
@@ -41,7 +41,7 @@ class SavePersistentImpl {
 }  // namespace
 
 /* Escapes and writes a string, including start and end double quotes */
-void SavePersistentImpl::WriteString(wpi::StringRef str) {
+void SavePersistentImpl::WriteString(std::string_view str) {
   m_os << '"';
   for (auto c : str) {
     switch (c) {
@@ -90,7 +90,7 @@ void SavePersistentImpl::WriteEntries(wpi::ArrayRef<Entry> entries) {
   }
 }
 
-void SavePersistentImpl::WriteEntry(wpi::StringRef name, const Value& value) {
+void SavePersistentImpl::WriteEntry(std::string_view name, const Value& value) {
   if (!WriteType(value.type())) {
     return;  // type
   }
@@ -135,7 +135,7 @@ void SavePersistentImpl::WriteValue(const Value& value) {
       m_os << (value.GetBoolean() ? "true" : "false");
       break;
     case NT_DOUBLE:
-      m_os << wpi::format("%g", value.GetDouble());
+      m_os << fmt::format("{:g}", value.GetDouble());
       break;
     case NT_STRING:
       WriteString(value.GetString());
@@ -162,7 +162,7 @@ void SavePersistentImpl::WriteValue(const Value& value) {
           m_os << ',';
         }
         first = false;
-        m_os << wpi::format("%g", elem);
+        m_os << fmt::format("{:g}", elem);
       }
       break;
     }
@@ -190,14 +190,11 @@ void Storage::SavePersistent(wpi::raw_ostream& os, bool periodic) const {
   SavePersistentImpl(os).Save(entries);
 }
 
-const char* Storage::SavePersistent(const wpi::Twine& filename,
+const char* Storage::SavePersistent(std::string_view filename,
                                     bool periodic) const {
-  wpi::SmallString<128> fn;
-  filename.toVector(fn);
-  wpi::SmallString<128> tmp = fn;
-  tmp += ".tmp";
-  wpi::SmallString<128> bak = fn;
-  bak += ".bak";
+  std::string fn{filename};
+  auto tmp = fmt::format("{}.tmp", filename);
+  auto bak = fmt::format("{}.bak", filename);
 
   // Get entries before creating file
   std::vector<SavePersistentImpl::Entry> entries;
@@ -214,7 +211,7 @@ const char* Storage::SavePersistent(const wpi::Twine& filename,
     err = "could not open file";
     goto done;
   }
-  DEBUG0("saving persistent file '" << filename << "'");
+  DEBUG0("saving persistent file '{}'", filename);
   SavePersistentImpl(os).Save(entries);
   os.close();
   if (os.has_error()) {
@@ -240,8 +237,7 @@ done:
   return err;
 }
 
-void Storage::SaveEntries(wpi::raw_ostream& os,
-                          const wpi::Twine& prefix) const {
+void Storage::SaveEntries(wpi::raw_ostream& os, std::string_view prefix) const {
   std::vector<SavePersistentImpl::Entry> entries;
   if (!GetEntries(prefix, &entries)) {
     return;
@@ -249,14 +245,11 @@ void Storage::SaveEntries(wpi::raw_ostream& os,
   SavePersistentImpl(os).Save(entries);
 }
 
-const char* Storage::SaveEntries(const wpi::Twine& filename,
-                                 const wpi::Twine& prefix) const {
-  wpi::SmallString<128> fn;
-  filename.toVector(fn);
-  wpi::SmallString<128> tmp = fn;
-  tmp += ".tmp";
-  wpi::SmallString<128> bak = fn;
-  bak += ".bak";
+const char* Storage::SaveEntries(std::string_view filename,
+                                 std::string_view prefix) const {
+  std::string fn{filename};
+  auto tmp = fmt::format("{}.tmp", filename);
+  auto bak = fmt::format("{}.bak", filename);
 
   // Get entries before creating file
   std::vector<SavePersistentImpl::Entry> entries;
@@ -270,7 +263,7 @@ const char* Storage::SaveEntries(const wpi::Twine& filename,
   if (ec.value() != 0) {
     return "could not open file";
   }
-  DEBUG0("saving file '" << filename << "'");
+  DEBUG0("saving file '{}'", filename);
   SavePersistentImpl(os).Save(entries);
   os.close();
   if (os.has_error()) {
diff --git a/ntcore/src/main/native/cpp/Value.cpp b/ntcore/src/main/native/cpp/Value.cpp
index ff7fcb7c0b..96af67a551 100644
--- a/ntcore/src/main/native/cpp/Value.cpp
+++ b/ntcore/src/main/native/cpp/Value.cpp
@@ -153,7 +153,7 @@ void nt::ConvertToC(const Value& in, NT_Value* out) {
   out->type = in.type();
 }
 
-void nt::ConvertToC(wpi::StringRef in, NT_String* out) {
+void nt::ConvertToC(std::string_view in, NT_String* out) {
   out->len = in.size();
   out->str = static_cast<char*>(wpi::safe_malloc(in.size() + 1));
   std::memcpy(out->str, in.data(), in.size());
@@ -184,7 +184,7 @@ std::shared_ptr<Value> nt::ConvertFromC(const NT_Value& value) {
       std::vector<std::string> v;
       v.reserve(value.data.arr_string.size);
       for (size_t i = 0; i < value.data.arr_string.size; ++i) {
-        v.push_back(ConvertFromC(value.data.arr_string.arr[i]));
+        v.emplace_back(ConvertFromC(value.data.arr_string.arr[i]));
       }
       return Value::MakeStringArray(std::move(v));
     }
diff --git a/ntcore/src/main/native/cpp/Value_internal.h b/ntcore/src/main/native/cpp/Value_internal.h
index 328f4aa87d..54850ab2c1 100644
--- a/ntcore/src/main/native/cpp/Value_internal.h
+++ b/ntcore/src/main/native/cpp/Value_internal.h
@@ -7,8 +7,7 @@
 
 #include <memory>
 #include <string>
-
-#include <wpi/StringRef.h>
+#include <string_view>
 
 #include "ntcore_c.h"
 
@@ -18,9 +17,9 @@ class Value;
 
 void ConvertToC(const Value& in, NT_Value* out);
 std::shared_ptr<Value> ConvertFromC(const NT_Value& value);
-void ConvertToC(wpi::StringRef in, NT_String* out);
-inline wpi::StringRef ConvertFromC(const NT_String& str) {
-  return wpi::StringRef(str.str, str.len);
+void ConvertToC(std::string_view in, NT_String* out);
+inline std::string_view ConvertFromC(const NT_String& str) {
+  return {str.str, str.len};
 }
 
 }  // namespace nt
diff --git a/ntcore/src/main/native/cpp/WireDecoder.cpp b/ntcore/src/main/native/cpp/WireDecoder.cpp
index e0bd01daf5..c0647dc048 100644
--- a/ntcore/src/main/native/cpp/WireDecoder.cpp
+++ b/ntcore/src/main/native/cpp/WireDecoder.cpp
@@ -242,6 +242,6 @@ bool WireDecoder::ReadString(std::string* str) {
   if (!Read(&buf, len)) {
     return false;
   }
-  *str = wpi::StringRef(buf, len);
+  str->assign(buf, len);
   return true;
 }
diff --git a/ntcore/src/main/native/cpp/WireEncoder.cpp b/ntcore/src/main/native/cpp/WireEncoder.cpp
index ca6bd332d0..b35b7808f0 100644
--- a/ntcore/src/main/native/cpp/WireEncoder.cpp
+++ b/ntcore/src/main/native/cpp/WireEncoder.cpp
@@ -198,7 +198,7 @@ void WireEncoder::WriteValue(const Value& value) {
   }
 }
 
-size_t WireEncoder::GetStringSize(wpi::StringRef str) const {
+size_t WireEncoder::GetStringSize(std::string_view str) const {
   if (m_proto_rev < 0x0300u) {
     size_t len = str.size();
     if (len > 0xffff) {
@@ -209,7 +209,7 @@ size_t WireEncoder::GetStringSize(wpi::StringRef str) const {
   return wpi::SizeUleb128(str.size()) + str.size();
 }
 
-void WireEncoder::WriteString(wpi::StringRef str) {
+void WireEncoder::WriteString(std::string_view str) {
   // length
   size_t len = str.size();
   if (m_proto_rev < 0x0300u) {
diff --git a/ntcore/src/main/native/cpp/WireEncoder.h b/ntcore/src/main/native/cpp/WireEncoder.h
index 3111f8f1ed..84edc39ebd 100644
--- a/ntcore/src/main/native/cpp/WireEncoder.h
+++ b/ntcore/src/main/native/cpp/WireEncoder.h
@@ -9,9 +9,9 @@
 
 #include <cassert>
 #include <cstddef>
+#include <string_view>
 
 #include <wpi/SmallVector.h>
-#include <wpi/StringRef.h>
 
 #include "networktables/NetworkTableValue.h"
 
@@ -49,8 +49,8 @@ class WireEncoder {
   /* Returns number of bytes written to memory buffer. */
   size_t size() const { return m_data.size(); }
 
-  wpi::StringRef ToStringRef() const {
-    return wpi::StringRef(m_data.data(), m_data.size());
+  std::string_view ToStringView() const {
+    return {m_data.data(), m_data.size()};
   }
 
   /* Writes a single byte. */
@@ -80,7 +80,7 @@ class WireEncoder {
 
   void WriteType(NT_Type type);
   void WriteValue(const Value& value);
-  void WriteString(wpi::StringRef str);
+  void WriteString(std::string_view str);
 
   /* Utility function to get the written size of a value (without actually
    * writing it).
@@ -90,7 +90,7 @@ class WireEncoder {
   /* Utility function to get the written size of a string (without actually
    * writing it).
    */
-  size_t GetStringSize(wpi::StringRef str) const;
+  size_t GetStringSize(std::string_view str) const;
 
  protected:
   /* The protocol revision.  E.g. 0x0200 for version 2.0. */
diff --git a/ntcore/src/main/native/cpp/jni/NetworkTablesJNI.cpp b/ntcore/src/main/native/cpp/jni/NetworkTablesJNI.cpp
index 75f9c713eb..b3f943c0fa 100644
--- a/ntcore/src/main/native/cpp/jni/NetworkTablesJNI.cpp
+++ b/ntcore/src/main/native/cpp/jni/NetworkTablesJNI.cpp
@@ -6,10 +6,9 @@
 
 #include <cassert>
 
+#include <fmt/format.h>
 #include <wpi/ConvertUTF.h>
-#include <wpi/SmallString.h>
 #include <wpi/jni_util.h>
-#include <wpi/raw_ostream.h>
 
 #include "edu_wpi_first_networktables_NetworkTablesJNI.h"
 #include "ntcore.h"
@@ -113,7 +112,7 @@ inline std::shared_ptr<nt::Value> FromJavaRaw(JNIEnv* env, jbyteArray jarr,
   if (!ref) {
     return nullptr;
   }
-  return nt::Value::MakeRaw(ref, time);
+  return nt::Value::MakeRaw(ref.str(), time);
 }
 
 inline std::shared_ptr<nt::Value> FromJavaRawBB(JNIEnv* env, jobject jbb,
@@ -170,7 +169,7 @@ std::shared_ptr<nt::Value> FromJavaStringArray(JNIEnv* env, jobjectArray jarr,
     if (!elem) {
       return nullptr;
     }
-    arr.push_back(JStringRef{env, elem}.str());
+    arr.emplace_back(JStringRef{env, elem}.str());
   }
   return nt::Value::MakeStringArray(std::move(arr), time);
 }
@@ -1251,7 +1250,7 @@ Java_edu_wpi_first_networktables_NetworkTablesJNI_createPolledRpc
     nullPointerEx.Throw(env, "def cannot be null");
     return;
   }
-  nt::CreatePolledRpc(entry, JByteArrayRef{env, def}, poller);
+  nt::CreatePolledRpc(entry, JByteArrayRef{env, def}.str(), poller);
 }
 
 /*
@@ -1326,7 +1325,7 @@ Java_edu_wpi_first_networktables_NetworkTablesJNI_postRpcResponse
     nullPointerEx.Throw(env, "result cannot be null");
     return false;
   }
-  return nt::PostRpcResponse(entry, call, JByteArrayRef{env, result});
+  return nt::PostRpcResponse(entry, call, JByteArrayRef{env, result}.str());
 }
 
 /*
@@ -1342,7 +1341,7 @@ Java_edu_wpi_first_networktables_NetworkTablesJNI_callRpc
     nullPointerEx.Throw(env, "params cannot be null");
     return 0;
   }
-  return nt::CallRpc(entry, JByteArrayRef{env, params});
+  return nt::CallRpc(entry, JByteArrayRef{env, params}.str());
 }
 
 /*
@@ -1549,7 +1548,7 @@ Java_edu_wpi_first_networktables_NetworkTablesJNI_startClient__I_3Ljava_lang_Str
   }
 
   std::vector<std::string> names;
-  std::vector<std::pair<wpi::StringRef, unsigned int>> servers;
+  std::vector<std::pair<std::string_view, unsigned int>> servers;
   names.reserve(len);
   servers.reserve(len);
   for (int i = 0; i < len; ++i) {
@@ -1561,7 +1560,7 @@ Java_edu_wpi_first_networktables_NetworkTablesJNI_startClient__I_3Ljava_lang_Str
     }
     names.emplace_back(JStringRef{env, elem}.str());
     servers.emplace_back(
-        std::make_pair(wpi::StringRef(names.back()), portInts[i]));
+        std::make_pair(std::string_view{names.back()}, portInts[i]));
   }
   env->ReleaseIntArrayElements(ports, portInts, JNI_ABORT);
   nt::StartClient(inst, servers);
@@ -1636,7 +1635,7 @@ Java_edu_wpi_first_networktables_NetworkTablesJNI_setServer__I_3Ljava_lang_Strin
   }
 
   std::vector<std::string> names;
-  std::vector<std::pair<wpi::StringRef, unsigned int>> servers;
+  std::vector<std::pair<std::string_view, unsigned int>> servers;
   names.reserve(len);
   servers.reserve(len);
   for (int i = 0; i < len; ++i) {
@@ -1648,7 +1647,7 @@ Java_edu_wpi_first_networktables_NetworkTablesJNI_setServer__I_3Ljava_lang_Strin
     }
     names.emplace_back(JStringRef{env, elem}.str());
     servers.emplace_back(
-        std::make_pair(wpi::StringRef(names.back()), portInts[i]));
+        std::make_pair(std::string_view{names.back()}, portInts[i]));
   }
   env->ReleaseIntArrayElements(ports, portInts, JNI_ABORT);
   nt::SetServer(inst, servers);
@@ -1781,13 +1780,10 @@ Java_edu_wpi_first_networktables_NetworkTablesJNI_loadPersistent
     return nullptr;
   }
   std::vector<std::string> warns;
-  const char* err = nt::LoadPersistent(inst, JStringRef{env, filename}.str(),
-                                       [&](size_t line, const char* msg) {
-                                         wpi::SmallString<128> warn;
-                                         wpi::raw_svector_ostream oss(warn);
-                                         oss << line << ": " << msg;
-                                         warns.emplace_back(oss.str());
-                                       });
+  const char* err = nt::LoadPersistent(
+      inst, JStringRef{env, filename}.str(), [&](size_t line, const char* msg) {
+        warns.emplace_back(fmt::format("{}: {}", line, msg));
+      });
   if (err) {
     persistentEx.Throw(env, err);
     return nullptr;
@@ -1837,14 +1833,11 @@ Java_edu_wpi_first_networktables_NetworkTablesJNI_loadEntries
     return nullptr;
   }
   std::vector<std::string> warns;
-  const char* err = nt::LoadEntries(inst, JStringRef{env, filename}.str(),
-                                    JStringRef{env, prefix}.str(),
-                                    [&](size_t line, const char* msg) {
-                                      wpi::SmallString<128> warn;
-                                      wpi::raw_svector_ostream oss(warn);
-                                      oss << line << ": " << msg;
-                                      warns.emplace_back(oss.str());
-                                    });
+  const char* err = nt::LoadEntries(
+      inst, JStringRef{env, filename}.str(), JStringRef{env, prefix}.str(),
+      [&](size_t line, const char* msg) {
+        warns.emplace_back(fmt::format("{}: {}", line, msg));
+      });
   if (err) {
     persistentEx.Throw(env, err);
     return nullptr;
diff --git a/ntcore/src/main/native/cpp/networktables/NetworkTable.cpp b/ntcore/src/main/native/cpp/networktables/NetworkTable.cpp
index d4839009ee..25bd809f02 100644
--- a/ntcore/src/main/native/cpp/networktables/NetworkTable.cpp
+++ b/ntcore/src/main/native/cpp/networktables/NetworkTable.cpp
@@ -6,61 +6,59 @@
 
 #include <algorithm>
 
+#include <fmt/core.h>
+#include <fmt/format.h>
 #include <wpi/SmallString.h>
+#include <wpi/StringExtras.h>
 #include <wpi/StringMap.h>
-#include <wpi/raw_ostream.h>
 
 #include "networktables/NetworkTableInstance.h"
 #include "ntcore.h"
 
 using namespace nt;
 
-wpi::StringRef NetworkTable::BasenameKey(wpi::StringRef key) {
+std::string_view NetworkTable::BasenameKey(std::string_view key) {
   size_t slash = key.rfind(PATH_SEPARATOR_CHAR);
-  if (slash == wpi::StringRef::npos) {
+  if (slash == std::string_view::npos) {
     return key;
   }
   return key.substr(slash + 1);
 }
 
-std::string NetworkTable::NormalizeKey(const wpi::Twine& key,
+std::string NetworkTable::NormalizeKey(std::string_view key,
                                        bool withLeadingSlash) {
   wpi::SmallString<128> buf;
-  return NormalizeKey(key, buf, withLeadingSlash);
+  return std::string{NormalizeKey(key, buf, withLeadingSlash)};
 }
 
-wpi::StringRef NetworkTable::NormalizeKey(const wpi::Twine& key,
-                                          wpi::SmallVectorImpl<char>& buf,
-                                          bool withLeadingSlash) {
+std::string_view NetworkTable::NormalizeKey(std::string_view key,
+                                            wpi::SmallVectorImpl<char>& buf,
+                                            bool withLeadingSlash) {
   buf.clear();
   if (withLeadingSlash) {
     buf.push_back(PATH_SEPARATOR_CHAR);
   }
   // for each path element, add it with a slash following
-  wpi::SmallString<128> keyBuf;
-  wpi::StringRef keyStr = key.toStringRef(keyBuf);
-  wpi::SmallVector<wpi::StringRef, 16> parts;
-  keyStr.split(parts, PATH_SEPARATOR_CHAR, -1, false);
+  wpi::SmallVector<std::string_view, 16> parts;
+  wpi::split(key, parts, PATH_SEPARATOR_CHAR, -1, false);
   for (auto i = parts.begin(); i != parts.end(); ++i) {
     buf.append(i->begin(), i->end());
     buf.push_back(PATH_SEPARATOR_CHAR);
   }
   // remove trailing slash if the input key didn't have one
-  if (!keyStr.empty() && keyStr.back() != PATH_SEPARATOR_CHAR) {
+  if (!key.empty() && key.back() != PATH_SEPARATOR_CHAR) {
     buf.pop_back();
   }
-  return wpi::StringRef(buf.data(), buf.size());
+  return {buf.data(), buf.size()};
 }
 
-std::vector<std::string> NetworkTable::GetHierarchy(const wpi::Twine& key) {
+std::vector<std::string> NetworkTable::GetHierarchy(std::string_view key) {
   std::vector<std::string> hierarchy;
   hierarchy.emplace_back(1, PATH_SEPARATOR_CHAR);
   // for each path element, add it to the end of what we built previously
-  wpi::SmallString<128> keyBuf;
-  wpi::StringRef keyStr = key.toStringRef(keyBuf);
   wpi::SmallString<128> path;
-  wpi::SmallVector<wpi::StringRef, 16> parts;
-  keyStr.split(parts, PATH_SEPARATOR_CHAR, -1, false);
+  wpi::SmallVector<std::string_view, 16> parts;
+  wpi::split(key, parts, PATH_SEPARATOR_CHAR, -1, false);
   if (!parts.empty()) {
     for (auto i = parts.begin(); i != parts.end(); ++i) {
       path += PATH_SEPARATOR_CHAR;
@@ -68,7 +66,7 @@ std::vector<std::string> NetworkTable::GetHierarchy(const wpi::Twine& key) {
       hierarchy.emplace_back(path.str());
     }
     // handle trailing slash
-    if (keyStr.back() == PATH_SEPARATOR_CHAR) {
+    if (key.back() == PATH_SEPARATOR_CHAR) {
       path += PATH_SEPARATOR_CHAR;
       hierarchy.emplace_back(path.str());
     }
@@ -76,9 +74,9 @@ std::vector<std::string> NetworkTable::GetHierarchy(const wpi::Twine& key) {
   return hierarchy;
 }
 
-NetworkTable::NetworkTable(NT_Inst inst, const wpi::Twine& path,
+NetworkTable::NetworkTable(NT_Inst inst, std::string_view path,
                            const private_init&)
-    : m_inst(inst), m_path(path.str()) {}
+    : m_inst(inst), m_path(path) {}
 
 NetworkTable::~NetworkTable() {
   for (auto i : m_listeners) {
@@ -90,14 +88,13 @@ NetworkTableInstance NetworkTable::GetInstance() const {
   return NetworkTableInstance{m_inst};
 }
 
-NetworkTableEntry NetworkTable::GetEntry(const wpi::Twine& key) const {
-  wpi::SmallString<128> keyBuf;
-  wpi::StringRef keyStr = key.toStringRef(keyBuf);
+NetworkTableEntry NetworkTable::GetEntry(std::string_view key) const {
   std::scoped_lock lock(m_mutex);
-  NT_Entry& entry = m_entries[keyStr];
+  NT_Entry& entry = m_entries[key];
   if (entry == 0) {
-    entry =
-        nt::GetEntry(m_inst, m_path + wpi::Twine(PATH_SEPARATOR_CHAR) + keyStr);
+    fmt::memory_buffer buf;
+    fmt::format_to(buf, "{}/{}", m_path, key);
+    entry = nt::GetEntry(m_inst, {buf.data(), buf.size()});
   }
   return NetworkTableEntry{entry};
 }
@@ -106,10 +103,10 @@ NT_EntryListener NetworkTable::AddEntryListener(TableEntryListener listener,
                                                 unsigned int flags) const {
   size_t prefix_len = m_path.size() + 1;
   return nt::AddEntryListener(
-      m_inst, m_path + wpi::Twine(PATH_SEPARATOR_CHAR),
+      m_inst, fmt::format("{}/", m_path),
       [=](const EntryNotification& event) {
-        wpi::StringRef relative_key = event.name.substr(prefix_len);
-        if (relative_key.find(PATH_SEPARATOR_CHAR) != wpi::StringRef::npos) {
+        auto relative_key = std::string_view{event.name}.substr(prefix_len);
+        if (relative_key.find(PATH_SEPARATOR_CHAR) != std::string_view::npos) {
           return;
         }
         listener(const_cast<NetworkTable*>(this), relative_key,
@@ -118,7 +115,7 @@ NT_EntryListener NetworkTable::AddEntryListener(TableEntryListener listener,
       flags);
 }
 
-NT_EntryListener NetworkTable::AddEntryListener(const wpi::Twine& key,
+NT_EntryListener NetworkTable::AddEntryListener(std::string_view key,
                                                 TableEntryListener listener,
                                                 unsigned int flags) const {
   size_t prefix_len = m_path.size() + 1;
@@ -126,8 +123,9 @@ NT_EntryListener NetworkTable::AddEntryListener(const wpi::Twine& key,
   return nt::AddEntryListener(
       entry.GetHandle(),
       [=](const EntryNotification& event) {
-        listener(const_cast<NetworkTable*>(this), event.name.substr(prefix_len),
-                 entry, event.value, event.flags);
+        listener(const_cast<NetworkTable*>(this),
+                 std::string_view{event.name}.substr(prefix_len), entry,
+                 event.value, event.flags);
       },
       flags);
 }
@@ -149,14 +147,14 @@ NT_EntryListener NetworkTable::AddSubTableListener(TableListener listener,
     flags |= NT_NOTIFY_LOCAL;
   }
   NT_EntryListener id = nt::AddEntryListener(
-      m_inst, m_path + wpi::Twine(PATH_SEPARATOR_CHAR),
+      m_inst, fmt::format("{}/", m_path),
       [=](const EntryNotification& event) {
-        wpi::StringRef relative_key = event.name.substr(prefix_len);
+        auto relative_key = std::string_view{event.name}.substr(prefix_len);
         auto end_sub_table = relative_key.find(PATH_SEPARATOR_CHAR);
-        if (end_sub_table == wpi::StringRef::npos) {
+        if (end_sub_table == std::string_view::npos) {
           return;
         }
-        wpi::StringRef sub_table_key = relative_key.substr(0, end_sub_table);
+        auto sub_table_key = relative_key.substr(0, end_sub_table);
         if (notified_tables->find(sub_table_key) == notified_tables->end()) {
           return;
         }
@@ -176,39 +174,33 @@ void NetworkTable::RemoveTableListener(NT_EntryListener listener) {
 }
 
 std::shared_ptr<NetworkTable> NetworkTable::GetSubTable(
-    const wpi::Twine& key) const {
+    std::string_view key) const {
   return std::make_shared<NetworkTable>(
-      m_inst, m_path + wpi::Twine(PATH_SEPARATOR_CHAR) + key, private_init{});
+      m_inst, fmt::format("{}/{}", m_path, key), private_init{});
 }
 
-bool NetworkTable::ContainsKey(const wpi::Twine& key) const {
-  if (key.isTriviallyEmpty() ||
-      (key.isSingleStringRef() && key.getSingleStringRef().empty())) {
+bool NetworkTable::ContainsKey(std::string_view key) const {
+  if (key.empty()) {
     return false;
   }
   return GetEntry(key).Exists();
 }
 
-bool NetworkTable::ContainsSubTable(const wpi::Twine& key) const {
-  return !GetEntryInfo(m_inst,
-                       m_path + wpi::Twine(PATH_SEPARATOR_CHAR) + key +
-                           wpi::Twine(PATH_SEPARATOR_CHAR),
-                       0)
-              .empty();
+bool NetworkTable::ContainsSubTable(std::string_view key) const {
+  return !GetEntryInfo(m_inst, fmt::format("{}/{}/", m_path, key), 0).empty();
 }
 
 std::vector<std::string> NetworkTable::GetKeys(int types) const {
   std::vector<std::string> keys;
   size_t prefix_len = m_path.size() + 1;
-  auto infos =
-      GetEntryInfo(m_inst, m_path + wpi::Twine(PATH_SEPARATOR_CHAR), types);
+  auto infos = GetEntryInfo(m_inst, fmt::format("{}/", m_path), types);
   std::scoped_lock lock(m_mutex);
   for (auto& info : infos) {
-    auto relative_key = wpi::StringRef(info.name).substr(prefix_len);
-    if (relative_key.find(PATH_SEPARATOR_CHAR) != wpi::StringRef::npos) {
+    auto relative_key = std::string_view{info.name}.substr(prefix_len);
+    if (relative_key.find(PATH_SEPARATOR_CHAR) != std::string_view::npos) {
       continue;
     }
-    keys.push_back(relative_key);
+    keys.emplace_back(relative_key);
     m_entries[relative_key] = info.entry;
   }
   return keys;
@@ -217,169 +209,167 @@ std::vector<std::string> NetworkTable::GetKeys(int types) const {
 std::vector<std::string> NetworkTable::GetSubTables() const {
   std::vector<std::string> keys;
   size_t prefix_len = m_path.size() + 1;
-  for (auto& entry :
-       GetEntryInfo(m_inst, m_path + wpi::Twine(PATH_SEPARATOR_CHAR), 0)) {
-    auto relative_key = wpi::StringRef(entry.name).substr(prefix_len);
+  for (auto& entry : GetEntryInfo(m_inst, fmt::format("{}/", m_path), 0)) {
+    auto relative_key = std::string_view{entry.name}.substr(prefix_len);
     size_t end_subtable = relative_key.find(PATH_SEPARATOR_CHAR);
-    if (end_subtable == wpi::StringRef::npos) {
+    if (end_subtable == std::string_view::npos) {
       continue;
     }
-    keys.push_back(relative_key.substr(0, end_subtable));
+    keys.emplace_back(relative_key.substr(0, end_subtable));
   }
   return keys;
 }
 
-void NetworkTable::SetPersistent(wpi::StringRef key) {
+void NetworkTable::SetPersistent(std::string_view key) {
   GetEntry(key).SetPersistent();
 }
 
-void NetworkTable::ClearPersistent(wpi::StringRef key) {
+void NetworkTable::ClearPersistent(std::string_view key) {
   GetEntry(key).ClearPersistent();
 }
 
-bool NetworkTable::IsPersistent(wpi::StringRef key) const {
+bool NetworkTable::IsPersistent(std::string_view key) const {
   return GetEntry(key).IsPersistent();
 }
 
-void NetworkTable::SetFlags(wpi::StringRef key, unsigned int flags) {
+void NetworkTable::SetFlags(std::string_view key, unsigned int flags) {
   GetEntry(key).SetFlags(flags);
 }
 
-void NetworkTable::ClearFlags(wpi::StringRef key, unsigned int flags) {
+void NetworkTable::ClearFlags(std::string_view key, unsigned int flags) {
   GetEntry(key).ClearFlags(flags);
 }
 
-unsigned int NetworkTable::GetFlags(wpi::StringRef key) const {
+unsigned int NetworkTable::GetFlags(std::string_view key) const {
   return GetEntry(key).GetFlags();
 }
 
-void NetworkTable::Delete(const wpi::Twine& key) {
+void NetworkTable::Delete(std::string_view key) {
   GetEntry(key).Delete();
 }
 
-bool NetworkTable::PutNumber(wpi::StringRef key, double value) {
+bool NetworkTable::PutNumber(std::string_view key, double value) {
   return GetEntry(key).SetDouble(value);
 }
 
-bool NetworkTable::SetDefaultNumber(wpi::StringRef key, double defaultValue) {
+bool NetworkTable::SetDefaultNumber(std::string_view key, double defaultValue) {
   return GetEntry(key).SetDefaultDouble(defaultValue);
 }
 
-double NetworkTable::GetNumber(wpi::StringRef key, double defaultValue) const {
+double NetworkTable::GetNumber(std::string_view key,
+                               double defaultValue) const {
   return GetEntry(key).GetDouble(defaultValue);
 }
 
-bool NetworkTable::PutString(wpi::StringRef key, wpi::StringRef value) {
+bool NetworkTable::PutString(std::string_view key, std::string_view value) {
   return GetEntry(key).SetString(value);
 }
 
-bool NetworkTable::SetDefaultString(wpi::StringRef key,
-                                    wpi::StringRef defaultValue) {
+bool NetworkTable::SetDefaultString(std::string_view key,
+                                    std::string_view defaultValue) {
   return GetEntry(key).SetDefaultString(defaultValue);
 }
 
-std::string NetworkTable::GetString(wpi::StringRef key,
-                                    wpi::StringRef defaultValue) const {
+std::string NetworkTable::GetString(std::string_view key,
+                                    std::string_view defaultValue) const {
   return GetEntry(key).GetString(defaultValue);
 }
 
-bool NetworkTable::PutBoolean(wpi::StringRef key, bool value) {
+bool NetworkTable::PutBoolean(std::string_view key, bool value) {
   return GetEntry(key).SetBoolean(value);
 }
 
-bool NetworkTable::SetDefaultBoolean(wpi::StringRef key, bool defaultValue) {
+bool NetworkTable::SetDefaultBoolean(std::string_view key, bool defaultValue) {
   return GetEntry(key).SetDefaultBoolean(defaultValue);
 }
 
-bool NetworkTable::GetBoolean(wpi::StringRef key, bool defaultValue) const {
+bool NetworkTable::GetBoolean(std::string_view key, bool defaultValue) const {
   return GetEntry(key).GetBoolean(defaultValue);
 }
 
-bool NetworkTable::PutBooleanArray(wpi::StringRef key,
+bool NetworkTable::PutBooleanArray(std::string_view key,
                                    wpi::ArrayRef<int> value) {
   return GetEntry(key).SetBooleanArray(value);
 }
 
-bool NetworkTable::SetDefaultBooleanArray(wpi::StringRef key,
+bool NetworkTable::SetDefaultBooleanArray(std::string_view key,
                                           wpi::ArrayRef<int> defaultValue) {
   return GetEntry(key).SetDefaultBooleanArray(defaultValue);
 }
 
 std::vector<int> NetworkTable::GetBooleanArray(
-    wpi::StringRef key, wpi::ArrayRef<int> defaultValue) const {
+    std::string_view key, wpi::ArrayRef<int> defaultValue) const {
   return GetEntry(key).GetBooleanArray(defaultValue);
 }
 
-bool NetworkTable::PutNumberArray(wpi::StringRef key,
+bool NetworkTable::PutNumberArray(std::string_view key,
                                   wpi::ArrayRef<double> value) {
   return GetEntry(key).SetDoubleArray(value);
 }
 
-bool NetworkTable::SetDefaultNumberArray(wpi::StringRef key,
+bool NetworkTable::SetDefaultNumberArray(std::string_view key,
                                          wpi::ArrayRef<double> defaultValue) {
   return GetEntry(key).SetDefaultDoubleArray(defaultValue);
 }
 
 std::vector<double> NetworkTable::GetNumberArray(
-    wpi::StringRef key, wpi::ArrayRef<double> defaultValue) const {
+    std::string_view key, wpi::ArrayRef<double> defaultValue) const {
   return GetEntry(key).GetDoubleArray(defaultValue);
 }
 
-bool NetworkTable::PutStringArray(wpi::StringRef key,
+bool NetworkTable::PutStringArray(std::string_view key,
                                   wpi::ArrayRef<std::string> value) {
   return GetEntry(key).SetStringArray(value);
 }
 
 bool NetworkTable::SetDefaultStringArray(
-    wpi::StringRef key, wpi::ArrayRef<std::string> defaultValue) {
+    std::string_view key, wpi::ArrayRef<std::string> defaultValue) {
   return GetEntry(key).SetDefaultStringArray(defaultValue);
 }
 
 std::vector<std::string> NetworkTable::GetStringArray(
-    wpi::StringRef key, wpi::ArrayRef<std::string> defaultValue) const {
+    std::string_view key, wpi::ArrayRef<std::string> defaultValue) const {
   return GetEntry(key).GetStringArray(defaultValue);
 }
 
-bool NetworkTable::PutRaw(wpi::StringRef key, wpi::StringRef value) {
+bool NetworkTable::PutRaw(std::string_view key, std::string_view value) {
   return GetEntry(key).SetRaw(value);
 }
 
-bool NetworkTable::SetDefaultRaw(wpi::StringRef key,
-                                 wpi::StringRef defaultValue) {
+bool NetworkTable::SetDefaultRaw(std::string_view key,
+                                 std::string_view defaultValue) {
   return GetEntry(key).SetDefaultRaw(defaultValue);
 }
 
-std::string NetworkTable::GetRaw(wpi::StringRef key,
-                                 wpi::StringRef defaultValue) const {
+std::string NetworkTable::GetRaw(std::string_view key,
+                                 std::string_view defaultValue) const {
   return GetEntry(key).GetRaw(defaultValue);
 }
 
-bool NetworkTable::PutValue(const wpi::Twine& key,
+bool NetworkTable::PutValue(std::string_view key,
                             std::shared_ptr<Value> value) {
   return GetEntry(key).SetValue(value);
 }
 
-bool NetworkTable::SetDefaultValue(const wpi::Twine& key,
+bool NetworkTable::SetDefaultValue(std::string_view key,
                                    std::shared_ptr<Value> defaultValue) {
   return GetEntry(key).SetDefaultValue(defaultValue);
 }
 
-std::shared_ptr<Value> NetworkTable::GetValue(const wpi::Twine& key) const {
+std::shared_ptr<Value> NetworkTable::GetValue(std::string_view key) const {
   return GetEntry(key).GetValue();
 }
 
-wpi::StringRef NetworkTable::GetPath() const {
+std::string_view NetworkTable::GetPath() const {
   return m_path;
 }
 
-const char* NetworkTable::SaveEntries(const wpi::Twine& filename) const {
-  return nt::SaveEntries(m_inst, filename,
-                         m_path + wpi::Twine(PATH_SEPARATOR_CHAR));
+const char* NetworkTable::SaveEntries(std::string_view filename) const {
+  return nt::SaveEntries(m_inst, filename, fmt::format("{}/", m_path));
 }
 
 const char* NetworkTable::LoadEntries(
-    const wpi::Twine& filename,
+    std::string_view filename,
     std::function<void(size_t line, const char* msg)> warn) {
-  return nt::LoadEntries(m_inst, filename,
-                         m_path + wpi::Twine(PATH_SEPARATOR_CHAR), warn);
+  return nt::LoadEntries(m_inst, filename, fmt::format("{}/", m_path), warn);
 }
diff --git a/ntcore/src/main/native/cpp/networktables/NetworkTableInstance.cpp b/ntcore/src/main/native/cpp/networktables/NetworkTableInstance.cpp
index 8a3d985dc6..4ff8f7551b 100644
--- a/ntcore/src/main/native/cpp/networktables/NetworkTableInstance.cpp
+++ b/ntcore/src/main/native/cpp/networktables/NetworkTableInstance.cpp
@@ -4,42 +4,37 @@
 
 #include "networktables/NetworkTableInstance.h"
 
-#include <wpi/SmallString.h>
+#include <fmt/format.h>
+#include <wpi/SmallVector.h>
 
 using namespace nt;
 
 std::shared_ptr<NetworkTable> NetworkTableInstance::GetTable(
-    const wpi::Twine& key) const {
-  wpi::StringRef simple;
-  bool isSimple = key.isSingleStringRef();
-  if (isSimple) {
-    simple = key.getSingleStringRef();
-  }
-  if (isSimple && (simple.empty() || simple == "/")) {
+    std::string_view key) const {
+  if (key.empty() || key == "/") {
     return std::make_shared<NetworkTable>(m_handle, "",
                                           NetworkTable::private_init{});
-  } else if (isSimple && simple[0] == NetworkTable::PATH_SEPARATOR_CHAR) {
+  } else if (key.front() == NetworkTable::PATH_SEPARATOR_CHAR) {
     return std::make_shared<NetworkTable>(m_handle, key,
                                           NetworkTable::private_init{});
   } else {
-    return std::make_shared<NetworkTable>(
-        m_handle, wpi::Twine(NetworkTable::PATH_SEPARATOR_CHAR) + key,
-        NetworkTable::private_init{});
+    return std::make_shared<NetworkTable>(m_handle, fmt::format("/{}", key),
+                                          NetworkTable::private_init{});
   }
 }
 
-void NetworkTableInstance::StartClient(wpi::ArrayRef<wpi::StringRef> servers,
+void NetworkTableInstance::StartClient(wpi::ArrayRef<std::string_view> servers,
                                        unsigned int port) {
-  wpi::SmallVector<std::pair<wpi::StringRef, unsigned int>, 8> server_ports;
+  wpi::SmallVector<std::pair<std::string_view, unsigned int>, 8> server_ports;
   for (const auto& server : servers) {
     server_ports.emplace_back(std::make_pair(server, port));
   }
   StartClient(server_ports);
 }
 
-void NetworkTableInstance::SetServer(wpi::ArrayRef<wpi::StringRef> servers,
+void NetworkTableInstance::SetServer(wpi::ArrayRef<std::string_view> servers,
                                      unsigned int port) {
-  wpi::SmallVector<std::pair<wpi::StringRef, unsigned int>, 8> server_ports;
+  wpi::SmallVector<std::pair<std::string_view, unsigned int>, 8> server_ports;
   for (const auto& server : servers) {
     server_ports.emplace_back(std::make_pair(server, port));
   }
@@ -47,7 +42,7 @@ void NetworkTableInstance::SetServer(wpi::ArrayRef<wpi::StringRef> servers,
 }
 
 NT_EntryListener NetworkTableInstance::AddEntryListener(
-    const wpi::Twine& prefix,
+    std::string_view prefix,
     std::function<void(const EntryNotification& event)> callback,
     unsigned int flags) const {
   return ::nt::AddEntryListener(m_handle, prefix, callback, flags);
diff --git a/ntcore/src/main/native/cpp/ntcore_c.cpp b/ntcore/src/main/native/cpp/ntcore_c.cpp
index d41fc9774c..ae48b1cce6 100644
--- a/ntcore/src/main/native/cpp/ntcore_c.cpp
+++ b/ntcore/src/main/native/cpp/ntcore_c.cpp
@@ -6,6 +6,7 @@
 
 #include <cassert>
 #include <cstdlib>
+#include <string_view>
 
 #include <wpi/MemAlloc.h>
 #include <wpi/timestamp.h>
@@ -17,7 +18,7 @@ using namespace nt;
 
 // Conversion helpers
 
-static void ConvertToC(wpi::StringRef in, char** out) {
+static void ConvertToC(std::string_view in, char** out) {
   *out = static_cast<char*>(wpi::safe_malloc(in.size() + 1));
   std::memmove(*out, in.data(), in.size());  // NOLINT
   (*out)[in.size()] = '\0';
@@ -192,12 +193,12 @@ NT_Inst NT_GetInstanceFromHandle(NT_Handle handle) {
  */
 
 NT_Entry NT_GetEntry(NT_Inst inst, const char* name, size_t name_len) {
-  return nt::GetEntry(inst, wpi::StringRef(name, name_len));
+  return nt::GetEntry(inst, {name, name_len});
 }
 
 NT_Entry* NT_GetEntries(NT_Inst inst, const char* prefix, size_t prefix_len,
                         unsigned int types, size_t* count) {
-  auto info_v = nt::GetEntries(inst, wpi::StringRef(prefix, prefix_len), types);
+  auto info_v = nt::GetEntries(inst, {prefix, prefix_len}, types);
   *count = info_v.size();
   if (info_v.size() == 0) {
     return nullptr;
@@ -266,8 +267,7 @@ void NT_DeleteAllEntries(NT_Inst inst) {
 struct NT_EntryInfo* NT_GetEntryInfo(NT_Inst inst, const char* prefix,
                                      size_t prefix_len, unsigned int types,
                                      size_t* count) {
-  auto info_v =
-      nt::GetEntryInfo(inst, wpi::StringRef(prefix, prefix_len), types);
+  auto info_v = nt::GetEntryInfo(inst, {prefix, prefix_len}, types);
   return ConvertToC<NT_EntryInfo>(info_v, count);
 }
 
@@ -289,7 +289,7 @@ NT_EntryListener NT_AddEntryListener(NT_Inst inst, const char* prefix,
                                      NT_EntryListenerCallback callback,
                                      unsigned int flags) {
   return nt::AddEntryListener(
-      inst, wpi::StringRef(prefix, prefix_len),
+      inst, {prefix, prefix_len},
       [=](const EntryNotification& event) {
         NT_EntryNotification c_event;
         ConvertToC(event, &c_event);
@@ -325,8 +325,7 @@ NT_EntryListener NT_AddPolledEntryListener(NT_EntryListenerPoller poller,
                                            const char* prefix,
                                            size_t prefix_len,
                                            unsigned int flags) {
-  return nt::AddPolledEntryListener(poller, wpi::StringRef(prefix, prefix_len),
-                                    flags);
+  return nt::AddPolledEntryListener(poller, {prefix, prefix_len}, flags);
 }
 
 NT_EntryListener NT_AddPolledEntryListenerSingle(NT_EntryListenerPoller poller,
@@ -422,13 +421,12 @@ NT_Bool NT_WaitForConnectionListenerQueue(NT_Inst inst, double timeout) {
 
 void NT_CreateRpc(NT_Entry entry, const char* def, size_t def_len, void* data,
                   NT_RpcCallback callback) {
-  nt::CreateRpc(entry, wpi::StringRef(def, def_len),
-                [=](const RpcAnswer& answer) {
-                  NT_RpcAnswer answer_c;
-                  ConvertToC(answer, &answer_c);
-                  callback(data, &answer_c);
-                  NT_DisposeRpcAnswer(&answer_c);
-                });
+  nt::CreateRpc(entry, {def, def_len}, [=](const RpcAnswer& answer) {
+    NT_RpcAnswer answer_c;
+    ConvertToC(answer, &answer_c);
+    callback(data, &answer_c);
+    NT_DisposeRpcAnswer(&answer_c);
+  });
 }
 
 NT_RpcCallPoller NT_CreateRpcCallPoller(NT_Inst inst) {
@@ -441,7 +439,7 @@ void NT_DestroyRpcCallPoller(NT_RpcCallPoller poller) {
 
 void NT_CreatePolledRpc(NT_Entry entry, const char* def, size_t def_len,
                         NT_RpcCallPoller poller) {
-  nt::CreatePolledRpc(entry, wpi::StringRef(def, def_len), poller);
+  nt::CreatePolledRpc(entry, {def, def_len}, poller);
 }
 
 NT_RpcAnswer* NT_PollRpc(NT_RpcCallPoller poller, size_t* len) {
@@ -467,11 +465,11 @@ NT_Bool NT_WaitForRpcCallQueue(NT_Inst inst, double timeout) {
 
 NT_Bool NT_PostRpcResponse(NT_Entry entry, NT_RpcCall call, const char* result,
                            size_t result_len) {
-  return nt::PostRpcResponse(entry, call, wpi::StringRef(result, result_len));
+  return nt::PostRpcResponse(entry, call, {result, result_len});
 }
 
 NT_RpcCall NT_CallRpc(NT_Entry entry, const char* params, size_t params_len) {
-  return nt::CallRpc(entry, wpi::StringRef(params, params_len));
+  return nt::CallRpc(entry, {params, params_len});
 }
 
 char* NT_GetRpcResult(NT_Entry entry, NT_RpcCall call, size_t* result_len) {
@@ -522,7 +520,7 @@ char* NT_PackRpcDefinition(const NT_RpcDefinition* def, size_t* packed_len) {
 NT_Bool NT_UnpackRpcDefinition(const char* packed, size_t packed_len,
                                NT_RpcDefinition* def) {
   nt::RpcDefinition def_v;
-  if (!nt::UnpackRpcDefinition(wpi::StringRef(packed, packed_len), &def_v)) {
+  if (!nt::UnpackRpcDefinition({packed, packed_len}, &def_v)) {
     return 0;
   }
 
@@ -552,7 +550,7 @@ char* NT_PackRpcValues(const NT_Value** values, size_t values_len,
 
 NT_Value** NT_UnpackRpcValues(const char* packed, size_t packed_len,
                               const NT_Type* types, size_t types_len) {
-  auto values_v = nt::UnpackRpcValues(wpi::StringRef(packed, packed_len),
+  auto values_v = nt::UnpackRpcValues({packed, packed_len},
                                       wpi::ArrayRef<NT_Type>(types, types_len));
   if (values_v.size() == 0) {
     return nullptr;
@@ -573,7 +571,7 @@ NT_Value** NT_UnpackRpcValues(const char* packed, size_t packed_len,
  */
 
 void NT_SetNetworkIdentity(NT_Inst inst, const char* name, size_t name_len) {
-  nt::SetNetworkIdentity(inst, wpi::StringRef(name, name_len));
+  nt::SetNetworkIdentity(inst, {name, name_len});
 }
 
 unsigned int NT_GetNetworkMode(NT_Inst inst) {
@@ -607,7 +605,7 @@ void NT_StartClient(NT_Inst inst, const char* server_name, unsigned int port) {
 
 void NT_StartClientMulti(NT_Inst inst, size_t count, const char** server_names,
                          const unsigned int* ports) {
-  std::vector<std::pair<wpi::StringRef, unsigned int>> servers;
+  std::vector<std::pair<std::string_view, unsigned int>> servers;
   servers.reserve(count);
   for (size_t i = 0; i < count; ++i) {
     servers.emplace_back(std::make_pair(server_names[i], ports[i]));
@@ -629,7 +627,7 @@ void NT_SetServer(NT_Inst inst, const char* server_name, unsigned int port) {
 
 void NT_SetServerMulti(NT_Inst inst, size_t count, const char** server_names,
                        const unsigned int* ports) {
-  std::vector<std::pair<wpi::StringRef, unsigned int>> servers;
+  std::vector<std::pair<std::string_view, unsigned int>> servers;
   servers.reserve(count);
   for (size_t i = 0; i < count; ++i) {
     servers.emplace_back(std::make_pair(server_names[i], ports[i]));
@@ -681,14 +679,13 @@ const char* NT_LoadPersistent(NT_Inst inst, const char* filename,
 
 const char* NT_SaveEntries(NT_Inst inst, const char* filename,
                            const char* prefix, size_t prefix_len) {
-  return nt::SaveEntries(inst, filename, wpi::StringRef(prefix, prefix_len));
+  return nt::SaveEntries(inst, filename, {prefix, prefix_len});
 }
 
 const char* NT_LoadEntries(NT_Inst inst, const char* filename,
                            const char* prefix, size_t prefix_len,
                            void (*warn)(size_t line, const char* msg)) {
-  return nt::LoadEntries(inst, filename, wpi::StringRef(prefix, prefix_len),
-                         warn);
+  return nt::LoadEntries(inst, filename, {prefix, prefix_len}, warn);
 }
 
 /*
@@ -954,24 +951,20 @@ NT_Bool NT_SetEntryBoolean(NT_Entry entry, uint64_t time, NT_Bool v_boolean,
 NT_Bool NT_SetEntryString(NT_Entry entry, uint64_t time, const char* str,
                           size_t str_len, NT_Bool force) {
   if (force != 0) {
-    nt::SetEntryTypeValue(
-        entry, Value::MakeString(wpi::StringRef(str, str_len), time));
+    nt::SetEntryTypeValue(entry, Value::MakeString({str, str_len}, time));
     return 1;
   } else {
-    return nt::SetEntryValue(
-        entry, Value::MakeString(wpi::StringRef(str, str_len), time));
+    return nt::SetEntryValue(entry, Value::MakeString({str, str_len}, time));
   }
 }
 
 NT_Bool NT_SetEntryRaw(NT_Entry entry, uint64_t time, const char* raw,
                        size_t raw_len, NT_Bool force) {
   if (force != 0) {
-    nt::SetEntryTypeValue(entry,
-                          Value::MakeRaw(wpi::StringRef(raw, raw_len), time));
+    nt::SetEntryTypeValue(entry, Value::MakeRaw({raw, raw_len}, time));
     return 1;
   } else {
-    return nt::SetEntryValue(
-        entry, Value::MakeRaw(wpi::StringRef(raw, raw_len), time));
+    return nt::SetEntryValue(entry, Value::MakeRaw({raw, raw_len}, time));
   }
 }
 
@@ -1006,7 +999,7 @@ NT_Bool NT_SetEntryStringArray(NT_Entry entry, uint64_t time,
   std::vector<std::string> v;
   v.reserve(size);
   for (size_t i = 0; i < size; ++i) {
-    v.push_back(ConvertFromC(arr[i]));
+    v.emplace_back(ConvertFromC(arr[i]));
   }
 
   if (force != 0) {
@@ -1132,14 +1125,13 @@ NT_Bool NT_SetDefaultEntryString(NT_Entry entry, uint64_t time,
                                  const char* default_value,
                                  size_t default_len) {
   return nt::SetDefaultEntryValue(
-      entry,
-      Value::MakeString(wpi::StringRef(default_value, default_len), time));
+      entry, Value::MakeString({default_value, default_len}, time));
 }
 
 NT_Bool NT_SetDefaultEntryRaw(NT_Entry entry, uint64_t time,
                               const char* default_value, size_t default_len) {
   return nt::SetDefaultEntryValue(
-      entry, Value::MakeRaw(wpi::StringRef(default_value, default_len), time));
+      entry, Value::MakeRaw({default_value, default_len}, time));
 }
 
 NT_Bool NT_SetDefaultEntryBooleanArray(NT_Entry entry, uint64_t time,
@@ -1164,7 +1156,7 @@ NT_Bool NT_SetDefaultEntryStringArray(NT_Entry entry, uint64_t time,
   std::vector<std::string> vec;
   vec.reserve(default_size);
   for (size_t i = 0; i < default_size; ++i) {
-    vec.push_back(ConvertFromC(default_value[i]));
+    vec.emplace_back(ConvertFromC(default_value[i]));
   }
 
   return nt::SetDefaultEntryValue(entry,
diff --git a/ntcore/src/main/native/cpp/ntcore_cpp.cpp b/ntcore/src/main/native/cpp/ntcore_cpp.cpp
index cf1a7d5c16..619e996941 100644
--- a/ntcore/src/main/native/cpp/ntcore_cpp.cpp
+++ b/ntcore/src/main/native/cpp/ntcore_cpp.cpp
@@ -53,7 +53,7 @@ NT_Inst GetInstanceFromHandle(NT_Handle handle) {
  * Table Functions
  */
 
-NT_Entry GetEntry(NT_Inst inst, const wpi::Twine& name) {
+NT_Entry GetEntry(NT_Inst inst, std::string_view name) {
   int i = Handle{inst}.GetTypedInst(Handle::kInstance);
   auto ii = InstanceImpl::Get(i);
   if (!ii) {
@@ -67,7 +67,7 @@ NT_Entry GetEntry(NT_Inst inst, const wpi::Twine& name) {
   return Handle(i, id, Handle::kEntry);
 }
 
-std::vector<NT_Entry> GetEntries(NT_Inst inst, const wpi::Twine& prefix,
+std::vector<NT_Entry> GetEntries(NT_Inst inst, std::string_view prefix,
                                  unsigned int types) {
   int i = Handle{inst}.GetTypedInst(Handle::kInstance);
   auto ii = InstanceImpl::Get(i);
@@ -203,7 +203,7 @@ void DeleteAllEntries(NT_Inst inst) {
   ii->storage.DeleteAllEntries();
 }
 
-std::vector<EntryInfo> GetEntryInfo(NT_Inst inst, const wpi::Twine& prefix,
+std::vector<EntryInfo> GetEntryInfo(NT_Inst inst, std::string_view prefix,
                                     unsigned int types) {
   int i = Handle{inst}.GetTypedInst(Handle::kInstance);
   auto ii = InstanceImpl::Get(i);
@@ -236,7 +236,7 @@ EntryInfo GetEntryInfo(NT_Entry entry) {
  */
 
 NT_EntryListener AddEntryListener(
-    NT_Inst inst, const wpi::Twine& prefix,
+    NT_Inst inst, std::string_view prefix,
     std::function<void(const EntryNotification& event)> callback,
     unsigned int flags) {
   int i = Handle{inst}.GetTypedInst(Handle::kInstance);
@@ -288,7 +288,7 @@ void DestroyEntryListenerPoller(NT_EntryListenerPoller poller) {
 }
 
 NT_EntryListener AddPolledEntryListener(NT_EntryListenerPoller poller,
-                                        const wpi::Twine& prefix,
+                                        std::string_view prefix,
                                         unsigned int flags) {
   Handle handle{poller};
   int id = handle.GetTypedIndex(Handle::kEntryListenerPoller);
@@ -494,7 +494,7 @@ bool WaitForConnectionListenerQueue(NT_Inst inst, double timeout) {
  * Remote Procedure Call Functions
  */
 
-void CreateRpc(NT_Entry entry, wpi::StringRef def,
+void CreateRpc(NT_Entry entry, std::string_view def,
                std::function<void(const RpcAnswer& answer)> callback) {
   Handle handle{entry};
   int id = handle.GetTypedIndex(Handle::kEntry);
@@ -535,7 +535,7 @@ void DestroyRpcCallPoller(NT_RpcCallPoller poller) {
   ii->rpc_server.RemovePoller(id);
 }
 
-void CreatePolledRpc(NT_Entry entry, wpi::StringRef def,
+void CreatePolledRpc(NT_Entry entry, std::string_view def,
                      NT_RpcCallPoller poller) {
   Handle handle{entry};
   int id = handle.GetTypedIndex(Handle::kEntry);
@@ -608,7 +608,7 @@ bool WaitForRpcCallQueue(NT_Inst inst, double timeout) {
   return ii->rpc_server.WaitForQueue(timeout);
 }
 
-bool PostRpcResponse(NT_Entry entry, NT_RpcCall call, wpi::StringRef result) {
+bool PostRpcResponse(NT_Entry entry, NT_RpcCall call, std::string_view result) {
   Handle handle{entry};
   int id = handle.GetTypedIndex(Handle::kEntry);
   auto ii = InstanceImpl::Get(handle.GetInst());
@@ -628,7 +628,7 @@ bool PostRpcResponse(NT_Entry entry, NT_RpcCall call, wpi::StringRef result) {
   return ii->rpc_server.PostRpcResponse(id, call_uid, result);
 }
 
-NT_RpcCall CallRpc(NT_Entry entry, wpi::StringRef params) {
+NT_RpcCall CallRpc(NT_Entry entry, std::string_view params) {
   Handle handle{entry};
   int id = handle.GetTypedIndex(Handle::kEntry);
   int i = handle.GetInst();
@@ -734,10 +734,10 @@ std::string PackRpcDefinition(const RpcDefinition& def) {
     enc.WriteString(def.results[i].name);
   }
 
-  return enc.ToStringRef();
+  return std::string{enc.ToStringView()};
 }
 
-bool UnpackRpcDefinition(wpi::StringRef packed, RpcDefinition* def) {
+bool UnpackRpcDefinition(std::string_view packed, RpcDefinition* def) {
   wpi::raw_mem_istream is(packed.data(), packed.size());
   wpi::Logger logger;
   WireDecoder dec(is, 0x0300, logger);
@@ -797,11 +797,11 @@ std::string PackRpcValues(wpi::ArrayRef<std::shared_ptr<Value>> values) {
   for (auto& value : values) {
     enc.WriteValue(*value);
   }
-  return enc.ToStringRef();
+  return std::string{enc.ToStringView()};
 }
 
 std::vector<std::shared_ptr<Value>> UnpackRpcValues(
-    wpi::StringRef packed, wpi::ArrayRef<NT_Type> types) {
+    std::string_view packed, wpi::ArrayRef<NT_Type> types) {
   wpi::raw_mem_istream is(packed.data(), packed.size());
   wpi::Logger logger;
   WireDecoder dec(is, 0x0300, logger);
@@ -824,7 +824,7 @@ uint64_t Now() {
  * Client/Server Functions
  */
 
-void SetNetworkIdentity(NT_Inst inst, const wpi::Twine& name) {
+void SetNetworkIdentity(NT_Inst inst, std::string_view name) {
   auto ii = InstanceImpl::Get(Handle{inst}.GetTypedInst(Handle::kInstance));
   if (!ii) {
     return;
@@ -860,7 +860,7 @@ void StopLocal(NT_Inst inst) {
   ii->dispatcher.Stop();
 }
 
-void StartServer(NT_Inst inst, const wpi::Twine& persist_filename,
+void StartServer(NT_Inst inst, std::string_view persist_filename,
                  const char* listen_address, unsigned int port) {
   auto ii = InstanceImpl::Get(Handle{inst}.GetTypedInst(Handle::kInstance));
   if (!ii) {
@@ -900,7 +900,7 @@ void StartClient(NT_Inst inst, const char* server_name, unsigned int port) {
 
 void StartClient(
     NT_Inst inst,
-    wpi::ArrayRef<std::pair<wpi::StringRef, unsigned int>> servers) {
+    wpi::ArrayRef<std::pair<std::string_view, unsigned int>> servers) {
   auto ii = InstanceImpl::Get(Handle{inst}.GetTypedInst(Handle::kInstance));
   if (!ii) {
     return;
@@ -938,8 +938,9 @@ void SetServer(NT_Inst inst, const char* server_name, unsigned int port) {
   ii->dispatcher.SetServer(server_name, port);
 }
 
-void SetServer(NT_Inst inst,
-               wpi::ArrayRef<std::pair<wpi::StringRef, unsigned int>> servers) {
+void SetServer(
+    NT_Inst inst,
+    wpi::ArrayRef<std::pair<std::string_view, unsigned int>> servers) {
   auto ii = InstanceImpl::Get(Handle{inst}.GetTypedInst(Handle::kInstance));
   if (!ii) {
     return;
@@ -1015,7 +1016,7 @@ bool IsConnected(NT_Inst inst) {
  * Persistent Functions
  */
 
-const char* SavePersistent(NT_Inst inst, const wpi::Twine& filename) {
+const char* SavePersistent(NT_Inst inst, std::string_view filename) {
   auto ii = InstanceImpl::Get(Handle{inst}.GetTypedInst(Handle::kInstance));
   if (!ii) {
     return "invalid instance handle";
@@ -1025,7 +1026,7 @@ const char* SavePersistent(NT_Inst inst, const wpi::Twine& filename) {
 }
 
 const char* LoadPersistent(
-    NT_Inst inst, const wpi::Twine& filename,
+    NT_Inst inst, std::string_view filename,
     std::function<void(size_t line, const char* msg)> warn) {
   auto ii = InstanceImpl::Get(Handle{inst}.GetTypedInst(Handle::kInstance));
   if (!ii) {
@@ -1035,8 +1036,8 @@ const char* LoadPersistent(
   return ii->storage.LoadPersistent(filename, warn);
 }
 
-const char* SaveEntries(NT_Inst inst, const wpi::Twine& filename,
-                        const wpi::Twine& prefix) {
+const char* SaveEntries(NT_Inst inst, std::string_view filename,
+                        std::string_view prefix) {
   auto ii = InstanceImpl::Get(Handle{inst}.GetTypedInst(Handle::kInstance));
   if (!ii) {
     return "invalid instance handle";
@@ -1046,7 +1047,7 @@ const char* SaveEntries(NT_Inst inst, const wpi::Twine& filename,
 }
 
 const char* LoadEntries(
-    NT_Inst inst, const wpi::Twine& filename, const wpi::Twine& prefix,
+    NT_Inst inst, std::string_view filename, std::string_view prefix,
     std::function<void(size_t line, const char* msg)> warn) {
   auto ii = InstanceImpl::Get(Handle{inst}.GetTypedInst(Handle::kInstance));
   if (!ii) {
diff --git a/ntcore/src/main/native/cpp/ntcore_test.cpp b/ntcore/src/main/native/cpp/ntcore_test.cpp
index 08ebec75ab..00d07f7b27 100644
--- a/ntcore/src/main/native/cpp/ntcore_test.cpp
+++ b/ntcore/src/main/native/cpp/ntcore_test.cpp
@@ -12,7 +12,7 @@ extern "C" {
 struct NT_String* NT_GetStringForTesting(const char* string, int* struct_size) {
   struct NT_String* str =
       static_cast<NT_String*>(wpi::safe_calloc(1, sizeof(NT_String)));
-  nt::ConvertToC(wpi::StringRef(string), str);
+  nt::ConvertToC(string, str);
   *struct_size = sizeof(NT_String);
   return str;
 }
@@ -24,7 +24,7 @@ struct NT_EntryInfo* NT_GetEntryInfoForTesting(const char* name,
                                                int* struct_size) {
   struct NT_EntryInfo* entry_info =
       static_cast<NT_EntryInfo*>(wpi::safe_calloc(1, sizeof(NT_EntryInfo)));
-  nt::ConvertToC(wpi::StringRef(name), &entry_info->name);
+  nt::ConvertToC(name, &entry_info->name);
   entry_info->type = type;
   entry_info->flags = flags;
   entry_info->last_change = last_change;
@@ -42,8 +42,8 @@ struct NT_ConnectionInfo* NT_GetConnectionInfoForTesting(
     uint64_t last_update, unsigned int protocol_version, int* struct_size) {
   struct NT_ConnectionInfo* conn_info = static_cast<NT_ConnectionInfo*>(
       wpi::safe_calloc(1, sizeof(NT_ConnectionInfo)));
-  nt::ConvertToC(wpi::StringRef(remote_id), &conn_info->remote_id);
-  nt::ConvertToC(wpi::StringRef(remote_ip), &conn_info->remote_ip);
+  nt::ConvertToC(remote_id, &conn_info->remote_id);
+  nt::ConvertToC(remote_ip, &conn_info->remote_ip);
   conn_info->remote_port = remote_port;
   conn_info->last_update = last_update;
   conn_info->protocol_version = protocol_version;
@@ -86,7 +86,7 @@ struct NT_Value* NT_GetValueStringForTesting(uint64_t last_change,
       static_cast<NT_Value*>(wpi::safe_calloc(1, sizeof(NT_Value)));
   value->type = NT_STRING;
   value->last_change = last_change;
-  nt::ConvertToC(wpi::StringRef(str), &value->data.v_string);
+  nt::ConvertToC(str, &value->data.v_string);
   *struct_size = sizeof(NT_Value);
   return value;
 }
@@ -97,7 +97,7 @@ struct NT_Value* NT_GetValueRawForTesting(uint64_t last_change, const char* raw,
       static_cast<NT_Value*>(wpi::safe_calloc(1, sizeof(NT_Value)));
   value->type = NT_RAW;
   value->last_change = last_change;
-  nt::ConvertToC(wpi::StringRef(raw, raw_len), &value->data.v_string);
+  nt::ConvertToC(std::string_view(raw, raw_len), &value->data.v_string);
   *struct_size = sizeof(NT_Value);
   return value;
 }
@@ -164,7 +164,7 @@ static void CopyNtValue(const struct NT_Value* copy_from,
 
 static void CopyNtString(const struct NT_String* copy_from,
                          struct NT_String* copy_to) {
-  nt::ConvertToC(wpi::StringRef(copy_from->str, copy_from->len), copy_to);
+  nt::ConvertToC({copy_from->str, copy_from->len}, copy_to);
 }
 
 struct NT_RpcParamDef* NT_GetRpcParamDefForTesting(const char* name,
@@ -172,7 +172,7 @@ struct NT_RpcParamDef* NT_GetRpcParamDefForTesting(const char* name,
                                                    int* struct_size) {
   struct NT_RpcParamDef* def =
       static_cast<NT_RpcParamDef*>(wpi::safe_calloc(1, sizeof(NT_RpcParamDef)));
-  nt::ConvertToC(wpi::StringRef(name), &def->name);
+  nt::ConvertToC(name, &def->name);
   CopyNtValue(val, &def->def_value);
   *struct_size = sizeof(NT_RpcParamDef);
   return def;
@@ -189,7 +189,7 @@ struct NT_RpcResultDef* NT_GetRpcResultsDefForTesting(const char* name,
                                                       int* struct_size) {
   struct NT_RpcResultDef* def = static_cast<NT_RpcResultDef*>(
       wpi::safe_calloc(1, sizeof(NT_RpcResultDef)));
-  nt::ConvertToC(wpi::StringRef(name), &def->name);
+  nt::ConvertToC(name, &def->name);
   def->type = type;
   *struct_size = sizeof(NT_RpcResultDef);
   return def;
@@ -207,7 +207,7 @@ struct NT_RpcDefinition* NT_GetRpcDefinitionForTesting(
   struct NT_RpcDefinition* def = static_cast<NT_RpcDefinition*>(
       wpi::safe_calloc(1, sizeof(NT_RpcDefinition)));
   def->version = version;
-  nt::ConvertToC(wpi::StringRef(name), &def->name);
+  nt::ConvertToC(name, &def->name);
   def->num_params = num_params;
   def->params = static_cast<NT_RpcParamDef*>(
       wpi::safe_malloc(num_params * sizeof(NT_RpcParamDef)));
@@ -234,8 +234,8 @@ struct NT_RpcAnswer* NT_GetRpcAnswerForTesting(
       static_cast<NT_RpcAnswer*>(wpi::safe_calloc(1, sizeof(NT_RpcAnswer)));
   info->entry = rpc_id;
   info->call = call_uid;
-  nt::ConvertToC(wpi::StringRef(name), &info->name);
-  nt::ConvertToC(wpi::StringRef(params, params_len), &info->params);
+  nt::ConvertToC(name, &info->name);
+  nt::ConvertToC({params, params_len}, &info->params);
   *struct_size = sizeof(NT_RpcAnswer);
   return info;
 }
diff --git a/ntcore/src/main/native/include/networktables/NetworkTable.h b/ntcore/src/main/native/include/networktables/NetworkTable.h
index 664c98b563..7ac4e7eb14 100644
--- a/ntcore/src/main/native/include/networktables/NetworkTable.h
+++ b/ntcore/src/main/native/include/networktables/NetworkTable.h
@@ -8,12 +8,12 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
 #include <wpi/ArrayRef.h>
 #include <wpi/StringMap.h>
-#include <wpi/Twine.h>
 #include <wpi/mutex.h>
 
 #include "networktables/NetworkTableEntry.h"
@@ -54,7 +54,7 @@ class NetworkTable final {
    * @param key key
    * @return base name
    */
-  static wpi::StringRef BasenameKey(wpi::StringRef key);
+  static std::string_view BasenameKey(std::string_view key);
 
   /**
    * Normalizes an network table key to contain no consecutive slashes and
@@ -72,12 +72,12 @@ class NetworkTable final {
    *                         with a leading slash
    * @return normalized key
    */
-  static std::string NormalizeKey(const wpi::Twine& key,
+  static std::string NormalizeKey(std::string_view key,
                                   bool withLeadingSlash = true);
 
-  static wpi::StringRef NormalizeKey(const wpi::Twine& key,
-                                     wpi::SmallVectorImpl<char>& buf,
-                                     bool withLeadingSlash = true);
+  static std::string_view NormalizeKey(std::string_view key,
+                                       wpi::SmallVectorImpl<char>& buf,
+                                       bool withLeadingSlash = true);
 
   /**
    * Gets a list of the names of all the super tables of a given key. For
@@ -87,13 +87,13 @@ class NetworkTable final {
    * @param key the key
    * @return List of super tables
    */
-  static std::vector<std::string> GetHierarchy(const wpi::Twine& key);
+  static std::vector<std::string> GetHierarchy(std::string_view key);
 
   /**
    * Constructor.  Use NetworkTableInstance::GetTable() or GetSubTable()
    * instead.
    */
-  NetworkTable(NT_Inst inst, const wpi::Twine& path, const private_init&);
+  NetworkTable(NT_Inst inst, std::string_view path, const private_init&);
   virtual ~NetworkTable();
 
   /**
@@ -114,7 +114,7 @@ class NetworkTable final {
    * @param key the key name
    * @return Network table entry.
    */
-  NetworkTableEntry GetEntry(const wpi::Twine& key) const;
+  NetworkTableEntry GetEntry(std::string_view key) const;
 
   /**
    * Listen to keys only within this table.
@@ -134,7 +134,7 @@ class NetworkTable final {
    * @param flags       EntryListenerFlags bitmask
    * @return Listener handle
    */
-  NT_EntryListener AddEntryListener(const wpi::Twine& key,
+  NT_EntryListener AddEntryListener(std::string_view key,
                                     TableEntryListener listener,
                                     unsigned int flags) const;
 
@@ -171,7 +171,7 @@ class NetworkTable final {
    * @param key the key name
    * @return the networktable to be returned
    */
-  std::shared_ptr<NetworkTable> GetSubTable(const wpi::Twine& key) const;
+  std::shared_ptr<NetworkTable> GetSubTable(std::string_view key) const;
 
   /**
    * Determines whether the given key is in this table.
@@ -179,7 +179,7 @@ class NetworkTable final {
    * @param key the key to search for
    * @return true if the table as a value assigned to the given key
    */
-  bool ContainsKey(const wpi::Twine& key) const;
+  bool ContainsKey(std::string_view key) const;
 
   /**
    * Determines whether there exists a non-empty subtable for this key
@@ -189,7 +189,7 @@ class NetworkTable final {
    * @return true if there is a subtable with the key which contains at least
    * one key/subtable of its own
    */
-  bool ContainsSubTable(const wpi::Twine& key) const;
+  bool ContainsSubTable(std::string_view key) const;
 
   /**
    * Gets all keys in the table (not including sub-tables).
@@ -211,7 +211,7 @@ class NetworkTable final {
    *
    * @param key the key to make persistent
    */
-  void SetPersistent(wpi::StringRef key);
+  void SetPersistent(std::string_view key);
 
   /**
    * Stop making a key's value persistent through program restarts.
@@ -219,7 +219,7 @@ class NetworkTable final {
    *
    * @param key the key name
    */
-  void ClearPersistent(wpi::StringRef key);
+  void ClearPersistent(std::string_view key);
 
   /**
    * Returns whether the value is persistent through program restarts.
@@ -227,7 +227,7 @@ class NetworkTable final {
    *
    * @param key the key name
    */
-  bool IsPersistent(wpi::StringRef key) const;
+  bool IsPersistent(std::string_view key) const;
 
   /**
    * Sets flags on the specified key in this table. The key can
@@ -236,7 +236,7 @@ class NetworkTable final {
    * @param key the key name
    * @param flags the flags to set (bitmask)
    */
-  void SetFlags(wpi::StringRef key, unsigned int flags);
+  void SetFlags(std::string_view key, unsigned int flags);
 
   /**
    * Clears flags on the specified key in this table. The key can
@@ -245,7 +245,7 @@ class NetworkTable final {
    * @param key the key name
    * @param flags the flags to clear (bitmask)
    */
-  void ClearFlags(wpi::StringRef key, unsigned int flags);
+  void ClearFlags(std::string_view key, unsigned int flags);
 
   /**
    * Returns the flags for the specified key.
@@ -253,14 +253,14 @@ class NetworkTable final {
    * @param key the key name
    * @return the flags, or 0 if the key is not defined
    */
-  unsigned int GetFlags(wpi::StringRef key) const;
+  unsigned int GetFlags(std::string_view key) const;
 
   /**
    * Deletes the specified key in this table.
    *
    * @param key the key name
    */
-  void Delete(const wpi::Twine& key);
+  void Delete(std::string_view key);
 
   /**
    * Put a number in the table
@@ -269,7 +269,7 @@ class NetworkTable final {
    * @param value the value that will be assigned
    * @return False if the table key already exists with a different type
    */
-  bool PutNumber(wpi::StringRef key, double value);
+  bool PutNumber(std::string_view key, double value);
 
   /**
    * Gets the current value in the table, setting it if it does not exist.
@@ -278,7 +278,7 @@ class NetworkTable final {
    * @param defaultValue the default value to set if key doesn't exist.
    * @returns False if the table key exists with a different type
    */
-  bool SetDefaultNumber(wpi::StringRef key, double defaultValue);
+  bool SetDefaultNumber(std::string_view key, double defaultValue);
 
   /**
    * Gets the number associated with the given name.
@@ -288,7 +288,7 @@ class NetworkTable final {
    * @return the value associated with the given key or the given default value
    * if there is no value associated with the key
    */
-  double GetNumber(wpi::StringRef key, double defaultValue) const;
+  double GetNumber(std::string_view key, double defaultValue) const;
 
   /**
    * Put a string in the table
@@ -297,7 +297,7 @@ class NetworkTable final {
    * @param value the value that will be assigned
    * @return False if the table key already exists with a different type
    */
-  bool PutString(wpi::StringRef key, wpi::StringRef value);
+  bool PutString(std::string_view key, std::string_view value);
 
   /**
    * Gets the current value in the table, setting it if it does not exist.
@@ -306,7 +306,7 @@ class NetworkTable final {
    * @param defaultValue the default value to set if key doesn't exist.
    * @returns False if the table key exists with a different type
    */
-  bool SetDefaultString(wpi::StringRef key, wpi::StringRef defaultValue);
+  bool SetDefaultString(std::string_view key, std::string_view defaultValue);
 
   /**
    * Gets the string associated with the given name. If the key does not
@@ -317,7 +317,8 @@ class NetworkTable final {
    * @return the value associated with the given key or the given default value
    * if there is no value associated with the key
    */
-  std::string GetString(wpi::StringRef key, wpi::StringRef defaultValue) const;
+  std::string GetString(std::string_view key,
+                        std::string_view defaultValue) const;
 
   /**
    * Put a boolean in the table
@@ -326,7 +327,7 @@ class NetworkTable final {
    * @param value the value that will be assigned
    * @return False if the table key already exists with a different type
    */
-  bool PutBoolean(wpi::StringRef key, bool value);
+  bool PutBoolean(std::string_view key, bool value);
 
   /**
    * Gets the current value in the table, setting it if it does not exist.
@@ -335,7 +336,7 @@ class NetworkTable final {
    * @param defaultValue the default value to set if key doesn't exist.
    * @returns False if the table key exists with a different type
    */
-  bool SetDefaultBoolean(wpi::StringRef key, bool defaultValue);
+  bool SetDefaultBoolean(std::string_view key, bool defaultValue);
 
   /**
    * Gets the boolean associated with the given name. If the key does not
@@ -346,7 +347,7 @@ class NetworkTable final {
    * @return the value associated with the given key or the given default value
    * if there is no value associated with the key
    */
-  bool GetBoolean(wpi::StringRef key, bool defaultValue) const;
+  bool GetBoolean(std::string_view key, bool defaultValue) const;
 
   /**
    * Put a boolean array in the table
@@ -359,7 +360,7 @@ class NetworkTable final {
    *       std::vector<bool> is special-cased in C++.  0 is false, any
    *       non-zero value is true.
    */
-  bool PutBooleanArray(wpi::StringRef key, wpi::ArrayRef<int> value);
+  bool PutBooleanArray(std::string_view key, wpi::ArrayRef<int> value);
 
   /**
    * Gets the current value in the table, setting it if it does not exist.
@@ -368,7 +369,7 @@ class NetworkTable final {
    * @param defaultValue the default value to set if key doesn't exist.
    * @return False if the table key exists with a different type
    */
-  bool SetDefaultBooleanArray(wpi::StringRef key,
+  bool SetDefaultBooleanArray(std::string_view key,
                               wpi::ArrayRef<int> defaultValue);
 
   /**
@@ -387,7 +388,7 @@ class NetworkTable final {
    *       because std::vector<bool> is special-cased in C++.  0 is false, any
    *       non-zero value is true.
    */
-  std::vector<int> GetBooleanArray(wpi::StringRef key,
+  std::vector<int> GetBooleanArray(std::string_view key,
                                    wpi::ArrayRef<int> defaultValue) const;
 
   /**
@@ -397,7 +398,7 @@ class NetworkTable final {
    * @param value the value that will be assigned
    * @return False if the table key already exists with a different type
    */
-  bool PutNumberArray(wpi::StringRef key, wpi::ArrayRef<double> value);
+  bool PutNumberArray(std::string_view key, wpi::ArrayRef<double> value);
 
   /**
    * Gets the current value in the table, setting it if it does not exist.
@@ -406,7 +407,7 @@ class NetworkTable final {
    * @param defaultValue the default value to set if key doesn't exist.
    * @returns False if the table key exists with a different type
    */
-  bool SetDefaultNumberArray(wpi::StringRef key,
+  bool SetDefaultNumberArray(std::string_view key,
                              wpi::ArrayRef<double> defaultValue);
 
   /**
@@ -421,7 +422,7 @@ class NetworkTable final {
    * @note This makes a copy of the array.  If the overhead of this is a
    *       concern, use GetValue() instead.
    */
-  std::vector<double> GetNumberArray(wpi::StringRef key,
+  std::vector<double> GetNumberArray(std::string_view key,
                                      wpi::ArrayRef<double> defaultValue) const;
 
   /**
@@ -431,7 +432,7 @@ class NetworkTable final {
    * @param value the value that will be assigned
    * @return False if the table key already exists with a different type
    */
-  bool PutStringArray(wpi::StringRef key, wpi::ArrayRef<std::string> value);
+  bool PutStringArray(std::string_view key, wpi::ArrayRef<std::string> value);
 
   /**
    * Gets the current value in the table, setting it if it does not exist.
@@ -440,7 +441,7 @@ class NetworkTable final {
    * @param defaultValue the default value to set if key doesn't exist.
    * @returns False if the table key exists with a different type
    */
-  bool SetDefaultStringArray(wpi::StringRef key,
+  bool SetDefaultStringArray(std::string_view key,
                              wpi::ArrayRef<std::string> defaultValue);
 
   /**
@@ -456,7 +457,7 @@ class NetworkTable final {
    *       concern, use GetValue() instead.
    */
   std::vector<std::string> GetStringArray(
-      wpi::StringRef key, wpi::ArrayRef<std::string> defaultValue) const;
+      std::string_view key, wpi::ArrayRef<std::string> defaultValue) const;
 
   /**
    * Put a raw value (byte array) in the table
@@ -465,7 +466,7 @@ class NetworkTable final {
    * @param value the value that will be assigned
    * @return False if the table key already exists with a different type
    */
-  bool PutRaw(wpi::StringRef key, wpi::StringRef value);
+  bool PutRaw(std::string_view key, std::string_view value);
 
   /**
    * Gets the current value in the table, setting it if it does not exist.
@@ -474,7 +475,7 @@ class NetworkTable final {
    * @param defaultValue the default value to set if key doesn't exist.
    * @return False if the table key exists with a different type
    */
-  bool SetDefaultRaw(wpi::StringRef key, wpi::StringRef defaultValue);
+  bool SetDefaultRaw(std::string_view key, std::string_view defaultValue);
 
   /**
    * Returns the raw value (byte array) the key maps to. If the key does not
@@ -488,7 +489,7 @@ class NetworkTable final {
    * @note This makes a copy of the raw contents.  If the overhead of this is a
    *       concern, use GetValue() instead.
    */
-  std::string GetRaw(wpi::StringRef key, wpi::StringRef defaultValue) const;
+  std::string GetRaw(std::string_view key, std::string_view defaultValue) const;
 
   /**
    * Put a value in the table
@@ -497,7 +498,7 @@ class NetworkTable final {
    * @param value the value that will be assigned
    * @return False if the table key already exists with a different type
    */
-  bool PutValue(const wpi::Twine& key, std::shared_ptr<Value> value);
+  bool PutValue(std::string_view key, std::shared_ptr<Value> value);
 
   /**
    * Gets the current value in the table, setting it if it does not exist.
@@ -506,7 +507,7 @@ class NetworkTable final {
    * @param defaultValue the default value to set if key doesn't exist.
    * @return False if the table key exists with a different type
    */
-  bool SetDefaultValue(const wpi::Twine& key,
+  bool SetDefaultValue(std::string_view key,
                        std::shared_ptr<Value> defaultValue);
 
   /**
@@ -516,14 +517,14 @@ class NetworkTable final {
    * @return the value associated with the given key, or nullptr if the key
    * does not exist
    */
-  std::shared_ptr<Value> GetValue(const wpi::Twine& key) const;
+  std::shared_ptr<Value> GetValue(std::string_view key) const;
 
   /**
    * Gets the full path of this table.  Does not include the trailing "/".
    *
    * @return The path (e.g "", "/foo").
    */
-  wpi::StringRef GetPath() const;
+  std::string_view GetPath() const;
 
   /**
    * Save table values to a file.  The file format used is identical to
@@ -532,7 +533,7 @@ class NetworkTable final {
    * @param filename  filename
    * @return error string, or nullptr if successful
    */
-  const char* SaveEntries(const wpi::Twine& filename) const;
+  const char* SaveEntries(std::string_view filename) const;
 
   /**
    * Load table values from a file.  The file format used is identical to
@@ -543,7 +544,7 @@ class NetworkTable final {
    * @return error string, or nullptr if successful
    */
   const char* LoadEntries(
-      const wpi::Twine& filename,
+      std::string_view filename,
       std::function<void(size_t line, const char* msg)> warn);
 };
 
diff --git a/ntcore/src/main/native/include/networktables/NetworkTableEntry.h b/ntcore/src/main/native/include/networktables/NetworkTableEntry.h
index 92c1f352f1..7774fa2157 100644
--- a/ntcore/src/main/native/include/networktables/NetworkTableEntry.h
+++ b/ntcore/src/main/native/include/networktables/NetworkTableEntry.h
@@ -10,11 +10,9 @@
 #include <initializer_list>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <vector>
 
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
-
 #include "networktables/NetworkTableType.h"
 #include "networktables/NetworkTableValue.h"
 #include "networktables/RpcCall.h"
@@ -143,7 +141,7 @@ class NetworkTableEntry final {
    * @param defaultValue the value to be returned if no value is found
    * @return the entry's value or the given default value
    */
-  std::string GetString(wpi::StringRef defaultValue) const;
+  std::string GetString(std::string_view defaultValue) const;
 
   /**
    * Gets the entry's value as a raw. If the entry does not exist or is of
@@ -152,7 +150,7 @@ class NetworkTableEntry final {
    * @param defaultValue the value to be returned if no value is found
    * @return the entry's value or the given default value
    */
-  std::string GetRaw(wpi::StringRef defaultValue) const;
+  std::string GetRaw(std::string_view defaultValue) const;
 
   /**
    * Gets the entry's value as a boolean array. If the entry does not exist
@@ -268,7 +266,7 @@ class NetworkTableEntry final {
    * @param defaultValue the default value to set
    * @return False if the entry exists with a different type
    */
-  bool SetDefaultString(const wpi::Twine& defaultValue);
+  bool SetDefaultString(std::string_view defaultValue);
 
   /**
    * Sets the entry's value if it does not exist.
@@ -276,7 +274,7 @@ class NetworkTableEntry final {
    * @param defaultValue the default value to set
    * @return False if the entry exists with a different type
    */
-  bool SetDefaultRaw(wpi::StringRef defaultValue);
+  bool SetDefaultRaw(std::string_view defaultValue);
 
   /**
    * Sets the entry's value if it does not exist.
@@ -356,7 +354,7 @@ class NetworkTableEntry final {
    * @param value the value to set
    * @return False if the entry exists with a different type
    */
-  bool SetString(const wpi::Twine& value);
+  bool SetString(std::string_view value);
 
   /**
    * Sets the entry's value.
@@ -364,7 +362,7 @@ class NetworkTableEntry final {
    * @param value the value to set
    * @return False if the entry exists with a different type
    */
-  bool SetRaw(wpi::StringRef value);
+  bool SetRaw(std::string_view value);
 
   /**
    * Sets the entry's value.
@@ -460,7 +458,7 @@ class NetworkTableEntry final {
    *
    * @param value the value to set
    */
-  void ForceSetString(const wpi::Twine& value);
+  void ForceSetString(std::string_view value);
 
   /**
    * Sets the entry's value.  If the value is of different type, the type is
@@ -468,7 +466,7 @@ class NetworkTableEntry final {
    *
    * @param value the value to set
    */
-  void ForceSetRaw(wpi::StringRef value);
+  void ForceSetRaw(std::string_view value);
 
   /**
    * Sets the entry's value.  If the value is of different type, the type is
@@ -596,7 +594,7 @@ class NetworkTableEntry final {
    * @param params      parameter
    * @return RPC call object.
    */
-  RpcCall CallRpc(wpi::StringRef params);
+  RpcCall CallRpc(std::string_view params);
 
   /**
    * Add a listener for changes to this entry.
diff --git a/ntcore/src/main/native/include/networktables/NetworkTableEntry.inc b/ntcore/src/main/native/include/networktables/NetworkTableEntry.inc
index ba1628e4d6..00082b3961 100644
--- a/ntcore/src/main/native/include/networktables/NetworkTableEntry.inc
+++ b/ntcore/src/main/native/include/networktables/NetworkTableEntry.inc
@@ -7,6 +7,7 @@
 
 #include <memory>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include "networktables/NetworkTableEntry.h"
@@ -67,21 +68,21 @@ inline double NetworkTableEntry::GetDouble(double defaultValue) const {
 }
 
 inline std::string NetworkTableEntry::GetString(
-    wpi::StringRef defaultValue) const {
+    std::string_view defaultValue) const {
   auto value = GetEntryValue(m_handle);
   if (!value || value->type() != NT_STRING) {
-    return defaultValue;
+    return std::string{defaultValue};
   }
-  return value->GetString();
+  return std::string{value->GetString()};
 }
 
 inline std::string NetworkTableEntry::GetRaw(
-    wpi::StringRef defaultValue) const {
+    std::string_view defaultValue) const {
   auto value = GetEntryValue(m_handle);
   if (!value || value->type() != NT_RAW) {
-    return defaultValue;
+    return std::string{defaultValue};
   }
-  return value->GetRaw();
+  return std::string{value->GetRaw()};
 }
 
 inline std::vector<int> NetworkTableEntry::GetBooleanArray(
@@ -141,12 +142,11 @@ inline bool NetworkTableEntry::SetDefaultDouble(double defaultValue) {
   return SetDefaultEntryValue(m_handle, Value::MakeDouble(defaultValue));
 }
 
-inline bool NetworkTableEntry::SetDefaultString(
-    const wpi::Twine& defaultValue) {
+inline bool NetworkTableEntry::SetDefaultString(std::string_view defaultValue) {
   return SetDefaultEntryValue(m_handle, Value::MakeString(defaultValue));
 }
 
-inline bool NetworkTableEntry::SetDefaultRaw(wpi::StringRef defaultValue) {
+inline bool NetworkTableEntry::SetDefaultRaw(std::string_view defaultValue) {
   return SetDefaultEntryValue(m_handle, Value::MakeRaw(defaultValue));
 }
 
@@ -192,11 +192,11 @@ inline bool NetworkTableEntry::SetDouble(double value) {
   return SetEntryValue(m_handle, Value::MakeDouble(value));
 }
 
-inline bool NetworkTableEntry::SetString(const wpi::Twine& value) {
+inline bool NetworkTableEntry::SetString(std::string_view value) {
   return SetEntryValue(m_handle, Value::MakeString(value));
 }
 
-inline bool NetworkTableEntry::SetRaw(wpi::StringRef value) {
+inline bool NetworkTableEntry::SetRaw(std::string_view value) {
   return SetEntryValue(m_handle, Value::MakeRaw(value));
 }
 
@@ -249,11 +249,11 @@ inline void NetworkTableEntry::ForceSetDouble(double value) {
   SetEntryTypeValue(m_handle, Value::MakeDouble(value));
 }
 
-inline void NetworkTableEntry::ForceSetString(const wpi::Twine& value) {
+inline void NetworkTableEntry::ForceSetString(std::string_view value) {
   SetEntryTypeValue(m_handle, Value::MakeString(value));
 }
 
-inline void NetworkTableEntry::ForceSetRaw(wpi::StringRef value) {
+inline void NetworkTableEntry::ForceSetRaw(std::string_view value) {
   SetEntryTypeValue(m_handle, Value::MakeRaw(value));
 }
 
@@ -321,10 +321,10 @@ inline void NetworkTableEntry::Delete() {
 
 inline void NetworkTableEntry::CreateRpc(
     std::function<void(const RpcAnswer& answer)> callback) {
-  ::nt::CreateRpc(m_handle, wpi::StringRef("\0", 1), callback);
+  ::nt::CreateRpc(m_handle, std::string_view("\0", 1), callback);
 }
 
-inline RpcCall NetworkTableEntry::CallRpc(wpi::StringRef params) {
+inline RpcCall NetworkTableEntry::CallRpc(std::string_view params) {
   return RpcCall{m_handle, ::nt::CallRpc(m_handle, params)};
 }
 
diff --git a/ntcore/src/main/native/include/networktables/NetworkTableInstance.h b/ntcore/src/main/native/include/networktables/NetworkTableInstance.h
index 89c4fe038e..3f7f247ac7 100644
--- a/ntcore/src/main/native/include/networktables/NetworkTableInstance.h
+++ b/ntcore/src/main/native/include/networktables/NetworkTableInstance.h
@@ -8,12 +8,11 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
 #include <wpi/ArrayRef.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 
 #include "networktables/NetworkTable.h"
 #include "networktables/NetworkTableEntry.h"
@@ -131,7 +130,7 @@ class NetworkTableInstance final {
    * @param name Key
    * @return Network table entry.
    */
-  NetworkTableEntry GetEntry(const wpi::Twine& name);
+  NetworkTableEntry GetEntry(std::string_view name);
 
   /**
    * Get entries starting with the given prefix.
@@ -144,7 +143,7 @@ class NetworkTableInstance final {
    * @param types bitmask of types; 0 is treated as a "don't care"
    * @return Array of entries.
    */
-  std::vector<NetworkTableEntry> GetEntries(const wpi::Twine& prefix,
+  std::vector<NetworkTableEntry> GetEntries(std::string_view prefix,
                                             unsigned int types);
 
   /**
@@ -158,7 +157,7 @@ class NetworkTableInstance final {
    * @param types bitmask of types; 0 is treated as a "don't care"
    * @return Array of entry information.
    */
-  std::vector<EntryInfo> GetEntryInfo(const wpi::Twine& prefix,
+  std::vector<EntryInfo> GetEntryInfo(std::string_view prefix,
                                       unsigned int types) const;
 
   /**
@@ -167,7 +166,7 @@ class NetworkTableInstance final {
    * @param key the key name
    * @return The network table
    */
-  std::shared_ptr<NetworkTable> GetTable(const wpi::Twine& key) const;
+  std::shared_ptr<NetworkTable> GetTable(std::string_view key) const;
 
   /**
    * Deletes ALL keys in ALL subtables (except persistent values).
@@ -189,7 +188,7 @@ class NetworkTableInstance final {
    * @return Listener handle
    */
   NT_EntryListener AddEntryListener(
-      const wpi::Twine& prefix,
+      std::string_view prefix,
       std::function<void(const EntryNotification& event)> callback,
       unsigned int flags) const;
 
@@ -283,7 +282,7 @@ class NetworkTableInstance final {
    *
    * @param name      identity to advertise
    */
-  void SetNetworkIdentity(const wpi::Twine& name);
+  void SetNetworkIdentity(std::string_view name);
 
   /**
    * Get the current network mode.
@@ -314,7 +313,7 @@ class NetworkTableInstance final {
    *                          address (UTF-8 string, null terminated)
    * @param port              port to communicate over
    */
-  void StartServer(const wpi::Twine& persist_filename = "networktables.ini",
+  void StartServer(std::string_view persist_filename = "networktables.ini",
                    const char* listen_address = "",
                    unsigned int port = kDefaultPort);
 
@@ -343,7 +342,7 @@ class NetworkTableInstance final {
    * @param servers   array of server name and port pairs
    */
   void StartClient(
-      wpi::ArrayRef<std::pair<wpi::StringRef, unsigned int>> servers);
+      wpi::ArrayRef<std::pair<std::string_view, unsigned int>> servers);
 
   /**
    * Starts a client using the specified servers and port.  The
@@ -352,7 +351,7 @@ class NetworkTableInstance final {
    * @param servers   array of server names
    * @param port      port to communicate over
    */
-  void StartClient(wpi::ArrayRef<wpi::StringRef> servers,
+  void StartClient(wpi::ArrayRef<std::string_view> servers,
                    unsigned int port = kDefaultPort);
 
   /**
@@ -384,7 +383,7 @@ class NetworkTableInstance final {
    * @param servers   array of server name and port pairs
    */
   void SetServer(
-      wpi::ArrayRef<std::pair<wpi::StringRef, unsigned int>> servers);
+      wpi::ArrayRef<std::pair<std::string_view, unsigned int>> servers);
 
   /**
    * Sets server addresses and port for client (without restarting client).
@@ -393,7 +392,7 @@ class NetworkTableInstance final {
    * @param servers   array of server names
    * @param port      port to communicate over
    */
-  void SetServer(wpi::ArrayRef<wpi::StringRef> servers,
+  void SetServer(wpi::ArrayRef<std::string_view> servers,
                  unsigned int port = kDefaultPort);
 
   /**
@@ -465,7 +464,7 @@ class NetworkTableInstance final {
    * @param filename  filename
    * @return error string, or nullptr if successful
    */
-  const char* SavePersistent(const wpi::Twine& filename) const;
+  const char* SavePersistent(std::string_view filename) const;
 
   /**
    * Load persistent values from a file.  The server automatically does this
@@ -477,7 +476,7 @@ class NetworkTableInstance final {
    * @return error string, or nullptr if successful
    */
   const char* LoadPersistent(
-      const wpi::Twine& filename,
+      std::string_view filename,
       std::function<void(size_t line, const char* msg)> warn);
 
   /**
@@ -488,8 +487,8 @@ class NetworkTableInstance final {
    * @param prefix    save only keys starting with this prefix
    * @return error string, or nullptr if successful
    */
-  const char* SaveEntries(const wpi::Twine& filename,
-                          const wpi::Twine& prefix) const;
+  const char* SaveEntries(std::string_view filename,
+                          std::string_view prefix) const;
 
   /**
    * Load table values from a file.  The file format used is identical to
@@ -501,7 +500,7 @@ class NetworkTableInstance final {
    * @return error string, or nullptr if successful
    */
   const char* LoadEntries(
-      const wpi::Twine& filename, const wpi::Twine& prefix,
+      std::string_view filename, std::string_view prefix,
       std::function<void(size_t line, const char* msg)> warn);
 
   /** @} */
diff --git a/ntcore/src/main/native/include/networktables/NetworkTableInstance.inc b/ntcore/src/main/native/include/networktables/NetworkTableInstance.inc
index ea8e74f447..9bb5399d8a 100644
--- a/ntcore/src/main/native/include/networktables/NetworkTableInstance.inc
+++ b/ntcore/src/main/native/include/networktables/NetworkTableInstance.inc
@@ -5,6 +5,7 @@
 #ifndef NTCORE_NETWORKTABLES_NETWORKTABLEINSTANCE_INC_
 #define NTCORE_NETWORKTABLES_NETWORKTABLEINSTANCE_INC_
 
+#include <string_view>
 #include <utility>
 #include <vector>
 
@@ -35,13 +36,12 @@ inline NT_Inst NetworkTableInstance::GetHandle() const {
   return m_handle;
 }
 
-inline NetworkTableEntry NetworkTableInstance::GetEntry(
-    const wpi::Twine& name) {
+inline NetworkTableEntry NetworkTableInstance::GetEntry(std::string_view name) {
   return NetworkTableEntry{::nt::GetEntry(m_handle, name)};
 }
 
 inline std::vector<NetworkTableEntry> NetworkTableInstance::GetEntries(
-    const wpi::Twine& prefix, unsigned int types) {
+    std::string_view prefix, unsigned int types) {
   std::vector<NetworkTableEntry> entries;
   for (auto entry : ::nt::GetEntries(m_handle, prefix, types)) {
     entries.emplace_back(entry);
@@ -50,7 +50,7 @@ inline std::vector<NetworkTableEntry> NetworkTableInstance::GetEntries(
 }
 
 inline std::vector<EntryInfo> NetworkTableInstance::GetEntryInfo(
-    const wpi::Twine& prefix, unsigned int types) const {
+    std::string_view prefix, unsigned int types) const {
   return ::nt::GetEntryInfo(m_handle, prefix, types);
 }
 
@@ -81,7 +81,7 @@ inline bool NetworkTableInstance::WaitForRpcCallQueue(double timeout) {
   return ::nt::WaitForRpcCallQueue(m_handle, timeout);
 }
 
-inline void NetworkTableInstance::SetNetworkIdentity(const wpi::Twine& name) {
+inline void NetworkTableInstance::SetNetworkIdentity(std::string_view name) {
   ::nt::SetNetworkIdentity(m_handle, name);
 }
 
@@ -97,9 +97,9 @@ inline void NetworkTableInstance::StopLocal() {
   ::nt::StopLocal(m_handle);
 }
 
-inline void NetworkTableInstance::StartServer(
-    const wpi::Twine& persist_filename, const char* listen_address,
-    unsigned int port) {
+inline void NetworkTableInstance::StartServer(std::string_view persist_filename,
+                                              const char* listen_address,
+                                              unsigned int port) {
   ::nt::StartServer(m_handle, persist_filename, listen_address, port);
 }
 
@@ -117,7 +117,7 @@ inline void NetworkTableInstance::StartClient(const char* server_name,
 }
 
 inline void NetworkTableInstance::StartClient(
-    wpi::ArrayRef<std::pair<wpi::StringRef, unsigned int>> servers) {
+    wpi::ArrayRef<std::pair<std::string_view, unsigned int>> servers) {
   ::nt::StartClient(m_handle, servers);
 }
 
@@ -136,7 +136,7 @@ inline void NetworkTableInstance::SetServer(const char* server_name,
 }
 
 inline void NetworkTableInstance::SetServer(
-    wpi::ArrayRef<std::pair<wpi::StringRef, unsigned int>> servers) {
+    wpi::ArrayRef<std::pair<std::string_view, unsigned int>> servers) {
   ::nt::SetServer(m_handle, servers);
 }
 
@@ -171,23 +171,23 @@ inline bool NetworkTableInstance::IsConnected() const {
 }
 
 inline const char* NetworkTableInstance::SavePersistent(
-    const wpi::Twine& filename) const {
+    std::string_view filename) const {
   return ::nt::SavePersistent(m_handle, filename);
 }
 
 inline const char* NetworkTableInstance::LoadPersistent(
-    const wpi::Twine& filename,
+    std::string_view filename,
     std::function<void(size_t line, const char* msg)> warn) {
   return ::nt::LoadPersistent(m_handle, filename, warn);
 }
 
 inline const char* NetworkTableInstance::SaveEntries(
-    const wpi::Twine& filename, const wpi::Twine& prefix) const {
+    std::string_view filename, std::string_view prefix) const {
   return ::nt::SaveEntries(m_handle, filename, prefix);
 }
 
 inline const char* NetworkTableInstance::LoadEntries(
-    const wpi::Twine& filename, const wpi::Twine& prefix,
+    std::string_view filename, std::string_view prefix,
     std::function<void(size_t line, const char* msg)> warn) {
   return ::nt::LoadEntries(m_handle, filename, prefix, warn);
 }
diff --git a/ntcore/src/main/native/include/networktables/NetworkTableValue.h b/ntcore/src/main/native/include/networktables/NetworkTableValue.h
index 014bc326cd..acc51ad2b9 100644
--- a/ntcore/src/main/native/include/networktables/NetworkTableValue.h
+++ b/ntcore/src/main/native/include/networktables/NetworkTableValue.h
@@ -11,13 +11,12 @@
 #include <initializer_list>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <type_traits>
 #include <utility>
 #include <vector>
 
 #include <wpi/ArrayRef.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 
 #include "ntcore_c.h"
 
@@ -163,7 +162,7 @@ class Value final {
    *
    * @return The string value.
    */
-  wpi::StringRef GetString() const {
+  std::string_view GetString() const {
     assert(m_val.type == NT_STRING);
     return m_string;
   }
@@ -173,7 +172,7 @@ class Value final {
    *
    * @return The raw value.
    */
-  wpi::StringRef GetRaw() const {
+  std::string_view GetRaw() const {
     assert(m_val.type == NT_RAW);
     return m_string;
   }
@@ -183,7 +182,7 @@ class Value final {
    *
    * @return The rpc definition value.
    */
-  wpi::StringRef GetRpc() const {
+  std::string_view GetRpc() const {
     assert(m_val.type == NT_RPC);
     return m_string;
   }
@@ -263,10 +262,10 @@ class Value final {
    *             time)
    * @return The entry value
    */
-  static std::shared_ptr<Value> MakeString(const wpi::Twine& value,
+  static std::shared_ptr<Value> MakeString(std::string_view value,
                                            uint64_t time = 0) {
     auto val = std::make_shared<Value>(NT_STRING, time, private_init());
-    val->m_string = value.str();
+    val->m_string = value;
     val->m_val.data.v_string.str = const_cast<char*>(val->m_string.c_str());
     val->m_val.data.v_string.len = val->m_string.size();
     return val;
@@ -298,7 +297,7 @@ class Value final {
    *             time)
    * @return The entry value
    */
-  static std::shared_ptr<Value> MakeRaw(wpi::StringRef value,
+  static std::shared_ptr<Value> MakeRaw(std::string_view value,
                                         uint64_t time = 0) {
     auto val = std::make_shared<Value>(NT_RAW, time, private_init());
     val->m_string = value;
@@ -333,7 +332,7 @@ class Value final {
    *             time)
    * @return The entry value
    */
-  static std::shared_ptr<Value> MakeRpc(wpi::StringRef value,
+  static std::shared_ptr<Value> MakeRpc(std::string_view value,
                                         uint64_t time = 0) {
     auto val = std::make_shared<Value>(NT_RPC, time, private_init());
     val->m_string = value;
diff --git a/ntcore/src/main/native/include/networktables/TableEntryListener.h b/ntcore/src/main/native/include/networktables/TableEntryListener.h
index 4930bf0056..180234f386 100644
--- a/ntcore/src/main/native/include/networktables/TableEntryListener.h
+++ b/ntcore/src/main/native/include/networktables/TableEntryListener.h
@@ -7,8 +7,7 @@
 
 #include <functional>
 #include <memory>
-
-#include <wpi/StringRef.h>
+#include <string_view>
 
 namespace nt {
 
@@ -30,10 +29,9 @@ class Value;
  *
  * @ingroup ntcore_cpp_api
  */
-typedef std::function<void(NetworkTable* table, wpi::StringRef name,
-                           NetworkTableEntry entry,
-                           std::shared_ptr<Value> value, int flags)>
-    TableEntryListener;
+using TableEntryListener = std::function<void(
+    NetworkTable* table, std::string_view name, NetworkTableEntry entry,
+    std::shared_ptr<Value> value, int flags)>;
 
 }  // namespace nt
 
diff --git a/ntcore/src/main/native/include/networktables/TableListener.h b/ntcore/src/main/native/include/networktables/TableListener.h
index 3e8f8c70cd..cc1113ea61 100644
--- a/ntcore/src/main/native/include/networktables/TableListener.h
+++ b/ntcore/src/main/native/include/networktables/TableListener.h
@@ -7,8 +7,7 @@
 
 #include <functional>
 #include <memory>
-
-#include <wpi/StringRef.h>
+#include <string_view>
 
 namespace nt {
 
@@ -25,9 +24,9 @@ class NetworkTable;
  *
  * @ingroup ntcore_cpp_api
  */
-typedef std::function<void(NetworkTable* parent, wpi::StringRef name,
-                           std::shared_ptr<NetworkTable> table)>
-    TableListener;
+using TableListener =
+    std::function<void(NetworkTable* parent, std::string_view name,
+                       std::shared_ptr<NetworkTable> table)>;
 
 }  // namespace nt
 
diff --git a/ntcore/src/main/native/include/ntcore_cpp.h b/ntcore/src/main/native/include/ntcore_cpp.h
index 74bc1e8ac6..2bc517a6d7 100644
--- a/ntcore/src/main/native/include/ntcore_cpp.h
+++ b/ntcore/src/main/native/include/ntcore_cpp.h
@@ -11,13 +11,12 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <thread>
 #include <utility>
 #include <vector>
 
 #include <wpi/ArrayRef.h>
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
 
 #include "networktables/NetworkTableValue.h"
 
@@ -98,7 +97,7 @@ struct ConnectionInfo {
 /** NetworkTables RPC Version 1 Definition Parameter */
 struct RpcParamDef {
   RpcParamDef() = default;
-  RpcParamDef(wpi::StringRef name_, std::shared_ptr<Value> def_value_)
+  RpcParamDef(std::string_view name_, std::shared_ptr<Value> def_value_)
       : name(name_), def_value(std::move(def_value_)) {}
 
   std::string name;
@@ -108,7 +107,7 @@ struct RpcParamDef {
 /** NetworkTables RPC Version 1 Definition Result */
 struct RpcResultDef {
   RpcResultDef() = default;
-  RpcResultDef(wpi::StringRef name_, NT_Type type_)
+  RpcResultDef(std::string_view name_, NT_Type type_)
       : name(name_), type(type_) {}
 
   std::string name;
@@ -127,8 +126,8 @@ struct RpcDefinition {
 class RpcAnswer {
  public:
   RpcAnswer() = default;
-  RpcAnswer(NT_Entry entry_, NT_RpcCall call_, wpi::StringRef name_,
-            wpi::StringRef params_, ConnectionInfo conn_)
+  RpcAnswer(NT_Entry entry_, NT_RpcCall call_, std::string_view name_,
+            std::string_view params_, ConnectionInfo conn_)
       : entry(entry_),
         call(call_),
         name(name_),
@@ -161,7 +160,7 @@ class RpcAnswer {
    * @param result  result raw data that will be provided to remote caller
    * @return True if posting the response is valid, otherwise false
    */
-  bool PostResponse(wpi::StringRef result) const;
+  bool PostResponse(std::string_view result) const;
 
   friend void swap(RpcAnswer& first, RpcAnswer& second) {
     using std::swap;
@@ -178,7 +177,7 @@ class EntryNotification {
  public:
   EntryNotification() = default;
   EntryNotification(NT_EntryListener listener_, NT_Entry entry_,
-                    wpi::StringRef name_, std::shared_ptr<Value> value_,
+                    std::string_view name_, std::shared_ptr<Value> value_,
                     unsigned int flags_)
       : listener(listener_),
         entry(entry_),
@@ -245,7 +244,7 @@ class LogMessage {
  public:
   LogMessage() = default;
   LogMessage(NT_Logger logger_, unsigned int level_, const char* filename_,
-             unsigned int line_, wpi::StringRef message_)
+             unsigned int line_, std::string_view message_)
       : logger(logger_),
         level(level_),
         filename(filename_),
@@ -327,7 +326,7 @@ NT_Inst GetInstanceFromHandle(NT_Handle handle);
  * @param name      entry name (UTF-8 string)
  * @return entry handle
  */
-NT_Entry GetEntry(NT_Inst inst, const wpi::Twine& name);
+NT_Entry GetEntry(NT_Inst inst, std::string_view name);
 
 /**
  * Get Entry Handles.
@@ -343,7 +342,7 @@ NT_Entry GetEntry(NT_Inst inst, const wpi::Twine& name);
  *                      as a "don't care"
  * @return Array of entry handles.
  */
-std::vector<NT_Entry> GetEntries(NT_Inst inst, const wpi::Twine& prefix,
+std::vector<NT_Entry> GetEntries(NT_Inst inst, std::string_view prefix,
                                  unsigned int types);
 
 /**
@@ -484,7 +483,7 @@ void DeleteAllEntries(NT_Inst inst);
  *                      as a "don't care"
  * @return Array of entry information.
  */
-std::vector<EntryInfo> GetEntryInfo(NT_Inst inst, const wpi::Twine& prefix,
+std::vector<EntryInfo> GetEntryInfo(NT_Inst inst, std::string_view prefix,
                                     unsigned int types);
 
 /**
@@ -516,9 +515,9 @@ EntryInfo GetEntryInfo(NT_Entry entry);
  * @param flags           update flags; for example, NT_NOTIFY_NEW if the key
  *                        did not previously exist
  */
-typedef std::function<void(NT_EntryListener entry_listener, wpi::StringRef name,
-                           std::shared_ptr<Value> value, unsigned int flags)>
-    EntryListenerCallback;
+using EntryListenerCallback =
+    std::function<void(NT_EntryListener entry_listener, std::string_view name,
+                       std::shared_ptr<Value> value, unsigned int flags)>;
 
 /**
  * Add a listener for all entries starting with a certain prefix.
@@ -530,7 +529,7 @@ typedef std::function<void(NT_EntryListener entry_listener, wpi::StringRef name,
  * @return Listener handle
  */
 NT_EntryListener AddEntryListener(
-    NT_Inst inst, const wpi::Twine& prefix,
+    NT_Inst inst, std::string_view prefix,
     std::function<void(const EntryNotification& event)> callback,
     unsigned int flags);
 
@@ -578,7 +577,7 @@ void DestroyEntryListenerPoller(NT_EntryListenerPoller poller);
  * @return Listener handle
  */
 NT_EntryListener AddPolledEntryListener(NT_EntryListenerPoller poller,
-                                        const wpi::Twine& prefix,
+                                        std::string_view prefix,
                                         unsigned int flags);
 
 /**
@@ -787,7 +786,7 @@ bool WaitForConnectionListenerQueue(NT_Inst inst, double timeout);
  * @param callback  callback function; note the callback function must call
  *                  PostRpcResponse() to provide a response to the call
  */
-void CreateRpc(NT_Entry entry, wpi::StringRef def,
+void CreateRpc(NT_Entry entry, std::string_view def,
                std::function<void(const RpcAnswer& answer)> callback);
 
 /**
@@ -820,7 +819,7 @@ void DestroyRpcCallPoller(NT_RpcCallPoller poller);
  * @param def       RPC definition
  * @param poller    poller handle
  */
-void CreatePolledRpc(NT_Entry entry, wpi::StringRef def,
+void CreatePolledRpc(NT_Entry entry, std::string_view def,
                      NT_RpcCallPoller poller);
 
 /**
@@ -884,7 +883,7 @@ bool WaitForRpcCallQueue(NT_Inst inst, double timeout);
  * @param result      result raw data that will be provided to remote caller
  * @return            true if the response was posted, otherwise false
  */
-bool PostRpcResponse(NT_Entry entry, NT_RpcCall call, wpi::StringRef result);
+bool PostRpcResponse(NT_Entry entry, NT_RpcCall call, std::string_view result);
 
 /**
  * Call a RPC function.  May be used on either the client or server.
@@ -897,7 +896,7 @@ bool PostRpcResponse(NT_Entry entry, NT_RpcCall call, wpi::StringRef result);
  * @return RPC call handle (for use with GetRpcResult() or
  *         CancelRpcResult()).
  */
-NT_RpcCall CallRpc(NT_Entry entry, wpi::StringRef params);
+NT_RpcCall CallRpc(NT_Entry entry, std::string_view params);
 
 /**
  * Get the result (return value) of a RPC call.  This function blocks until
@@ -948,7 +947,7 @@ std::string PackRpcDefinition(const RpcDefinition& def);
  * @param def         RPC version 1 definition (output)
  * @return True if successfully unpacked, false otherwise.
  */
-bool UnpackRpcDefinition(wpi::StringRef packed, RpcDefinition* def);
+bool UnpackRpcDefinition(std::string_view packed, RpcDefinition* def);
 
 /**
  * Pack RPC values as required for RPC version 1 definition messages.
@@ -966,7 +965,7 @@ std::string PackRpcValues(wpi::ArrayRef<std::shared_ptr<Value>> values);
  * @return Array of values.
  */
 std::vector<std::shared_ptr<Value>> UnpackRpcValues(
-    wpi::StringRef packed, wpi::ArrayRef<NT_Type> types);
+    std::string_view packed, wpi::ArrayRef<NT_Type> types);
 
 /** @} */
 
@@ -983,7 +982,7 @@ std::vector<std::shared_ptr<Value>> UnpackRpcValues(
  * @param inst      instance handle
  * @param name      identity to advertise
  */
-void SetNetworkIdentity(NT_Inst inst, const wpi::Twine& name);
+void SetNetworkIdentity(NT_Inst inst, std::string_view name);
 
 /**
  * Get the current network mode.
@@ -1016,7 +1015,7 @@ void StopLocal(NT_Inst inst);
  *                          address. (UTF-8 string, null terminated)
  * @param port              port to communicate over.
  */
-void StartServer(NT_Inst inst, const wpi::Twine& persist_filename,
+void StartServer(NT_Inst inst, std::string_view persist_filename,
                  const char* listen_address, unsigned int port);
 
 /**
@@ -1051,7 +1050,7 @@ void StartClient(NT_Inst inst, const char* server_name, unsigned int port);
  */
 void StartClient(
     NT_Inst inst,
-    wpi::ArrayRef<std::pair<wpi::StringRef, unsigned int>> servers);
+    wpi::ArrayRef<std::pair<std::string_view, unsigned int>> servers);
 
 /**
  * Starts a client using commonly known robot addresses for the specified
@@ -1086,8 +1085,9 @@ void SetServer(NT_Inst inst, const char* server_name, unsigned int port);
  * @param inst      instance handle
  * @param servers   array of server name and port pairs
  */
-void SetServer(NT_Inst inst,
-               wpi::ArrayRef<std::pair<wpi::StringRef, unsigned int>> servers);
+void SetServer(
+    NT_Inst inst,
+    wpi::ArrayRef<std::pair<std::string_view, unsigned int>> servers);
 
 /**
  * Sets server addresses and port for client (without restarting client).
@@ -1173,7 +1173,7 @@ bool IsConnected(NT_Inst inst);
  * @param filename  filename
  * @return error string, or nullptr if successful
  */
-const char* SavePersistent(NT_Inst inst, const wpi::Twine& filename);
+const char* SavePersistent(NT_Inst inst, std::string_view filename);
 
 /**
  * Load persistent values from a file.  The server automatically does this
@@ -1186,7 +1186,7 @@ const char* SavePersistent(NT_Inst inst, const wpi::Twine& filename);
  * @return error string, or nullptr if successful
  */
 const char* LoadPersistent(
-    NT_Inst inst, const wpi::Twine& filename,
+    NT_Inst inst, std::string_view filename,
     std::function<void(size_t line, const char* msg)> warn);
 
 /**
@@ -1198,8 +1198,8 @@ const char* LoadPersistent(
  * @param prefix    save only keys starting with this prefix
  * @return error string, or nullptr if successful
  */
-const char* SaveEntries(NT_Inst inst, const wpi::Twine& filename,
-                        const wpi::Twine& prefix);
+const char* SaveEntries(NT_Inst inst, std::string_view filename,
+                        std::string_view prefix);
 
 /**
  * Load table values from a file.  The file format used is identical to
@@ -1211,8 +1211,8 @@ const char* SaveEntries(NT_Inst inst, const wpi::Twine& filename,
  * @param warn      callback function for warnings
  * @return error string, or nullptr if successful
  */
-const char* LoadEntries(NT_Inst inst, const wpi::Twine& filename,
-                        const wpi::Twine& prefix,
+const char* LoadEntries(NT_Inst inst, std::string_view filename,
+                        std::string_view prefix,
                         std::function<void(size_t line, const char* msg)> warn);
 
 /** @} */
@@ -1339,7 +1339,7 @@ bool WaitForLoggerQueue(NT_Inst inst, double timeout);
 /** @} */
 /** @} */
 
-inline bool RpcAnswer::PostResponse(wpi::StringRef result) const {
+inline bool RpcAnswer::PostResponse(std::string_view result) const {
   auto ret = PostRpcResponse(entry, call, result);
   call = 0;
   return ret;
diff --git a/ntcore/src/test/native/cpp/EntryNotifierTest.cpp b/ntcore/src/test/native/cpp/EntryNotifierTest.cpp
index 54285dc873..e781b49b8c 100644
--- a/ntcore/src/test/native/cpp/EntryNotifierTest.cpp
+++ b/ntcore/src/test/native/cpp/EntryNotifierTest.cpp
@@ -3,6 +3,7 @@
 // the WPILib BSD license file in the root directory of this project.
 
 #include <wpi/Logger.h>
+#include <wpi/StringExtras.h>
 
 #include "EntryNotifier.h"
 #include "TestPrinters.h"
@@ -245,7 +246,7 @@ TEST_F(EntryNotifierTest, PollPrefixBasic) {
   int g4count = 0;
   for (const auto& result : results) {
     SCOPED_TRACE(::testing::PrintToString(result));
-    EXPECT_TRUE(wpi::StringRef(result.name).startswith("/foo"));
+    EXPECT_TRUE(wpi::starts_with(result.name, "/foo"));
     EXPECT_THAT(result.value, ValueEq(Value::MakeDouble(1)));
     EXPECT_EQ(Handle{result.entry}.GetType(), Handle::kEntry);
     EXPECT_EQ(Handle{result.entry}.GetInst(), 1);
diff --git a/ntcore/src/test/native/cpp/MockEntryNotifier.h b/ntcore/src/test/native/cpp/MockEntryNotifier.h
index 75e5cc3830..58518c687e 100644
--- a/ntcore/src/test/native/cpp/MockEntryNotifier.h
+++ b/ntcore/src/test/native/cpp/MockEntryNotifier.h
@@ -18,19 +18,19 @@ class MockEntryNotifier : public IEntryNotifier {
   MOCK_METHOD3(
       Add,
       unsigned int(std::function<void(const EntryNotification& event)> callback,
-                   wpi::StringRef prefix, unsigned int flags));
+                   std::string_view prefix, unsigned int flags));
   MOCK_METHOD3(
       Add,
       unsigned int(std::function<void(const EntryNotification& event)> callback,
                    unsigned int local_id, unsigned int flags));
   MOCK_METHOD3(AddPolled,
-               unsigned int(unsigned int poller_uid, wpi::StringRef prefix,
+               unsigned int(unsigned int poller_uid, std::string_view prefix,
                             unsigned int flags));
   MOCK_METHOD3(AddPolled,
                unsigned int(unsigned int poller_uid, unsigned int local_id,
                             unsigned int flags));
   MOCK_METHOD5(NotifyEntry,
-               void(unsigned int local_id, wpi::StringRef name,
+               void(unsigned int local_id, std::string_view name,
                     std::shared_ptr<Value> value, unsigned int flags,
                     unsigned int only_listener));
 };
diff --git a/ntcore/src/test/native/cpp/MockRpcServer.h b/ntcore/src/test/native/cpp/MockRpcServer.h
index 4196008381..be9e5129cf 100644
--- a/ntcore/src/test/native/cpp/MockRpcServer.h
+++ b/ntcore/src/test/native/cpp/MockRpcServer.h
@@ -16,7 +16,7 @@ class MockRpcServer : public IRpcServer {
   MOCK_METHOD1(RemoveRpc, void(unsigned int rpc_uid));
   MOCK_METHOD7(ProcessRpc,
                void(unsigned int local_id, unsigned int call_uid,
-                    wpi::StringRef name, wpi::StringRef params,
+                    std::string_view name, std::string_view params,
                     const ConnectionInfo& conn, SendResponseFunc send_response,
                     unsigned int rpc_uid));
 };
diff --git a/ntcore/src/test/native/cpp/StorageTest.cpp b/ntcore/src/test/native/cpp/StorageTest.cpp
index e8c80539ce..9294be4e87 100644
--- a/ntcore/src/test/native/cpp/StorageTest.cpp
+++ b/ntcore/src/test/native/cpp/StorageTest.cpp
@@ -4,6 +4,8 @@
 
 #include "StorageTest.h"
 
+#include <wpi/SmallString.h>
+#include <wpi/StringExtras.h>
 #include <wpi/raw_istream.h>
 #include <wpi/raw_ostream.h>
 
@@ -19,7 +21,6 @@ using ::testing::_;
 using ::testing::AnyNumber;
 using ::testing::IsNull;
 using ::testing::Return;
-using wpi::StringRef;
 
 namespace nt {
 
@@ -86,13 +87,13 @@ class StorageTestPersistent : public StorageTestEmpty {
     storage.SetEntryTypeValue("double/big", Value::MakeDouble(1.3e8));
     storage.SetEntryTypeValue("string/empty", Value::MakeString(""));
     storage.SetEntryTypeValue("string/normal", Value::MakeString("hello"));
-    storage.SetEntryTypeValue("string/special",
-                              Value::MakeString(StringRef("\0\3\5\n", 4)));
+    storage.SetEntryTypeValue(
+        "string/special", Value::MakeString(std::string_view("\0\3\5\n", 4)));
     storage.SetEntryTypeValue("string/quoted", Value::MakeString("\"a\""));
     storage.SetEntryTypeValue("raw/empty", Value::MakeRaw(""));
     storage.SetEntryTypeValue("raw/normal", Value::MakeRaw("hello"));
     storage.SetEntryTypeValue("raw/special",
-                              Value::MakeRaw(StringRef("\0\3\5\n", 4)));
+                              Value::MakeRaw(std::string_view("\0\3\5\n", 4)));
     storage.SetEntryTypeValue("booleanarr/empty",
                               Value::MakeBooleanArray(std::vector<int>{}));
     storage.SetEntryTypeValue("booleanarr/one",
@@ -114,7 +115,7 @@ class StorageTestPersistent : public StorageTestEmpty {
     storage.SetEntryTypeValue(
         "stringarr/two",
         Value::MakeStringArray(std::vector<std::string>{"hello", "world\n"}));
-    storage.SetEntryTypeValue(StringRef("\0\3\5\n", 4),
+    storage.SetEntryTypeValue(std::string_view("\0\3\5\n", 4),
                               Value::MakeBoolean(true));
     storage.SetEntryTypeValue("=", Value::MakeBoolean(true));
     ::testing::Mock::VerifyAndClearExpectations(&dispatcher);
@@ -127,7 +128,7 @@ class StorageTestPersistent : public StorageTestEmpty {
 
 class MockLoadWarn {
  public:
-  MOCK_METHOD2(Warn, void(size_t line, wpi::StringRef msg));
+  MOCK_METHOD2(Warn, void(size_t line, std::string_view msg));
 };
 
 TEST_P(StorageTestEmpty, Construct) {
@@ -166,7 +167,7 @@ TEST_P(StorageTestEmpty, SetEntryTypeValueAssignNew) {
               QueueOutgoing(MessageEq(Message::EntryAssign(
                                 "foo", GetParam() ? 0 : 0xffff, 1, value, 0)),
                             IsNull(), IsNull()));
-  EXPECT_CALL(notifier, NotifyEntry(0, StringRef("foo"), value,
+  EXPECT_CALL(notifier, NotifyEntry(0, std::string_view("foo"), value,
                                     NT_NOTIFY_NEW | NT_NOTIFY_LOCAL, UINT_MAX));
 
   storage.SetEntryTypeValue("foo", value);
@@ -189,7 +190,7 @@ TEST_P(StorageTestPopulateOne, SetEntryTypeValueAssignTypeChange) {
                                 "foo", GetParam() ? 0 : 0xffff, 2, value, 0)),
                             IsNull(), IsNull()));
   EXPECT_CALL(notifier,
-              NotifyEntry(0, StringRef("foo"), value,
+              NotifyEntry(0, std::string_view("foo"), value,
                           NT_NOTIFY_UPDATE | NT_NOTIFY_LOCAL, UINT_MAX));
 
   storage.SetEntryTypeValue("foo", value);
@@ -216,7 +217,7 @@ TEST_P(StorageTestPopulated, SetEntryTypeValueDifferentValue) {
                               IsNull(), IsNull()));
   }
   EXPECT_CALL(notifier,
-              NotifyEntry(1, StringRef("foo2"), value,
+              NotifyEntry(1, std::string_view("foo2"), value,
                           NT_NOTIFY_UPDATE | NT_NOTIFY_LOCAL, UINT_MAX));
   storage.SetEntryTypeValue("foo2", value);
   EXPECT_EQ(value, GetEntry("foo2")->value);
@@ -249,7 +250,7 @@ TEST_P(StorageTestEmpty, SetEntryValueAssignNew) {
               QueueOutgoing(MessageEq(Message::EntryAssign(
                                 "foo", GetParam() ? 0 : 0xffff, 1, value, 0)),
                             IsNull(), IsNull()));
-  EXPECT_CALL(notifier, NotifyEntry(0, StringRef("foo"), value,
+  EXPECT_CALL(notifier, NotifyEntry(0, std::string_view("foo"), value,
                                     NT_NOTIFY_NEW | NT_NOTIFY_LOCAL, UINT_MAX));
 
   EXPECT_TRUE(storage.SetEntryValue("foo", value));
@@ -285,7 +286,7 @@ TEST_P(StorageTestPopulated, SetEntryValueDifferentValue) {
                               IsNull(), IsNull()));
   }
   EXPECT_CALL(notifier,
-              NotifyEntry(1, StringRef("foo2"), value,
+              NotifyEntry(1, std::string_view("foo2"), value,
                           NT_NOTIFY_UPDATE | NT_NOTIFY_LOCAL, UINT_MAX));
 
   EXPECT_TRUE(storage.SetEntryValue("foo2", value));
@@ -320,7 +321,7 @@ TEST_P(StorageTestEmpty, SetDefaultEntryAssignNew) {
               QueueOutgoing(MessageEq(Message::EntryAssign(
                                 "foo", GetParam() ? 0 : 0xffff, 1, value, 0)),
                             IsNull(), IsNull()));
-  EXPECT_CALL(notifier, NotifyEntry(0, StringRef("foo"), value,
+  EXPECT_CALL(notifier, NotifyEntry(0, std::string_view("foo"), value,
                                     NT_NOTIFY_NEW | NT_NOTIFY_LOCAL, UINT_MAX));
 
   auto ret_val = storage.SetDefaultEntryValue("foo", value);
@@ -423,7 +424,7 @@ TEST_P(StorageTestPopulated, SetEntryFlagsDifferentValue) {
                                           IsNull(), IsNull()));
   }
   EXPECT_CALL(notifier,
-              NotifyEntry(1, StringRef("foo2"), _,
+              NotifyEntry(1, std::string_view("foo2"), _,
                           NT_NOTIFY_FLAGS | NT_NOTIFY_LOCAL, UINT_MAX));
   storage.SetEntryFlags("foo2", 1u);
   EXPECT_EQ(1u, GetEntry("foo2")->flags);
@@ -460,9 +461,10 @@ TEST_P(StorageTestPopulated, DeleteEntryExist) {
     EXPECT_CALL(dispatcher, QueueOutgoing(MessageEq(Message::EntryDelete(1)),
                                           IsNull(), IsNull()));
   }
-  EXPECT_CALL(notifier,
-              NotifyEntry(1, StringRef("foo2"), ValueEq(Value::MakeDouble(0)),
-                          NT_NOTIFY_DELETE | NT_NOTIFY_LOCAL, UINT_MAX));
+  EXPECT_CALL(
+      notifier,
+      NotifyEntry(1, std::string_view("foo2"), ValueEq(Value::MakeDouble(0)),
+                  NT_NOTIFY_DELETE | NT_NOTIFY_LOCAL, UINT_MAX));
 
   storage.DeleteEntry("foo2");
   ASSERT_EQ(1u, entries().count("foo2"));
@@ -562,58 +564,58 @@ TEST_P(StorageTestPersistent, SavePersistent) {
   wpi::SmallString<256> buf;
   wpi::raw_svector_ostream oss(buf);
   storage.SavePersistent(oss, false);
-  wpi::StringRef out = oss.str();
+  std::string_view out = oss.str();
   // std::fputs(out.c_str(), stderr);
-  wpi::StringRef line, rem = out;
-  std::tie(line, rem) = rem.split('\n');
+  std::string_view line, rem = out;
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("[NetworkTables Storage 3.0]", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("boolean \"\\x00\\x03\\x05\\n\"=true", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("boolean \"\\x3D\"=true", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("boolean \"boolean/false\"=false", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("boolean \"boolean/true\"=true", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("array boolean \"booleanarr/empty\"=", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("array boolean \"booleanarr/one\"=true", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("array boolean \"booleanarr/two\"=true,false", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("double \"double/big\"=1.3e+08", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("double \"double/neg\"=-1.5", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("double \"double/zero\"=0", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("array double \"doublearr/empty\"=", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("array double \"doublearr/one\"=0.5", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("array double \"doublearr/two\"=0.5,-0.25", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("raw \"raw/empty\"=", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("raw \"raw/normal\"=aGVsbG8=", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("raw \"raw/special\"=AAMFCg==", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("string \"string/empty\"=\"\"", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("string \"string/normal\"=\"hello\"", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("string \"string/quoted\"=\"\\\"a\\\"\"", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("string \"string/special\"=\"\\x00\\x03\\x05\\n\"", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("array string \"stringarr/empty\"=", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("array string \"stringarr/one\"=\"hello\"", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("array string \"stringarr/two\"=\"hello\",\"world\\n\"", line);
-  std::tie(line, rem) = rem.split('\n');
+  std::tie(line, rem) = wpi::split(rem, '\n');
   ASSERT_EQ("", line);
 }
 
@@ -624,13 +626,13 @@ TEST_P(StorageTestEmpty, LoadPersistentBadHeader) {
   wpi::raw_mem_istream iss("");
   EXPECT_CALL(
       warn,
-      Warn(1, wpi::StringRef("header line mismatch, ignoring rest of file")));
+      Warn(1, std::string_view("header line mismatch, ignoring rest of file")));
   EXPECT_FALSE(storage.LoadEntries(iss, "", true, warn_func));
 
   wpi::raw_mem_istream iss2("[NetworkTables");
   EXPECT_CALL(
       warn,
-      Warn(1, wpi::StringRef("header line mismatch, ignoring rest of file")));
+      Warn(1, std::string_view("header line mismatch, ignoring rest of file")));
 
   EXPECT_FALSE(storage.LoadEntries(iss2, "", true, warn_func));
   EXPECT_TRUE(entries().empty());
@@ -669,7 +671,7 @@ TEST_P(StorageTestEmpty, LoadPersistentAssign) {
                                             "foo", GetParam() ? 0 : 0xffff, 1,
                                             value, NT_PERSISTENT)),
                                         IsNull(), IsNull()));
-  EXPECT_CALL(notifier, NotifyEntry(0, StringRef("foo"),
+  EXPECT_CALL(notifier, NotifyEntry(0, std::string_view("foo"),
                                     ValueEq(Value::MakeBoolean(true)),
                                     NT_NOTIFY_NEW | NT_NOTIFY_LOCAL, UINT_MAX));
 
@@ -692,9 +694,10 @@ TEST_P(StorageTestPopulated, LoadPersistentUpdateFlags) {
                 QueueOutgoing(MessageEq(Message::FlagsUpdate(1, NT_PERSISTENT)),
                               IsNull(), IsNull()));
   }
-  EXPECT_CALL(notifier,
-              NotifyEntry(1, StringRef("foo2"), ValueEq(Value::MakeDouble(0)),
-                          NT_NOTIFY_FLAGS | NT_NOTIFY_LOCAL, UINT_MAX));
+  EXPECT_CALL(
+      notifier,
+      NotifyEntry(1, std::string_view("foo2"), ValueEq(Value::MakeDouble(0)),
+                  NT_NOTIFY_FLAGS | NT_NOTIFY_LOCAL, UINT_MAX));
 
   wpi::raw_mem_istream iss(
       "[NetworkTables Storage 3.0]\ndouble \"foo2\"=0.0\n");
@@ -719,9 +722,10 @@ TEST_P(StorageTestPopulated, LoadPersistentUpdateValue) {
                 QueueOutgoing(MessageEq(Message::EntryUpdate(1, 2, value)),
                               IsNull(), IsNull()));
   }
-  EXPECT_CALL(notifier,
-              NotifyEntry(1, StringRef("foo2"), ValueEq(Value::MakeDouble(1)),
-                          NT_NOTIFY_UPDATE | NT_NOTIFY_LOCAL, UINT_MAX));
+  EXPECT_CALL(
+      notifier,
+      NotifyEntry(1, std::string_view("foo2"), ValueEq(Value::MakeDouble(1)),
+                  NT_NOTIFY_UPDATE | NT_NOTIFY_LOCAL, UINT_MAX));
 
   wpi::raw_mem_istream iss(
       "[NetworkTables Storage 3.0]\ndouble \"foo2\"=1.0\n");
@@ -752,10 +756,11 @@ TEST_P(StorageTestPopulated, LoadPersistentUpdateValueFlags) {
                 QueueOutgoing(MessageEq(Message::FlagsUpdate(1, NT_PERSISTENT)),
                               IsNull(), IsNull()));
   }
-  EXPECT_CALL(notifier,
-              NotifyEntry(1, StringRef("foo2"), ValueEq(Value::MakeDouble(1)),
-                          NT_NOTIFY_FLAGS | NT_NOTIFY_UPDATE | NT_NOTIFY_LOCAL,
-                          UINT_MAX));
+  EXPECT_CALL(
+      notifier,
+      NotifyEntry(1, std::string_view("foo2"), ValueEq(Value::MakeDouble(1)),
+                  NT_NOTIFY_FLAGS | NT_NOTIFY_UPDATE | NT_NOTIFY_LOCAL,
+                  UINT_MAX));
 
   wpi::raw_mem_istream iss(
       "[NetworkTables Storage 3.0]\ndouble \"foo2\"=1.0\n");
@@ -817,13 +822,13 @@ TEST_P(StorageTestEmpty, LoadPersistent) {
   EXPECT_EQ(*Value::MakeString(""), *storage.GetEntryValue("string/empty"));
   EXPECT_EQ(*Value::MakeString("hello"),
             *storage.GetEntryValue("string/normal"));
-  EXPECT_EQ(*Value::MakeString(StringRef("\0\3\5\n", 4)),
+  EXPECT_EQ(*Value::MakeString(std::string_view("\0\3\5\n", 4)),
             *storage.GetEntryValue("string/special"));
   EXPECT_EQ(*Value::MakeString("\"a\""),
             *storage.GetEntryValue("string/quoted"));
   EXPECT_EQ(*Value::MakeRaw(""), *storage.GetEntryValue("raw/empty"));
   EXPECT_EQ(*Value::MakeRaw("hello"), *storage.GetEntryValue("raw/normal"));
-  EXPECT_EQ(*Value::MakeRaw(StringRef("\0\3\5\n", 4)),
+  EXPECT_EQ(*Value::MakeRaw(std::string_view("\0\3\5\n", 4)),
             *storage.GetEntryValue("raw/special"));
   EXPECT_EQ(*Value::MakeBooleanArray(std::vector<int>{}),
             *storage.GetEntryValue("booleanarr/empty"));
@@ -845,7 +850,7 @@ TEST_P(StorageTestEmpty, LoadPersistent) {
       *Value::MakeStringArray(std::vector<std::string>{"hello", "world\n"}),
       *storage.GetEntryValue("stringarr/two"));
   EXPECT_EQ(*Value::MakeBoolean(true),
-            *storage.GetEntryValue(StringRef("\0\3\5\n", 4)));
+            *storage.GetEntryValue(std::string_view("\0\3\5\n", 4)));
   EXPECT_EQ(*Value::MakeBoolean(true), *storage.GetEntryValue("="));
 }
 
@@ -856,7 +861,7 @@ TEST_P(StorageTestEmpty, LoadPersistentWarn) {
   wpi::raw_mem_istream iss(
       "[NetworkTables Storage 3.0]\nboolean \"foo\"=foo\n");
   EXPECT_CALL(
-      warn, Warn(2, wpi::StringRef(
+      warn, Warn(2, std::string_view(
                         "unrecognized boolean value, not 'true' or 'false'")));
   EXPECT_TRUE(storage.LoadEntries(iss, "", true, warn_func));
 
@@ -874,7 +879,7 @@ TEST_P(StorageTestEmpty, ProcessIncomingEntryAssign) {
         QueueOutgoing(MessageEq(Message::EntryAssign("foo", 0, 0, value, 0)),
                       IsNull(), IsNull()));
   }
-  EXPECT_CALL(notifier, NotifyEntry(0, StringRef("foo"), ValueEq(value),
+  EXPECT_CALL(notifier, NotifyEntry(0, std::string_view("foo"), ValueEq(value),
                                     NT_NOTIFY_NEW, UINT_MAX));
 
   storage.ProcessIncoming(
@@ -893,7 +898,7 @@ TEST_P(StorageTestPopulateOne, ProcessIncomingEntryAssign) {
         QueueOutgoing(MessageEq(Message::EntryAssign("foo", 0, 1, value, 0)),
                       IsNull(), conn.get()));
   }
-  EXPECT_CALL(notifier, NotifyEntry(0, StringRef("foo"), ValueEq(value),
+  EXPECT_CALL(notifier, NotifyEntry(0, std::string_view("foo"), ValueEq(value),
                                     NT_NOTIFY_UPDATE, UINT_MAX));
 
   storage.ProcessIncoming(Message::EntryAssign("foo", 0, 1, value, 0),
@@ -918,15 +923,16 @@ TEST_P(StorageTestPopulateOne, ProcessIncomingEntryAssignWithFlags) {
         QueueOutgoing(MessageEq(Message::EntryAssign("foo", 0, 1, value, 0x2)),
                       IsNull(), conn.get()));
     EXPECT_CALL(notifier,
-                NotifyEntry(0, StringRef("foo"), ValueEq(value),
+                NotifyEntry(0, std::string_view("foo"), ValueEq(value),
                             NT_NOTIFY_UPDATE | NT_NOTIFY_FLAGS, UINT_MAX));
   } else {
     // client forces flags back when an assign message is received for an
     // existing entry with different flags
     EXPECT_CALL(dispatcher, QueueOutgoing(MessageEq(Message::FlagsUpdate(0, 0)),
                                           IsNull(), IsNull()));
-    EXPECT_CALL(notifier, NotifyEntry(0, StringRef("foo"), ValueEq(value),
-                                      NT_NOTIFY_UPDATE, UINT_MAX));
+    EXPECT_CALL(notifier,
+                NotifyEntry(0, std::string_view("foo"), ValueEq(value),
+                            NT_NOTIFY_UPDATE, UINT_MAX));
   }
 
   storage.ProcessIncoming(Message::EntryAssign("foo", 0, 1, value, 0x2),
diff --git a/ntcore/src/test/native/cpp/StorageTest.h b/ntcore/src/test/native/cpp/StorageTest.h
index 782a9f1edb..3a1755f048 100644
--- a/ntcore/src/test/native/cpp/StorageTest.h
+++ b/ntcore/src/test/native/cpp/StorageTest.h
@@ -24,7 +24,7 @@ class StorageTest {
   Storage::EntriesMap& entries() { return storage.m_entries; }
   Storage::IdMap& idmap() { return storage.m_idmap; }
 
-  Storage::Entry* GetEntry(wpi::StringRef name) {
+  Storage::Entry* GetEntry(std::string_view name) {
     auto i = storage.m_entries.find(name);
     return i == storage.m_entries.end() ? &tmp_entry : i->getValue();
   }
diff --git a/ntcore/src/test/native/cpp/TestPrinters.cpp b/ntcore/src/test/native/cpp/TestPrinters.cpp
index f99529e210..49b407ba24 100644
--- a/ntcore/src/test/native/cpp/TestPrinters.cpp
+++ b/ntcore/src/test/native/cpp/TestPrinters.cpp
@@ -126,7 +126,7 @@ void PrintTo(const Value& value, std::ostream* os) {
       *os << value.GetDouble();
       break;
     case NT_STRING:
-      *os << '"' << value.GetString().str() << '"';
+      *os << '"' << value.GetString() << '"';
       break;
     case NT_RAW:
       *os << ::testing::PrintToString(value.GetRaw());
diff --git a/ntcore/src/test/native/cpp/TestPrinters.h b/ntcore/src/test/native/cpp/TestPrinters.h
index 9c9ae0140a..47c9eb4955 100644
--- a/ntcore/src/test/native/cpp/TestPrinters.h
+++ b/ntcore/src/test/native/cpp/TestPrinters.h
@@ -7,15 +7,15 @@
 
 #include <memory>
 #include <ostream>
-
-#include <wpi/StringRef.h>
+#include <string>
+#include <string_view>
 
 #include "gtest/gtest.h"
 
 namespace wpi {
 
-inline void PrintTo(StringRef str, ::std::ostream* os) {
-  ::testing::internal::PrintStringTo(str.str(), os);
+inline void PrintTo(std::string_view str, ::std::ostream* os) {
+  ::testing::internal::PrintStringTo(std::string{str}, os);
 }
 
 }  // namespace wpi
diff --git a/ntcore/src/test/native/cpp/ValueTest.cpp b/ntcore/src/test/native/cpp/ValueTest.cpp
index 10ae2353ac..271f7b67ae 100644
--- a/ntcore/src/test/native/cpp/ValueTest.cpp
+++ b/ntcore/src/test/native/cpp/ValueTest.cpp
@@ -2,11 +2,15 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
+#include <string_view>
+
 #include "TestPrinters.h"
 #include "Value_internal.h"
 #include "gtest/gtest.h"
 #include "networktables/NetworkTableValue.h"
 
+using namespace std::string_view_literals;
+
 namespace nt {
 
 class ValueTest : public ::testing::Test {};
@@ -66,7 +70,7 @@ TEST_F(ValueTest, String) {
   NT_InitValue(&cv);
   ConvertToC(*v, &cv);
   ASSERT_EQ(NT_STRING, cv.type);
-  ASSERT_EQ(wpi::StringRef("hello"), cv.data.v_string.str);
+  ASSERT_EQ("hello"sv, cv.data.v_string.str);
   ASSERT_EQ(5u, cv.data.v_string.len);
 
   v = Value::MakeString("goodbye");
@@ -74,7 +78,7 @@ TEST_F(ValueTest, String) {
   ASSERT_EQ("goodbye", v->GetString());
   ConvertToC(*v, &cv);
   ASSERT_EQ(NT_STRING, cv.type);
-  ASSERT_EQ(wpi::StringRef("goodbye"), cv.data.v_string.str);
+  ASSERT_EQ("goodbye"sv, cv.data.v_string.str);
   ASSERT_EQ(7u, cv.data.v_string.len);
 
   NT_DisposeValue(&cv);
@@ -88,7 +92,7 @@ TEST_F(ValueTest, Raw) {
   NT_InitValue(&cv);
   ConvertToC(*v, &cv);
   ASSERT_EQ(NT_RAW, cv.type);
-  ASSERT_EQ(wpi::StringRef("hello"), cv.data.v_string.str);
+  ASSERT_EQ("hello"sv, cv.data.v_string.str);
   ASSERT_EQ(5u, cv.data.v_string.len);
 
   v = Value::MakeRaw("goodbye");
@@ -96,7 +100,7 @@ TEST_F(ValueTest, Raw) {
   ASSERT_EQ("goodbye", v->GetRaw());
   ConvertToC(*v, &cv);
   ASSERT_EQ(NT_RAW, cv.type);
-  ASSERT_EQ(wpi::StringRef("goodbye"), cv.data.v_string.str);
+  ASSERT_EQ("goodbye"sv, cv.data.v_string.str);
   ASSERT_EQ(7u, cv.data.v_string.len);
 
   NT_DisposeValue(&cv);
@@ -190,17 +194,17 @@ TEST_F(ValueTest, StringArray) {
   auto v = Value::MakeStringArray(std::move(vec));
   ASSERT_EQ(NT_STRING_ARRAY, v->type());
   ASSERT_EQ(3u, v->GetStringArray().size());
-  ASSERT_EQ(wpi::StringRef("hello"), v->GetStringArray()[0]);
-  ASSERT_EQ(wpi::StringRef("goodbye"), v->GetStringArray()[1]);
-  ASSERT_EQ(wpi::StringRef("string"), v->GetStringArray()[2]);
+  ASSERT_EQ("hello"sv, v->GetStringArray()[0]);
+  ASSERT_EQ("goodbye"sv, v->GetStringArray()[1]);
+  ASSERT_EQ("string"sv, v->GetStringArray()[2]);
   NT_Value cv;
   NT_InitValue(&cv);
   ConvertToC(*v, &cv);
   ASSERT_EQ(NT_STRING_ARRAY, cv.type);
   ASSERT_EQ(3u, cv.data.arr_string.size);
-  ASSERT_EQ(wpi::StringRef("hello"), cv.data.arr_string.arr[0].str);
-  ASSERT_EQ(wpi::StringRef("goodbye"), cv.data.arr_string.arr[1].str);
-  ASSERT_EQ(wpi::StringRef("string"), cv.data.arr_string.arr[2].str);
+  ASSERT_EQ("hello"sv, cv.data.arr_string.arr[0].str);
+  ASSERT_EQ("goodbye"sv, cv.data.arr_string.arr[1].str);
+  ASSERT_EQ("string"sv, cv.data.arr_string.arr[2].str);
 
   // assign with same size
   vec.clear();
@@ -210,15 +214,15 @@ TEST_F(ValueTest, StringArray) {
   v = Value::MakeStringArray(vec);
   ASSERT_EQ(NT_STRING_ARRAY, v->type());
   ASSERT_EQ(3u, v->GetStringArray().size());
-  ASSERT_EQ(wpi::StringRef("s1"), v->GetStringArray()[0]);
-  ASSERT_EQ(wpi::StringRef("str2"), v->GetStringArray()[1]);
-  ASSERT_EQ(wpi::StringRef("string3"), v->GetStringArray()[2]);
+  ASSERT_EQ("s1"sv, v->GetStringArray()[0]);
+  ASSERT_EQ("str2"sv, v->GetStringArray()[1]);
+  ASSERT_EQ("string3"sv, v->GetStringArray()[2]);
   ConvertToC(*v, &cv);
   ASSERT_EQ(NT_STRING_ARRAY, cv.type);
   ASSERT_EQ(3u, cv.data.arr_string.size);
-  ASSERT_EQ(wpi::StringRef("s1"), cv.data.arr_string.arr[0].str);
-  ASSERT_EQ(wpi::StringRef("str2"), cv.data.arr_string.arr[1].str);
-  ASSERT_EQ(wpi::StringRef("string3"), cv.data.arr_string.arr[2].str);
+  ASSERT_EQ("s1"sv, cv.data.arr_string.arr[0].str);
+  ASSERT_EQ("str2"sv, cv.data.arr_string.arr[1].str);
+  ASSERT_EQ("string3"sv, cv.data.arr_string.arr[2].str);
 
   // assign with different size
   vec.clear();
@@ -227,13 +231,13 @@ TEST_F(ValueTest, StringArray) {
   v = Value::MakeStringArray(std::move(vec));
   ASSERT_EQ(NT_STRING_ARRAY, v->type());
   ASSERT_EQ(2u, v->GetStringArray().size());
-  ASSERT_EQ(wpi::StringRef("short"), v->GetStringArray()[0]);
-  ASSERT_EQ(wpi::StringRef("er"), v->GetStringArray()[1]);
+  ASSERT_EQ("short"sv, v->GetStringArray()[0]);
+  ASSERT_EQ("er"sv, v->GetStringArray()[1]);
   ConvertToC(*v, &cv);
   ASSERT_EQ(NT_STRING_ARRAY, cv.type);
   ASSERT_EQ(2u, cv.data.arr_string.size);
-  ASSERT_EQ(wpi::StringRef("short"), cv.data.arr_string.arr[0].str);
-  ASSERT_EQ(wpi::StringRef("er"), cv.data.arr_string.arr[1].str);
+  ASSERT_EQ("short"sv, cv.data.arr_string.arr[0].str);
+  ASSERT_EQ("er"sv, cv.data.arr_string.arr[1].str);
 
   NT_DisposeValue(&cv);
 }
diff --git a/ntcore/src/test/native/cpp/WireDecoderTest.cpp b/ntcore/src/test/native/cpp/WireDecoderTest.cpp
index b2c87b458f..313fd989c7 100644
--- a/ntcore/src/test/native/cpp/WireDecoderTest.cpp
+++ b/ntcore/src/test/native/cpp/WireDecoderTest.cpp
@@ -7,13 +7,14 @@
 #include <cfloat>
 #include <climits>
 #include <string>
-
-#include <wpi/StringRef.h>
+#include <string_view>
 
 #include "TestPrinters.h"
 #include "WireDecoder.h"
 #include "gtest/gtest.h"
 
+using namespace std::string_view_literals;
+
 namespace nt {
 
 class WireDecoderTest : public ::testing::Test {
@@ -21,8 +22,8 @@ class WireDecoderTest : public ::testing::Test {
   WireDecoderTest() {
     v_boolean = Value::MakeBoolean(true);
     v_double = Value::MakeDouble(1.0);
-    v_string = Value::MakeString(wpi::StringRef("hello"));
-    v_raw = Value::MakeRaw(wpi::StringRef("hello"));
+    v_string = Value::MakeString("hello"sv);
+    v_raw = Value::MakeRaw("hello"sv);
     v_boolean_array = Value::MakeBooleanArray(std::vector<int>{0, 1, 0});
     v_boolean_array_big = Value::MakeBooleanArray(std::vector<int>(255));
     v_double_array = Value::MakeDoubleArray(std::vector<double>{0.5, 0.25});
@@ -268,7 +269,7 @@ TEST_F(WireDecoderTest, ReadStringValue2) {
   ASSERT_TRUE(static_cast<bool>(val));
   EXPECT_EQ(*v_string, *val);
 
-  auto v_bye = Value::MakeString(wpi::StringRef("bye"));
+  auto v_bye = Value::MakeString("bye"sv);
   val = d.ReadValue(NT_STRING);
   ASSERT_TRUE(static_cast<bool>(val));
   EXPECT_EQ(*v_bye, *val);
@@ -443,7 +444,7 @@ TEST_F(WireDecoderTest, ReadStringValue3) {
   ASSERT_TRUE(static_cast<bool>(val));
   EXPECT_EQ(*v_string, *val);
 
-  auto v_bye = Value::MakeString(wpi::StringRef("bye"));
+  auto v_bye = Value::MakeString("bye"sv);
   val = d.ReadValue(NT_STRING);
   ASSERT_TRUE(static_cast<bool>(val));
   EXPECT_EQ(*v_bye, *val);
@@ -467,7 +468,7 @@ TEST_F(WireDecoderTest, ReadRawValue3) {
   ASSERT_TRUE(static_cast<bool>(val));
   EXPECT_EQ(*v_raw, *val);
 
-  auto v_bye = Value::MakeRaw(wpi::StringRef("bye"));
+  auto v_bye = Value::MakeRaw("bye"sv);
   val = d.ReadValue(NT_RAW);
   ASSERT_TRUE(static_cast<bool>(val));
   EXPECT_EQ(*v_bye, *val);
diff --git a/ntcore/src/test/native/cpp/WireEncoderTest.cpp b/ntcore/src/test/native/cpp/WireEncoderTest.cpp
index 46e362281c..b7141127d1 100644
--- a/ntcore/src/test/native/cpp/WireEncoderTest.cpp
+++ b/ntcore/src/test/native/cpp/WireEncoderTest.cpp
@@ -5,8 +5,7 @@
 #include <cfloat>
 #include <climits>
 #include <string>
-
-#include <wpi/StringRef.h>
+#include <string_view>
 
 #include "TestPrinters.h"
 #include "WireEncoder.h"
@@ -14,6 +13,8 @@
 
 #define BUFSIZE 1024
 
+using namespace std::string_view_literals;
+
 namespace nt {
 
 class WireEncoderTest : public ::testing::Test {
@@ -22,8 +23,8 @@ class WireEncoderTest : public ::testing::Test {
     v_empty = std::make_shared<Value>();
     v_boolean = Value::MakeBoolean(true);
     v_double = Value::MakeDouble(1.0);
-    v_string = Value::MakeString(wpi::StringRef("hello"));
-    v_raw = Value::MakeRaw(wpi::StringRef("hello"));
+    v_string = Value::MakeString("hello"sv);
+    v_raw = Value::MakeRaw("hello"sv);
     v_boolean_array = Value::MakeBooleanArray(std::vector<int>{0, 1, 0});
     v_boolean_array_big = Value::MakeBooleanArray(std::vector<int>(256));
     v_double_array = Value::MakeDoubleArray(std::vector<double>{0.5, 0.25});
@@ -83,8 +84,7 @@ TEST_F(WireEncoderTest, Write8) {
   e.Write8(0x101u);  // should be truncated
   e.Write8(0u);
   ASSERT_EQ(3u, e.size() - off);
-  ASSERT_EQ(wpi::StringRef("\x05\x01\x00", 3),
-            wpi::StringRef(e.data(), e.size()).substr(off));
+  ASSERT_EQ("\x05\x01\x00"sv, std::string_view(e.data(), e.size()).substr(off));
 }
 
 TEST_F(WireEncoderTest, Write16) {
@@ -98,8 +98,8 @@ TEST_F(WireEncoderTest, Write16) {
   e.Write16(0x4567u);
   e.Write16(0u);
   ASSERT_EQ(8u, e.size() - off);
-  ASSERT_EQ(wpi::StringRef("\x00\x05\x00\x01\x45\x67\x00\x00", 8),
-            wpi::StringRef(e.data(), e.size()).substr(off));
+  ASSERT_EQ("\x00\x05\x00\x01\x45\x67\x00\x00"sv,
+            std::string_view(e.data(), e.size()).substr(off));
 }
 
 TEST_F(WireEncoderTest, Write32) {
@@ -114,10 +114,10 @@ TEST_F(WireEncoderTest, Write32) {
   e.Write32(0x12345678ul);
   e.Write32(0ul);
   ASSERT_EQ(20u, e.size() - off);
-  ASSERT_EQ(wpi::StringRef("\x00\x00\x00\x05\x00\x00\x00\x01\x00\x00\xab\xcd"
-                           "\x12\x34\x56\x78\x00\x00\x00\x00",
-                           20),
-            wpi::StringRef(e.data(), e.size()).substr(off));
+  ASSERT_EQ(std::string_view("\x00\x00\x00\x05\x00\x00\x00\x01\x00\x00\xab\xcd"
+                             "\x12\x34\x56\x78\x00\x00\x00\x00",
+                             20),
+            std::string_view(e.data(), e.size()).substr(off));
 }
 
 TEST_F(WireEncoderTest, WriteDouble) {
@@ -134,13 +134,13 @@ TEST_F(WireEncoderTest, WriteDouble) {
   ASSERT_EQ(40u, e.size() - off);
   // golden values except min and max from
   // http://www.binaryconvert.com/result_double.html
-  ASSERT_EQ(wpi::StringRef("\x00\x00\x00\x00\x00\x00\x00\x00"
-                           "\x41\x0c\x13\x80\x00\x00\x00\x00"
-                           "\x7f\xf0\x00\x00\x00\x00\x00\x00"
-                           "\x00\x10\x00\x00\x00\x00\x00\x00"
-                           "\x7f\xef\xff\xff\xff\xff\xff\xff",
-                           40),
-            wpi::StringRef(e.data(), e.size()).substr(off));
+  ASSERT_EQ(std::string_view("\x00\x00\x00\x00\x00\x00\x00\x00"
+                             "\x41\x0c\x13\x80\x00\x00\x00\x00"
+                             "\x7f\xf0\x00\x00\x00\x00\x00\x00"
+                             "\x00\x10\x00\x00\x00\x00\x00\x00"
+                             "\x7f\xef\xff\xff\xff\xff\xff\xff",
+                             40),
+            std::string_view(e.data(), e.size()).substr(off));
 }
 
 TEST_F(WireEncoderTest, WriteUleb128) {
@@ -153,8 +153,8 @@ TEST_F(WireEncoderTest, WriteUleb128) {
   e.WriteUleb128(0x7ful);
   e.WriteUleb128(0x80ul);
   ASSERT_EQ(4u, e.size() - off);
-  ASSERT_EQ(wpi::StringRef("\x00\x7f\x80\x01", 4),
-            wpi::StringRef(e.data(), e.size()).substr(off));
+  ASSERT_EQ("\x00\x7f\x80\x01"sv,
+            std::string_view(e.data(), e.size()).substr(off));
 }
 
 TEST_F(WireEncoderTest, WriteType) {
@@ -173,8 +173,8 @@ TEST_F(WireEncoderTest, WriteType) {
   e.WriteType(NT_RPC);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(8u, e.size() - off);
-  ASSERT_EQ(wpi::StringRef("\x00\x01\x02\x03\x10\x11\x12\x20", 8),
-            wpi::StringRef(e.data(), e.size()).substr(off));
+  ASSERT_EQ("\x00\x01\x02\x03\x10\x11\x12\x20"sv,
+            std::string_view(e.data(), e.size()).substr(off));
 }
 
 TEST_F(WireEncoderTest, WriteTypeError) {
@@ -235,7 +235,7 @@ TEST_F(WireEncoderTest, WriteBooleanValue2) {
   e.WriteValue(*v_false);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(2u, e.size());
-  ASSERT_EQ(wpi::StringRef("\x01\x00", 2), wpi::StringRef(e.data(), e.size()));
+  ASSERT_EQ("\x01\x00"sv, std::string_view(e.data(), e.size()));
 }
 
 TEST_F(WireEncoderTest, WriteDoubleValue2) {
@@ -243,8 +243,8 @@ TEST_F(WireEncoderTest, WriteDoubleValue2) {
   e.WriteValue(*v_double);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(8u, e.size());
-  ASSERT_EQ(wpi::StringRef("\x3f\xf0\x00\x00\x00\x00\x00\x00", 8),
-            wpi::StringRef(e.data(), e.size()));
+  ASSERT_EQ("\x3f\xf0\x00\x00\x00\x00\x00\x00"sv,
+            std::string_view(e.data(), e.size()));
 }
 
 TEST_F(WireEncoderTest, WriteStringValue2) {
@@ -252,8 +252,7 @@ TEST_F(WireEncoderTest, WriteStringValue2) {
   e.WriteValue(*v_string);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(7u, e.size());
-  ASSERT_EQ(wpi::StringRef("\x00\x05hello", 7),
-            wpi::StringRef(e.data(), e.size()));
+  ASSERT_EQ("\x00\x05hello"sv, std::string_view(e.data(), e.size()));
 }
 
 TEST_F(WireEncoderTest, WriteBooleanArrayValue2) {
@@ -261,15 +260,14 @@ TEST_F(WireEncoderTest, WriteBooleanArrayValue2) {
   e.WriteValue(*v_boolean_array);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(1u + 3u, e.size());
-  ASSERT_EQ(wpi::StringRef("\x03\x00\x01\x00", 4),
-            wpi::StringRef(e.data(), e.size()));
+  ASSERT_EQ("\x03\x00\x01\x00"sv, std::string_view(e.data(), e.size()));
 
   // truncated
   e.Reset();
   e.WriteValue(*v_boolean_array_big);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(1u + 255u, e.size());
-  ASSERT_EQ(wpi::StringRef("\xff\x00", 2), wpi::StringRef(e.data(), 2));
+  ASSERT_EQ("\xff\x00"sv, std::string_view(e.data(), 2));
 }
 
 TEST_F(WireEncoderTest, WriteDoubleArrayValue2) {
@@ -277,17 +275,17 @@ TEST_F(WireEncoderTest, WriteDoubleArrayValue2) {
   e.WriteValue(*v_double_array);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(1u + 2u * 8u, e.size());
-  ASSERT_EQ(wpi::StringRef("\x02\x3f\xe0\x00\x00\x00\x00\x00\x00"
-                           "\x3f\xd0\x00\x00\x00\x00\x00\x00",
-                           17),
-            wpi::StringRef(e.data(), e.size()));
+  ASSERT_EQ(std::string_view("\x02\x3f\xe0\x00\x00\x00\x00\x00\x00"
+                             "\x3f\xd0\x00\x00\x00\x00\x00\x00",
+                             17),
+            std::string_view(e.data(), e.size()));
 
   // truncated
   e.Reset();
   e.WriteValue(*v_double_array_big);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(1u + 255u * 8u, e.size());
-  ASSERT_EQ(wpi::StringRef("\xff\x00", 2), wpi::StringRef(e.data(), 2));
+  ASSERT_EQ("\xff\x00"sv, std::string_view(e.data(), 2));
 }
 
 TEST_F(WireEncoderTest, WriteStringArrayValue2) {
@@ -295,15 +293,15 @@ TEST_F(WireEncoderTest, WriteStringArrayValue2) {
   e.WriteValue(*v_string_array);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(1u + 7u + 9u, e.size());
-  ASSERT_EQ(wpi::StringRef("\x02\x00\x05hello\x00\x07goodbye", 17),
-            wpi::StringRef(e.data(), e.size()));
+  ASSERT_EQ("\x02\x00\x05hello\x00\x07goodbye"sv,
+            std::string_view(e.data(), e.size()));
 
   // truncated
   e.Reset();
   e.WriteValue(*v_string_array_big);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(1u + 255u * 3u, e.size());
-  ASSERT_EQ(wpi::StringRef("\xff\x00\x01", 3), wpi::StringRef(e.data(), 3));
+  ASSERT_EQ("\xff\x00\x01"sv, std::string_view(e.data(), 3));
 }
 
 TEST_F(WireEncoderTest, WriteValueError2) {
@@ -346,7 +344,7 @@ TEST_F(WireEncoderTest, WriteBooleanValue3) {
   e.WriteValue(*v_false);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(2u, e.size());
-  ASSERT_EQ(wpi::StringRef("\x01\x00", 2), wpi::StringRef(e.data(), e.size()));
+  ASSERT_EQ("\x01\x00"sv, std::string_view(e.data(), e.size()));
 }
 
 TEST_F(WireEncoderTest, WriteDoubleValue3) {
@@ -354,8 +352,8 @@ TEST_F(WireEncoderTest, WriteDoubleValue3) {
   e.WriteValue(*v_double);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(8u, e.size());
-  ASSERT_EQ(wpi::StringRef("\x3f\xf0\x00\x00\x00\x00\x00\x00", 8),
-            wpi::StringRef(e.data(), e.size()));
+  ASSERT_EQ("\x3f\xf0\x00\x00\x00\x00\x00\x00"sv,
+            std::string_view(e.data(), e.size()));
 }
 
 TEST_F(WireEncoderTest, WriteStringValue3) {
@@ -363,7 +361,7 @@ TEST_F(WireEncoderTest, WriteStringValue3) {
   e.WriteValue(*v_string);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(6u, e.size());
-  ASSERT_EQ(wpi::StringRef("\x05hello", 6), wpi::StringRef(e.data(), e.size()));
+  ASSERT_EQ("\x05hello"sv, std::string_view(e.data(), e.size()));
 }
 
 TEST_F(WireEncoderTest, WriteRawValue3) {
@@ -371,7 +369,7 @@ TEST_F(WireEncoderTest, WriteRawValue3) {
   e.WriteValue(*v_raw);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(6u, e.size());
-  ASSERT_EQ(wpi::StringRef("\x05hello", 6), wpi::StringRef(e.data(), e.size()));
+  ASSERT_EQ("\x05hello"sv, std::string_view(e.data(), e.size()));
 }
 
 TEST_F(WireEncoderTest, WriteBooleanArrayValue3) {
@@ -379,15 +377,14 @@ TEST_F(WireEncoderTest, WriteBooleanArrayValue3) {
   e.WriteValue(*v_boolean_array);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(1u + 3u, e.size());
-  ASSERT_EQ(wpi::StringRef("\x03\x00\x01\x00", 4),
-            wpi::StringRef(e.data(), e.size()));
+  ASSERT_EQ("\x03\x00\x01\x00"sv, std::string_view(e.data(), e.size()));
 
   // truncated
   e.Reset();
   e.WriteValue(*v_boolean_array_big);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(1u + 255u, e.size());
-  ASSERT_EQ(wpi::StringRef("\xff\x00", 2), wpi::StringRef(e.data(), 2));
+  ASSERT_EQ("\xff\x00"sv, std::string_view(e.data(), 2));
 }
 
 TEST_F(WireEncoderTest, WriteDoubleArrayValue3) {
@@ -395,17 +392,17 @@ TEST_F(WireEncoderTest, WriteDoubleArrayValue3) {
   e.WriteValue(*v_double_array);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(1u + 2u * 8u, e.size());
-  ASSERT_EQ(wpi::StringRef("\x02\x3f\xe0\x00\x00\x00\x00\x00\x00"
-                           "\x3f\xd0\x00\x00\x00\x00\x00\x00",
-                           17),
-            wpi::StringRef(e.data(), e.size()));
+  ASSERT_EQ(std::string_view("\x02\x3f\xe0\x00\x00\x00\x00\x00\x00"
+                             "\x3f\xd0\x00\x00\x00\x00\x00\x00",
+                             17),
+            std::string_view(e.data(), e.size()));
 
   // truncated
   e.Reset();
   e.WriteValue(*v_double_array_big);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(1u + 255u * 8u, e.size());
-  ASSERT_EQ(wpi::StringRef("\xff\x00", 2), wpi::StringRef(e.data(), 2));
+  ASSERT_EQ("\xff\x00"sv, std::string_view(e.data(), 2));
 }
 
 TEST_F(WireEncoderTest, WriteStringArrayValue3) {
@@ -413,15 +410,14 @@ TEST_F(WireEncoderTest, WriteStringArrayValue3) {
   e.WriteValue(*v_string_array);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(1u + 6u + 8u, e.size());
-  ASSERT_EQ(wpi::StringRef("\x02\x05hello\x07goodbye", 15),
-            wpi::StringRef(e.data(), e.size()));
+  ASSERT_EQ("\x02\x05hello\x07goodbye"sv, std::string_view(e.data(), e.size()));
 
   // truncated
   e.Reset();
   e.WriteValue(*v_string_array_big);
   ASSERT_EQ(nullptr, e.error());
   ASSERT_EQ(1u + 255u * 2u, e.size());
-  ASSERT_EQ(wpi::StringRef("\xff\x01", 2), wpi::StringRef(e.data(), 2));
+  ASSERT_EQ("\xff\x01"sv, std::string_view(e.data(), 2));
 }
 
 TEST_F(WireEncoderTest, WriteValueError3) {
@@ -445,14 +441,13 @@ TEST_F(WireEncoderTest, WriteString2) {
   e.WriteString(s_normal);
   EXPECT_EQ(nullptr, e.error());
   EXPECT_EQ(7u, e.size());
-  EXPECT_EQ(wpi::StringRef("\x00\x05hello", 7),
-            wpi::StringRef(e.data(), e.size()));
+  EXPECT_EQ("\x00\x05hello"sv, std::string_view(e.data(), e.size()));
 
   e.Reset();
   e.WriteString(s_long);
   EXPECT_EQ(nullptr, e.error());
   ASSERT_EQ(130u, e.size());
-  EXPECT_EQ(wpi::StringRef("\x00\x80**", 4), wpi::StringRef(e.data(), 4));
+  EXPECT_EQ("\x00\x80**"sv, std::string_view(e.data(), 4));
   EXPECT_EQ('*', e.data()[128]);
   EXPECT_EQ('x', e.data()[129]);
 
@@ -461,7 +456,7 @@ TEST_F(WireEncoderTest, WriteString2) {
   e.WriteString(s_big);
   EXPECT_EQ(nullptr, e.error());
   ASSERT_EQ(65537u, e.size());
-  EXPECT_EQ(wpi::StringRef("\xff\xff**", 4), wpi::StringRef(e.data(), 4));
+  EXPECT_EQ("\xff\xff**"sv, std::string_view(e.data(), 4));
   EXPECT_EQ('*', e.data()[65535]);
   EXPECT_EQ('x', e.data()[65536]);
 }
@@ -479,13 +474,13 @@ TEST_F(WireEncoderTest, WriteString3) {
   e.WriteString(s_normal);
   EXPECT_EQ(nullptr, e.error());
   EXPECT_EQ(6u, e.size());
-  EXPECT_EQ(wpi::StringRef("\x05hello", 6), wpi::StringRef(e.data(), e.size()));
+  EXPECT_EQ("\x05hello"sv, std::string_view(e.data(), e.size()));
 
   e.Reset();
   e.WriteString(s_long);
   EXPECT_EQ(nullptr, e.error());
   ASSERT_EQ(130u, e.size());
-  EXPECT_EQ(wpi::StringRef("\x80\x01**", 4), wpi::StringRef(e.data(), 4));
+  EXPECT_EQ("\x80\x01**"sv, std::string_view(e.data(), 4));
   EXPECT_EQ('*', e.data()[128]);
   EXPECT_EQ('x', e.data()[129]);
 
@@ -494,7 +489,7 @@ TEST_F(WireEncoderTest, WriteString3) {
   e.WriteString(s_big);
   EXPECT_EQ(nullptr, e.error());
   ASSERT_EQ(65540u, e.size());
-  EXPECT_EQ(wpi::StringRef("\x81\x80\x04*", 4), wpi::StringRef(e.data(), 4));
+  EXPECT_EQ("\x81\x80\x04*"sv, std::string_view(e.data(), 4));
   EXPECT_EQ('*', e.data()[65536]);
   EXPECT_EQ('x', e.data()[65537]);
   EXPECT_EQ('x', e.data()[65538]);
diff --git a/outlineviewer/.styleguide b/outlineviewer/.styleguide
index c8e055a4ca..d4917bfc9c 100644
--- a/outlineviewer/.styleguide
+++ b/outlineviewer/.styleguide
@@ -20,6 +20,7 @@ repoRootNameOverride {
 
 includeOtherLibs {
   ^GLFW
+  ^fmt/
   ^imgui
   ^ntcore
   ^wpi/
diff --git a/outlineviewer/src/main/native/cpp/main.cpp b/outlineviewer/src/main/native/cpp/main.cpp
index 061c9045bc..11428f5e68 100644
--- a/outlineviewer/src/main/native/cpp/main.cpp
+++ b/outlineviewer/src/main/native/cpp/main.cpp
@@ -5,9 +5,9 @@
 #include <memory>
 
 #include <GLFW/glfw3.h>
+#include <fmt/format.h>
 #include <imgui.h>
 #include <ntcore_cpp.h>
-#include <wpi/SmallString.h>
 #include <wpigui.h>
 
 #include "glass/Context.h"
@@ -21,13 +21,13 @@ namespace gui = wpi::gui;
 const char* GetWPILibVersion();
 
 namespace ov {
-wpi::StringRef GetResource_ov_16_png();
-wpi::StringRef GetResource_ov_32_png();
-wpi::StringRef GetResource_ov_48_png();
-wpi::StringRef GetResource_ov_64_png();
-wpi::StringRef GetResource_ov_128_png();
-wpi::StringRef GetResource_ov_256_png();
-wpi::StringRef GetResource_ov_512_png();
+std::string_view GetResource_ov_16_png();
+std::string_view GetResource_ov_32_png();
+std::string_view GetResource_ov_48_png();
+std::string_view GetResource_ov_64_png();
+std::string_view GetResource_ov_128_png();
+std::string_view GetResource_ov_256_png();
+std::string_view GetResource_ov_512_png();
 }  // namespace ov
 
 static std::unique_ptr<glass::NetworkTablesModel> gModel;
@@ -49,18 +49,14 @@ static void NtInitialize() {
     for (auto&& event : nt::PollConnectionListener(poller, 0, &timedOut)) {
       if ((nt::GetNetworkMode(inst) & NT_NET_MODE_SERVER) != 0) {
         // for server mode, just print number of clients connected
-        wpi::SmallString<64> title;
-        glfwSetWindowTitle(win, ("OutlineViewer - " +
-                                 wpi::Twine{nt::GetConnections(inst).size()} +
-                                 " Clients Connected")
-                                    .toNullTerminatedStringRef(title)
-                                    .data());
+        glfwSetWindowTitle(win,
+                           fmt::format("OutlineViewer - {} Clients Connected",
+                                       nt::GetConnections(inst).size())
+                               .c_str());
       } else if (event.connected) {
-        wpi::SmallString<64> title;
-        title = "OutlineViewer - Connected (";
-        title += event.conn.remote_ip;
-        title += ')';
-        glfwSetWindowTitle(win, title.c_str());
+        glfwSetWindowTitle(win, fmt::format("OutlineViewer - Connected ({})",
+                                            event.conn.remote_ip)
+                                    .c_str());
       } else {
         glfwSetWindowTitle(win, "OutlineViewer - DISCONNECTED");
       }
@@ -81,9 +77,8 @@ static void NtInitialize() {
       } else if (msg.level >= NT_LOG_WARNING) {
         level = "WARNING: ";
       }
-      gLog.Append(wpi::Twine{level} + msg.message + wpi::Twine{" ("} +
-                  msg.filename + wpi::Twine{':'} + wpi::Twine{msg.line} +
-                  wpi::Twine{")\n"});
+      gLog.Append(fmt::format("{}{} ({}:{})\n", level, msg.message,
+                              msg.filename, msg.line));
     }
   });
 
diff --git a/shared/resources.gradle b/shared/resources.gradle
index 50879e14b1..f5aa19f241 100644
--- a/shared/resources.gradle
+++ b/shared/resources.gradle
@@ -19,7 +19,7 @@ ext.createGenerateResourcesTask = { name, prefix, namespace, project ->
                 outputFile.withWriter { out ->
                     def inputBytes = inputFile.bytes
                     out.print '''#include <stddef.h>
-#include <wpi/StringRef.h>
+#include <string_view>
 extern "C" {
 static const unsigned char contents[] = { '''
 
@@ -36,8 +36,8 @@ const unsigned char* ${prefix}${funcName}(size_t* len) {
                     if (!namespace.isEmpty()) {
                         out.println "namespace ${namespace} {"
                     }
-                    out.println """wpi::StringRef ${funcName}() {
-  return wpi::StringRef(reinterpret_cast<const char*>(contents), ${fileBytes.size()});
+                    out.println """std::string_view ${funcName}() {
+  return std::string_view(reinterpret_cast<const char*>(contents), ${fileBytes.size()});
 }"""
                     if (!namespace.isEmpty()) {
                         out.println '}'
diff --git a/simulation/halsim_ds_socket/src/dev/native/cpp/main.cpp b/simulation/halsim_ds_socket/src/dev/native/cpp/main.cpp
index 0989409966..cf3adc6c7e 100644
--- a/simulation/halsim_ds_socket/src/dev/native/cpp/main.cpp
+++ b/simulation/halsim_ds_socket/src/dev/native/cpp/main.cpp
@@ -6,8 +6,6 @@
 
 #include <hal/DriverStation.h>
 #include <hal/HALBase.h>
-#include <wpi/Format.h>
-#include <wpi/raw_ostream.h>
 
 extern "C" int HALSIM_InitExtension(void);
 
diff --git a/simulation/halsim_ds_socket/src/main/native/cpp/DSCommPacket.cpp b/simulation/halsim_ds_socket/src/main/native/cpp/DSCommPacket.cpp
index 0aad44faa4..aeaf5e1101 100644
--- a/simulation/halsim_ds_socket/src/main/native/cpp/DSCommPacket.cpp
+++ b/simulation/halsim_ds_socket/src/main/native/cpp/DSCommPacket.cpp
@@ -13,7 +13,6 @@
 #include <hal/simulation/DriverStationData.h>
 #include <hal/simulation/MockHooks.h>
 #include <wpi/ArrayRef.h>
-#include <wpi/Format.h>
 
 using namespace halsim;
 
diff --git a/simulation/halsim_ds_socket/src/main/native/cpp/main.cpp b/simulation/halsim_ds_socket/src/main/native/cpp/main.cpp
index bac36b4334..c9fa585334 100644
--- a/simulation/halsim_ds_socket/src/main/native/cpp/main.cpp
+++ b/simulation/halsim_ds_socket/src/main/native/cpp/main.cpp
@@ -14,13 +14,14 @@
 #include <sys/types.h>
 
 #include <atomic>
+#include <cstdio>
 #include <cstring>
+#include <string_view>
 
 #include <DSCommPacket.h>
+#include <fmt/format.h>
 #include <hal/Extensions.h>
 #include <wpi/EventLoopRunner.h>
-#include <wpi/StringRef.h>
-#include <wpi/raw_ostream.h>
 #include <wpi/raw_uv_ostream.h>
 #include <wpi/uv/Tcp.h>
 #include <wpi/uv/Timer.h>
@@ -50,13 +51,13 @@ static SimpleBufferPool<4>& GetBufferPool() {
 }
 
 static void HandleTcpDataStream(Buffer& buf, size_t size, DataStore& store) {
-  wpi::StringRef data{buf.base, size};
+  std::string_view data{buf.base, size};
   while (!data.empty()) {
     if (store.m_frameSize == (std::numeric_limits<size_t>::max)()) {
       if (store.m_frame.size() < 2u) {
         size_t toCopy = (std::min)(2u - store.m_frame.size(), data.size());
-        store.m_frame.append(data.bytes_begin(), data.bytes_begin() + toCopy);
-        data = data.drop_front(toCopy);
+        store.m_frame.append(data.data(), data.data() + toCopy);
+        data.remove_prefix(toCopy);
         if (store.m_frame.size() < 2u) {
           return;  // need more data
         }
@@ -67,8 +68,8 @@ static void HandleTcpDataStream(Buffer& buf, size_t size, DataStore& store) {
     if (store.m_frameSize != (std::numeric_limits<size_t>::max)()) {
       size_t need = store.m_frameSize - (store.m_frame.size() - 2);
       size_t toCopy = (std::min)(need, data.size());
-      store.m_frame.append(data.bytes_begin(), data.bytes_begin() + toCopy);
-      data = data.drop_front(toCopy);
+      store.m_frame.append(data.data(), data.data() + toCopy);
+      data.remove_prefix(toCopy);
       need -= toCopy;
       if (need == 0) {
         auto ds = store.dsPacket;
@@ -118,8 +119,8 @@ static void SetupUdp(wpi::uv::Loop& loop) {
     udpLocal->Send(simAddr, wpi::ArrayRef<Buffer>{singleByte.get(), 1},
                    [](auto buf, Error err) {
                      if (err) {
-                       wpi::errs() << err.str() << "\n";
-                       wpi::errs().flush();
+                       fmt::print(stderr, "{}\n", err.str());
+                       std::fflush(stderr);
                      }
                    });
   });
@@ -146,8 +147,8 @@ static void SetupUdp(wpi::uv::Loop& loop) {
     udpLocal->Send(outAddr, sendBufs, [](auto bufs, Error err) {
       GetBufferPool().Release(bufs);
       if (err) {
-        wpi::errs() << err.str() << "\n";
-        wpi::errs().flush();
+        fmt::print(stderr, "{}\n", err.str());
+        std::fflush(stderr);
       }
     });
     ds->SendUDPToHALSim();
@@ -177,12 +178,12 @@ __declspec(dllexport)
   static bool once = false;
 
   if (once) {
-    wpi::errs() << "Error: cannot invoke HALSIM_InitExtension twice.\n";
+    std::fputs("Error: cannot invoke HALSIM_InitExtension twice.\n", stderr);
     return -1;
   }
   once = true;
 
-  wpi::outs() << "DriverStationSocket Initializing.\n";
+  std::puts("DriverStationSocket Initializing.");
 
   HAL_RegisterExtension("ds_socket", &gDSConnected);
 
@@ -192,7 +193,7 @@ __declspec(dllexport)
 
   eventLoopRunner->ExecAsync(SetupEventLoop);
 
-  wpi::outs() << "DriverStationSocket Initialized!\n";
+  std::puts("DriverStationSocket Initialized!");
   return 0;
 }
 }  // extern "C"
diff --git a/simulation/halsim_gui/src/main/native/cpp/AddressableLEDGui.cpp b/simulation/halsim_gui/src/main/native/cpp/AddressableLEDGui.cpp
index 37f2005245..586bbd8841 100644
--- a/simulation/halsim_gui/src/main/native/cpp/AddressableLEDGui.cpp
+++ b/simulation/halsim_gui/src/main/native/cpp/AddressableLEDGui.cpp
@@ -9,7 +9,6 @@
 #include <hal/Ports.h>
 #include <hal/simulation/AddressableLEDData.h>
 #include <imgui.h>
-#include <wpi/StringRef.h>
 
 #include "HALSimGui.h"
 
diff --git a/simulation/halsim_gui/src/main/native/cpp/DriverStationGui.cpp b/simulation/halsim_gui/src/main/native/cpp/DriverStationGui.cpp
index 8394a8ddb0..42ec8a35b7 100644
--- a/simulation/halsim_gui/src/main/native/cpp/DriverStationGui.cpp
+++ b/simulation/halsim_gui/src/main/native/cpp/DriverStationGui.cpp
@@ -13,15 +13,18 @@
 #include <cstring>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <GLFW/glfw3.h>
+#include <fmt/format.h>
+#include <hal/DriverStationTypes.h>
 #include <hal/simulation/DriverStationData.h>
 #include <hal/simulation/MockHooks.h>
 #include <imgui.h>
 #include <imgui_internal.h>
 #include <wpi/SmallVector.h>
-#include <wpi/StringRef.h>
+#include <wpi/StringExtras.h>
 #include <wpigui.h>
 
 #include "HALDataSource.h"
@@ -104,7 +107,7 @@ class KeyboardJoystick : public SystemJoystick {
   void ClearKey(int key);
   virtual const char* GetKeyName(int key) const = 0;
 
-  void ReadIni(wpi::StringRef name, wpi::StringRef value);
+  void ReadIni(std::string_view name, std::string_view value);
   void WriteIni(ImGuiTextBuffer* out_buf) const;
 
  protected:
@@ -210,14 +213,14 @@ class FMSSimModel : public glass::FMSModel {
   glass::DataSource* GetEnabledData() override { return &m_enabled; }
   glass::DataSource* GetTestData() override { return &m_test; }
   glass::DataSource* GetAutonomousData() override { return &m_autonomous; }
-  wpi::StringRef GetGameSpecificMessage(
+  std::string_view GetGameSpecificMessage(
       wpi::SmallVectorImpl<char>& buf) override {
     HAL_MatchInfo info;
     HALSIM_GetMatchInfo(&info);
     buf.clear();
     buf.append(info.gameSpecificMessage,
                info.gameSpecificMessage + info.gameSpecificMessageSize);
-    return wpi::StringRef(buf.begin(), buf.size());
+    return std::string_view(buf.begin(), buf.size());
   }
 
   void SetFmsAttached(bool val) override {
@@ -299,17 +302,15 @@ JoystickModel::JoystickModel(int index) : m_index{index} {
   axisCount = halAxes.count;
   for (int i = 0; i < axisCount; ++i) {
     axes[i] = std::make_unique<glass::DataSource>(
-        "Joystick[" + wpi::Twine{index} + "] Axis[" + wpi::Twine{i} +
-        wpi::Twine{']'});
+        fmt::format("Joystick[{}] Axis[{}]", index, i));
   }
 
   HAL_JoystickButtons halButtons;
   HALSIM_GetJoystickButtons(index, &halButtons);
   buttonCount = halButtons.count;
   for (int i = 0; i < buttonCount; ++i) {
-    buttons[i] =
-        new glass::DataSource("Joystick[" + wpi::Twine{index} + "] Button[" +
-                              wpi::Twine{i + 1} + wpi::Twine{']'});
+    buttons[i] = new glass::DataSource(
+        fmt::format("Joystick[{}] Button[{}]", index, i + 1));
     buttons[i]->SetDigital(true);
   }
   for (int i = buttonCount; i < 32; ++i) {
@@ -321,8 +322,7 @@ JoystickModel::JoystickModel(int index) : m_index{index} {
   povCount = halPOVs.count;
   for (int i = 0; i < povCount; ++i) {
     povs[i] = std::make_unique<glass::DataSource>(
-        "Joystick[" + wpi::Twine{index} + "] POV[" + wpi::Twine{i} +
-        wpi::Twine{']'});
+        fmt::format("Joystick[{}] POV [{}]", index, i));
   }
 
   m_callback =
@@ -360,10 +360,7 @@ void JoystickModel::CallbackFunc(const char*, void* param, const HAL_Value*) {
 // read/write joystick mapping to ini file
 static void* JoystickReadOpen(ImGuiContext* ctx, ImGuiSettingsHandler* handler,
                               const char* name) {
-  int num;
-  if (wpi::StringRef{name}.getAsInteger(10, num)) {
-    return nullptr;
-  }
+  int num = wpi::parse_integer<int>(name, 10).value_or(-1);
   if (num < 0 || num >= HAL_kMaxJoysticks) {
     return nullptr;
   }
@@ -371,21 +368,18 @@ static void* JoystickReadOpen(ImGuiContext* ctx, ImGuiSettingsHandler* handler,
 }
 
 static void JoystickReadLine(ImGuiContext* ctx, ImGuiSettingsHandler* handler,
-                             void* entry, const char* lineStr) {
+                             void* entry, const char* line) {
   RobotJoystick* joy = static_cast<RobotJoystick*>(entry);
   // format: guid=guid or useGamepad=0/1
-  wpi::StringRef line{lineStr};
-  auto [name, value] = line.split('=');
-  name = name.trim();
-  value = value.trim();
+  auto [name, value] = wpi::split(line, '=');
+  name = wpi::trim(name);
+  value = wpi::trim(value);
   if (name == "guid") {
     joy->guid = value;
   } else if (name == "useGamepad") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      joy->useGamepad = num.value();
     }
-    joy->useGamepad = num;
   } else {
     joy->name.ReadIni(name, value);
   }
@@ -417,10 +411,7 @@ static void JoystickWriteAll(ImGuiContext* ctx, ImGuiSettingsHandler* handler,
 static void* KeyboardJoystickReadOpen(ImGuiContext* ctx,
                                       ImGuiSettingsHandler* handler,
                                       const char* name) {
-  int num;
-  if (wpi::StringRef{name}.getAsInteger(10, num)) {
-    return nullptr;
-  }
+  int num = wpi::parse_integer<int>(name, 10).value_or(-1);
   if (num < 0 || num >= static_cast<int>(gKeyboardJoysticks.size())) {
     return nullptr;
   }
@@ -431,12 +422,11 @@ static void* KeyboardJoystickReadOpen(ImGuiContext* ctx,
 
 static void KeyboardJoystickReadLine(ImGuiContext* ctx,
                                      ImGuiSettingsHandler* handler, void* entry,
-                                     const char* lineStr) {
+                                     const char* line) {
   auto joy = static_cast<KeyboardJoystick*>(entry);
   // format: guid=guid or useGamepad=0/1
-  wpi::StringRef line{lineStr};
-  auto [name, value] = line.split('=');
-  joy->ReadIni(name.trim(), value.trim());
+  auto [name, value] = wpi::split(line, '=');
+  joy->ReadIni(wpi::trim(name), wpi::trim(value));
 }
 
 static void KeyboardJoystickWriteAll(ImGuiContext* ctx,
@@ -453,7 +443,7 @@ static void KeyboardJoystickWriteAll(ImGuiContext* ctx,
 static void* DriverStationReadOpen(ImGuiContext* ctx,
                                    ImGuiSettingsHandler* handler,
                                    const char* name) {
-  if (name == wpi::StringRef{"Main"}) {
+  if (name == std::string_view{"Main"}) {
     return &gDisableDS;
   }
   return nullptr;
@@ -461,35 +451,26 @@ static void* DriverStationReadOpen(ImGuiContext* ctx,
 
 static void DriverStationReadLine(ImGuiContext* ctx,
                                   ImGuiSettingsHandler* handler, void* entry,
-                                  const char* lineStr) {
-  wpi::StringRef line{lineStr};
-  auto [name, value] = line.split('=');
-  name = name.trim();
-  value = value.trim();
+                                  const char* line) {
+  auto [name, value] = wpi::split(line, '=');
+  name = wpi::trim(name);
+  value = wpi::trim(value);
   if (name == "disable") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      gDisableDS = num.value();
     }
-    gDisableDS = num;
   } else if (name == "zeroDisconnectedJoysticks") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      gZeroDisconnectedJoysticks = num.value();
     }
-    gZeroDisconnectedJoysticks = num;
   } else if (name == "enableDisableKeys") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      gUseEnableDisableHotkeys = num.value();
     }
-    gUseEnableDisableHotkeys = num;
   } else if (name == "estopKey") {
-    int num;
-    if (value.getAsInteger(10, num)) {
-      return;
+    if (auto num = wpi::parse_integer<int>(value, 10)) {
+      gUseEstopHotkey = num.value();
     }
-    gUseEstopHotkey = num;
   }
 }
 
@@ -914,92 +895,76 @@ void KeyboardJoystick::ClearKey(int key) {
   }
 }
 
-void KeyboardJoystick::ReadIni(wpi::StringRef name, wpi::StringRef value) {
-  if (name.startswith("axis")) {
-    name = name.drop_front(4);
+void KeyboardJoystick::ReadIni(std::string_view name, std::string_view value) {
+  if (wpi::starts_with(name, "axis")) {
+    name.remove_prefix(4);
     if (name == "Count") {
-      int v;
-      if (value.getAsInteger(10, v)) {
-        return;
+      if (auto v = wpi::parse_integer<int>(value, 10)) {
+        m_data.axes.count = (std::min)(v.value(), HAL_kMaxJoystickAxes);
       }
-      m_data.axes.count = (std::min)(v, HAL_kMaxJoystickAxes);
       return;
     }
 
-    unsigned int index;
-    if (name.consumeInteger(10, index)) {
-      return;
-    }
+    auto index = wpi::consume_integer<unsigned int>(&name, 10).value_or(
+        HAL_kMaxJoystickAxes);
     if (index >= HAL_kMaxJoystickAxes) {
       return;
     }
     if (name == "incKey") {
-      int v;
-      if (value.getAsInteger(10, v)) {
-        return;
+      if (auto v = wpi::parse_integer<int>(value, 10)) {
+        m_axisConfig[index].incKey = v.value();
       }
-      m_axisConfig[index].incKey = v;
     } else if (name == "decKey") {
-      int v;
-      if (value.getAsInteger(10, v)) {
-        return;
+      if (auto v = wpi::parse_integer<int>(value, 10)) {
+        m_axisConfig[index].decKey = v.value();
       }
-      m_axisConfig[index].decKey = v;
     } else if (name == "keyRate") {
-      std::sscanf(value.data(), "%f", &m_axisConfig[index].keyRate);
-    } else if (name == "decayRate") {
-      std::sscanf(value.data(), "%f", &m_axisConfig[index].decayRate);
-    } else if (name == "maxAbsValue") {
-      std::sscanf(value.data(), "%f", &m_axisConfig[index].maxAbsValue);
-    }
-  } else if (name.startswith("button")) {
-    name = name.drop_front(6);
-    if (name == "Count") {
-      int v;
-      if (value.getAsInteger(10, v)) {
-        return;
+      if (auto v = wpi::parse_float<float>(value)) {
+        m_axisConfig[index].keyRate = v.value();
+      }
+    } else if (name == "decayRate") {
+      if (auto v = wpi::parse_float<float>(value)) {
+        m_axisConfig[index].decayRate = v.value();
+      }
+    } else if (name == "maxAbsValue") {
+      if (auto v = wpi::parse_float<float>(value)) {
+        m_axisConfig[index].maxAbsValue = v.value();
+      }
+    }
+  } else if (wpi::starts_with(name, "button")) {
+    name.remove_prefix(6);
+    if (name == "Count") {
+      if (auto v = wpi::parse_integer<int>(value, 10)) {
+        m_data.buttons.count = (std::min)(v.value(), kMaxButtonCount);
       }
-      m_data.buttons.count = (std::min)(v, kMaxButtonCount);
       return;
     }
 
-    unsigned int index;
-    if (name.getAsInteger(10, index)) {
-      return;
-    }
+    auto index =
+        wpi::parse_integer<unsigned int>(name, 10).value_or(kMaxButtonCount);
     if (index >= kMaxButtonCount) {
       return;
     }
-    int v;
-    if (value.getAsInteger(10, v)) {
-      return;
-    }
+    int v = wpi::parse_integer<int>(value, 10).value_or(-1);
     if (v < 0 || v >= IM_ARRAYSIZE(ImGuiIO::KeysDown)) {
       return;
     }
     m_buttonKey[index] = v;
-  } else if (name.startswith("pov")) {
-    name = name.drop_front(3);
+  } else if (wpi::starts_with(name, "pov")) {
+    name.remove_prefix(3);
     if (name == "Count") {
-      int v;
-      if (value.getAsInteger(10, v)) {
-        return;
+      if (auto v = wpi::parse_integer<int>(value, 10)) {
+        m_data.povs.count = (std::min)(v.value(), HAL_kMaxJoystickPOVs);
       }
-      m_data.povs.count = (std::min)(v, HAL_kMaxJoystickPOVs);
       return;
     }
 
-    unsigned int index;
-    if (name.consumeInteger(10, index)) {
-      return;
-    }
+    auto index = wpi::consume_integer<unsigned int>(&name, 10).value_or(
+        HAL_kMaxJoystickPOVs);
     if (index >= HAL_kMaxJoystickPOVs) {
       return;
     }
-    int v;
-    if (value.getAsInteger(10, v)) {
-      return;
-    }
+    int v = wpi::parse_integer<int>(value, 10).value_or(-1);
     if (v < 0 || v >= IM_ARRAYSIZE(ImGuiIO::KeysDown)) {
       return;
     }
@@ -1409,8 +1374,9 @@ static void DisplayJoysticks() {
         }
         joy.sys = payload_sys;
         joy.guid.clear();
-        wpi::StringRef name{payload_sys->GetName()};
-        joy.useGamepad = name.startswith("Xbox") || name.contains("pad");
+        std::string_view name{payload_sys->GetName()};
+        joy.useGamepad =
+            wpi::starts_with(name, "Xbox") || wpi::contains(name, "pad");
       }
       ImGui::EndDragDropTarget();
     }
diff --git a/simulation/halsim_gui/src/main/native/cpp/DriverStationGui.h b/simulation/halsim_gui/src/main/native/cpp/DriverStationGui.h
index 80a7a73a81..51f7554620 100644
--- a/simulation/halsim_gui/src/main/native/cpp/DriverStationGui.h
+++ b/simulation/halsim_gui/src/main/native/cpp/DriverStationGui.h
@@ -6,11 +6,13 @@
 
 #include <glass/WindowManager.h>
 
+#include <string_view>
+
 namespace halsimgui {
 
 class DSManager : public glass::WindowManager {
  public:
-  explicit DSManager(const wpi::Twine& iniName) : WindowManager{iniName} {}
+  explicit DSManager(std::string_view iniName) : WindowManager{iniName} {}
 
   void DisplayMenu() override;
 };
diff --git a/simulation/halsim_gui/src/main/native/cpp/EncoderSimGui.cpp b/simulation/halsim_gui/src/main/native/cpp/EncoderSimGui.cpp
index d5bf569a41..56e8ea2334 100644
--- a/simulation/halsim_gui/src/main/native/cpp/EncoderSimGui.cpp
+++ b/simulation/halsim_gui/src/main/native/cpp/EncoderSimGui.cpp
@@ -9,8 +9,10 @@
 
 #include <limits>
 #include <memory>
+#include <string_view>
 #include <vector>
 
+#include <fmt/format.h>
 #include <hal/Ports.h>
 #include <hal/simulation/EncoderData.h>
 #include <hal/simulation/SimDeviceData.h>
@@ -24,14 +26,14 @@ namespace {
 
 class EncoderSimModel : public glass::EncoderModel {
  public:
-  EncoderSimModel(const wpi::Twine& id, int32_t index, int channelA,
+  EncoderSimModel(std::string_view id, int32_t index, int channelA,
                   int channelB)
-      : m_distancePerPulse(id + " Dist/Count"),
-        m_count(id + " Count"),
-        m_period(id + " Period"),
-        m_direction(id + " Direction"),
-        m_distance(id + " Distance"),
-        m_rate(id + " Rate"),
+      : m_distancePerPulse(fmt::format("{} Dist/Count", id)),
+        m_count(fmt::format("{} Count", id)),
+        m_period(fmt::format("{} Period", id)),
+        m_direction(fmt::format("{} Direction", id)),
+        m_distance(fmt::format("{} Distance", id)),
+        m_rate(fmt::format("{} Rate", id)),
         m_index{index},
         m_channelA{channelA},
         m_channelB{channelB},
@@ -48,8 +50,7 @@ class EncoderSimModel : public glass::EncoderModel {
   }
 
   EncoderSimModel(int32_t index, int channelA, int channelB)
-      : EncoderSimModel("Encoder[" + wpi::Twine(channelA) + wpi::Twine(',') +
-                            wpi::Twine(channelB) + wpi::Twine(']'),
+      : EncoderSimModel(fmt::format("Encoder[{},{}]", channelA, channelB),
                         index, channelA, channelB) {}
 
   explicit EncoderSimModel(int32_t index)
diff --git a/simulation/halsim_gui/src/main/native/cpp/HALProvider.cpp b/simulation/halsim_gui/src/main/native/cpp/HALProvider.cpp
index 0f2a2f8cfa..72b9c29db4 100644
--- a/simulation/halsim_gui/src/main/native/cpp/HALProvider.cpp
+++ b/simulation/halsim_gui/src/main/native/cpp/HALProvider.cpp
@@ -56,7 +56,7 @@ void HALProvider::Update() {
   }
 }
 
-glass::Model* HALProvider::GetModel(wpi::StringRef name) {
+glass::Model* HALProvider::GetModel(std::string_view name) {
   auto it = FindModelEntry(name);
   if (it == m_modelEntries.end() || (*it)->name != name) {
     return nullptr;
diff --git a/simulation/halsim_gui/src/main/native/cpp/SimDeviceGui.cpp b/simulation/halsim_gui/src/main/native/cpp/SimDeviceGui.cpp
index 4a4de4bb23..62e289632f 100644
--- a/simulation/halsim_gui/src/main/native/cpp/SimDeviceGui.cpp
+++ b/simulation/halsim_gui/src/main/native/cpp/SimDeviceGui.cpp
@@ -7,9 +7,11 @@
 #include <glass/other/DeviceTree.h>
 #include <stdint.h>
 
+#include <fmt/format.h>
 #include <hal/SimDevice.h>
 #include <hal/simulation/SimDeviceData.h>
 #include <wpi/DenseMap.h>
+#include <wpi/StringExtras.h>
 
 #include "HALDataSource.h"
 #include "HALSimGui.h"
@@ -21,7 +23,7 @@ class SimValueSource : public glass::DataSource {
  public:
   explicit SimValueSource(HAL_SimValueHandle handle, const char* device,
                           const char* name)
-      : DataSource(wpi::Twine{device} + wpi::Twine{'-'} + name),
+      : DataSource(fmt::format("{}-{}", device, name)),
         m_callback{HALSIM_RegisterSimValueChangedCallback(
             handle, this, CallbackFunc, true)} {}
   ~SimValueSource() override {
@@ -137,11 +139,11 @@ static void DisplaySimValue(const char* name, void* data,
 
 static void DisplaySimDevice(const char* name, void* data,
                              HAL_SimDeviceHandle handle) {
-  wpi::StringRef id{name};
+  std::string_view id{name};
   if (!gSimDevicesShowPrefix) {
     // only show "Foo" portion of "Accel:Foo"
-    wpi::StringRef type;
-    std::tie(type, id) = id.split(':');
+    std::string_view type;
+    std::tie(type, id) = wpi::split(id, ':');
     if (id.empty()) {
       id = type;
     }
diff --git a/simulation/halsim_gui/src/main/native/cpp/main.cpp b/simulation/halsim_gui/src/main/native/cpp/main.cpp
index 2950b4d6df..a0db3d0a2c 100644
--- a/simulation/halsim_gui/src/main/native/cpp/main.cpp
+++ b/simulation/halsim_gui/src/main/native/cpp/main.cpp
@@ -5,11 +5,12 @@
 #include <glass/Context.h>
 #include <glass/other/Plot.h>
 
+#include <cstdio>
+#include <string_view>
+
 #include <hal/Extensions.h>
 #include <hal/Main.h>
 #include <imgui.h>
-#include <wpi/StringRef.h>
-#include <wpi/raw_ostream.h>
 #include <wpigui.h>
 
 #include "AccelerometerSimGui.h"
@@ -41,7 +42,7 @@ extern "C" {
 __declspec(dllexport)
 #endif
     int HALSIM_InitExtension(void) {
-  wpi::outs() << "Simulator GUI Initializing.\n";
+  std::puts("Simulator GUI Initializing.");
 
   gui::CreateContext();
   glass::CreateContext();
@@ -102,7 +103,7 @@ __declspec(dllexport)
   }
   HAL_RegisterExtensionListener(
       nullptr, [](void*, const char* name, void* data) {
-        if (wpi::StringRef{name} == "ds_socket") {
+        if (std::string_view{name} == "ds_socket") {
           DriverStationGui::SetDSSocketExtension(data);
         }
       });
@@ -114,7 +115,7 @@ __declspec(dllexport)
         gui::DestroyContext();
       },
       [](void*) { gui::Exit(); });
-  wpi::outs() << "Simulator GUI Initialized!\n";
+  std::puts("Simulator GUI Initialized!");
 
   return 0;
 }
diff --git a/simulation/halsim_gui/src/main/native/include/HALProvider.h b/simulation/halsim_gui/src/main/native/include/HALProvider.h
index 2dcbc0d632..e3098db416 100644
--- a/simulation/halsim_gui/src/main/native/include/HALProvider.h
+++ b/simulation/halsim_gui/src/main/native/include/HALProvider.h
@@ -10,19 +10,18 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <vector>
 
-#include <wpi/StringRef.h>
-
 namespace halsimgui {
 
 class HALProvider : public glass::Provider<> {
  public:
-  explicit HALProvider(const wpi::Twine& iniName) : Provider{iniName} {}
+  explicit HALProvider(std::string_view iniName) : Provider{iniName} {}
 
   void DisplayMenu() override;
 
-  glass::Model* GetModel(wpi::StringRef name);
+  glass::Model* GetModel(std::string_view name);
 
   /**
    * Returns true if outputs are disabled.
diff --git a/simulation/halsim_ws_client/src/main/native/cpp/HALSimWS.cpp b/simulation/halsim_ws_client/src/main/native/cpp/HALSimWS.cpp
index da6253d589..9c23885843 100644
--- a/simulation/halsim_ws_client/src/main/native/cpp/HALSimWS.cpp
+++ b/simulation/halsim_ws_client/src/main/native/cpp/HALSimWS.cpp
@@ -4,8 +4,10 @@
 
 #include "HALSimWS.h"
 
+#include <cstdio>
+
+#include <fmt/format.h>
 #include <wpi/SmallString.h>
-#include <wpi/raw_ostream.h>
 #include <wpi/uv/util.h>
 
 #include "HALSimWSClientConnection.h"
@@ -22,7 +24,7 @@ HALSimWS::HALSimWS(wpi::uv::Loop& loop, ProviderContainer& providers,
       m_providers(providers),
       m_simDevicesProvider(simDevicesProvider) {
   m_loop.error.connect([](uv::Error err) {
-    wpi::errs() << "HALSim WS Client libuv Error: " << err.str() << "\n";
+    fmt::print(stderr, "HALSim WS Client libuv Error: {}\n", err.str());
   });
 
   m_tcp_client = uv::Tcp::Create(m_loop);
@@ -50,7 +52,7 @@ bool HALSimWS::Initialize() {
     try {
       m_port = std::stoi(port);
     } catch (const std::invalid_argument& err) {
-      wpi::errs() << "Error decoding HALSIMWS_PORT (" << err.what() << ")\n";
+      fmt::print(stderr, "Error decoding HALSIMWS_PORT ({})\n", err.what());
       return false;
     }
   } else {
@@ -83,13 +85,12 @@ void HALSimWS::Start() {
         m_connect_timer->Start(uv::Timer::Time(kTcpConnectAttemptTimeout));
       });
 
-  m_tcp_client->closed.connect(
-      []() { wpi::outs() << "TCP connection closed\n"; });
+  m_tcp_client->closed.connect([]() { std::puts("TCP connection closed"); });
 
   // Set up the connection timer
-  wpi::outs() << "HALSimWS Initialized\n";
-  wpi::outs() << "Will attempt to connect to ws://" << m_host << ":" << m_port
-              << m_uri << "\n";
+  std::puts("HALSimWS Initialized");
+  fmt::print("Will attempt to connect to ws://{}:{}{}\n", m_host, m_port,
+             m_uri);
 
   // Set up the timer to attempt connection
   m_connect_timer->timeout.connect([this] { AttemptConnect(); });
@@ -102,7 +103,7 @@ void HALSimWS::Start() {
 void HALSimWS::AttemptConnect() {
   m_connect_attempts++;
 
-  wpi::outs() << "Connection Attempt " << m_connect_attempts << "\n";
+  fmt::print("Connection Attempt {}\n", m_connect_attempts);
 
   struct sockaddr_in dest;
   uv::NameToAddr(m_host, m_port, &dest);
@@ -167,6 +168,6 @@ void HALSimWS::OnNetValueChanged(const wpi::json& msg) {
       provider->OnNetValueChanged(msg.at("data"));
     }
   } catch (wpi::json::exception& e) {
-    wpi::errs() << "Error with incoming message: " << e.what() << "\n";
+    fmt::print(stderr, "Error with incoming message: {}\n", e.what());
   }
 }
diff --git a/simulation/halsim_ws_client/src/main/native/cpp/HALSimWSClientConnection.cpp b/simulation/halsim_ws_client/src/main/native/cpp/HALSimWSClientConnection.cpp
index 4ebaf1d225..22dadb1245 100644
--- a/simulation/halsim_ws_client/src/main/native/cpp/HALSimWSClientConnection.cpp
+++ b/simulation/halsim_ws_client/src/main/native/cpp/HALSimWSClientConnection.cpp
@@ -4,7 +4,9 @@
 
 #include "HALSimWSClientConnection.h"
 
-#include <wpi/raw_ostream.h>
+#include <cstdio>
+
+#include <fmt/format.h>
 #include <wpi/raw_uv_ostream.h>
 
 #include "HALSimWS.h"
@@ -17,29 +19,29 @@ void HALSimWSClientConnection::Initialize() {
   // Get a shared pointer to ourselves
   auto self = this->shared_from_this();
 
-  auto ws =
-      wpi::WebSocket::CreateClient(*m_stream, m_client->GetTargetUri(),
-                                   wpi::Twine{m_client->GetTargetHost()} + ":" +
-                                       wpi::Twine{m_client->GetTargetPort()});
+  auto ws = wpi::WebSocket::CreateClient(
+      *m_stream, m_client->GetTargetUri(),
+      fmt::format("{}:{}", m_client->GetTargetHost(),
+                  m_client->GetTargetPort()));
 
   ws->SetData(self);
 
   m_websocket = ws.get();
 
   // Hook up events
-  m_websocket->open.connect_extended([this](auto conn, wpi::StringRef) {
+  m_websocket->open.connect_extended([this](auto conn, auto) {
     conn.disconnect();
 
     if (!m_client->RegisterWebsocket(shared_from_this())) {
-      wpi::errs() << "Unable to register websocket\n";
+      std::fputs("Unable to register websocket\n", stderr);
       return;
     }
 
     m_ws_connected = true;
-    wpi::outs() << "HALSimWS: WebSocket Connected\n";
+    std::puts("HALSimWS: WebSocket Connected");
   });
 
-  m_websocket->text.connect([this](wpi::StringRef msg, bool) {
+  m_websocket->text.connect([this](auto msg, bool) {
     if (!m_ws_connected) {
       return;
     }
@@ -50,7 +52,7 @@ void HALSimWSClientConnection::Initialize() {
     } catch (const wpi::json::parse_error& e) {
       std::string err("JSON parse failed: ");
       err += e.what();
-      wpi::errs() << err << "\n";
+      fmt::print(stderr, "{}\n", err);
       m_websocket->Fail(1003, err);
       return;
     }
@@ -58,9 +60,9 @@ void HALSimWSClientConnection::Initialize() {
     m_client->OnNetValueChanged(j);
   });
 
-  m_websocket->closed.connect([this](uint16_t, wpi::StringRef) {
+  m_websocket->closed.connect([this](uint16_t, auto) {
     if (m_ws_connected) {
-      wpi::outs() << "HALSimWS: Websocket Disconnected\n";
+      std::puts("HALSimWS: Websocket Disconnected");
       m_ws_connected = false;
 
       m_client->CloseWebsocket(shared_from_this());
@@ -90,8 +92,8 @@ void HALSimWSClientConnection::OnSimValueChanged(const wpi::json& msg) {
                                   }
 
                                   if (err) {
-                                    wpi::errs() << err.str() << "\n";
-                                    wpi::errs().flush();
+                                    fmt::print(stderr, "{}\n", err.str());
+                                    std::fflush(stderr);
                                   }
                                 });
   });
diff --git a/simulation/halsim_ws_client/src/main/native/cpp/main.cpp b/simulation/halsim_ws_client/src/main/native/cpp/main.cpp
index c5493713d6..8e2e2fa569 100644
--- a/simulation/halsim_ws_client/src/main/native/cpp/main.cpp
+++ b/simulation/halsim_ws_client/src/main/native/cpp/main.cpp
@@ -2,10 +2,10 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
+#include <cstdio>
 #include <memory>
 
 #include <hal/Extensions.h>
-#include <wpi/raw_ostream.h>
 
 #include "HALSimWSClient.h"
 
@@ -19,7 +19,7 @@ __declspec(dllexport)
 #endif
 
     int HALSIM_InitExtension(void) {
-  wpi::outs() << "HALSim WS Client Extension Initializing\n";
+  std::puts("HALSim WS Client Extension Initializing");
 
   HAL_OnShutdown(nullptr, [](void*) { gClient.reset(); });
 
@@ -28,7 +28,7 @@ __declspec(dllexport)
     return -1;
   }
 
-  wpi::outs() << "HALSim WS Client Extension Initialized\n";
+  std::puts("HALSim WS Client Extension Initialized");
   return 0;
 }
 
diff --git a/simulation/halsim_ws_client/src/main/native/include/HALSimWS.h b/simulation/halsim_ws_client/src/main/native/include/HALSimWS.h
index d2595470ce..9563482032 100644
--- a/simulation/halsim_ws_client/src/main/native/include/HALSimWS.h
+++ b/simulation/halsim_ws_client/src/main/native/include/HALSimWS.h
@@ -41,8 +41,8 @@ class HALSimWS : public std::enable_shared_from_this<HALSimWS> {
 
   void OnNetValueChanged(const wpi::json& msg);
 
-  wpi::StringRef GetTargetHost() const { return m_host; }
-  wpi::StringRef GetTargetUri() const { return m_uri; }
+  const std::string& GetTargetHost() const { return m_host; }
+  const std::string& GetTargetUri() const { return m_uri; }
   int GetTargetPort() const { return m_port; }
   wpi::uv::Loop& GetLoop() { return m_loop; }
 
diff --git a/simulation/halsim_ws_core/src/main/native/cpp/WSBaseProvider.cpp b/simulation/halsim_ws_core/src/main/native/cpp/WSBaseProvider.cpp
index 2e93f96ff1..16d92fa371 100644
--- a/simulation/halsim_ws_core/src/main/native/cpp/WSBaseProvider.cpp
+++ b/simulation/halsim_ws_core/src/main/native/cpp/WSBaseProvider.cpp
@@ -8,8 +8,9 @@
 
 namespace wpilibws {
 
-HALSimWSBaseProvider::HALSimWSBaseProvider(std::string key, std::string type)
-    : m_key(std::move(key)), m_type(std::move(type)) {}
+HALSimWSBaseProvider::HALSimWSBaseProvider(std::string_view key,
+                                           std::string_view type)
+    : m_key(key), m_type(type) {}
 
 void HALSimWSBaseProvider::OnNetValueChanged(const wpi::json& json) {
   // empty
diff --git a/simulation/halsim_ws_core/src/main/native/cpp/WSHalProviders.cpp b/simulation/halsim_ws_core/src/main/native/cpp/WSHalProviders.cpp
index e9576aeea8..4d6c024558 100644
--- a/simulation/halsim_ws_core/src/main/native/cpp/WSHalProviders.cpp
+++ b/simulation/halsim_ws_core/src/main/native/cpp/WSHalProviders.cpp
@@ -4,6 +4,8 @@
 
 #include "WSHalProviders.h"
 
+#include <fmt/format.h>
+
 namespace wpilibws {
 
 void HALSimWSHalProvider::OnNetworkConnected(
@@ -30,10 +32,10 @@ void HALSimWSHalProvider::ProcessHalCallback(const wpi::json& payload) {
 }
 
 HALSimWSHalChanProvider::HALSimWSHalChanProvider(int32_t channel,
-                                                 const std::string& key,
-                                                 const std::string& type)
+                                                 std::string_view key,
+                                                 std::string_view type)
     : HALSimWSHalProvider(key, type), m_channel(channel) {
-  m_deviceId = std::to_string(channel);
+  m_deviceId = fmt::format("{}", channel);
 }
 
 }  // namespace wpilibws
diff --git a/simulation/halsim_ws_core/src/main/native/cpp/WSProvider_DriverStation.cpp b/simulation/halsim_ws_core/src/main/native/cpp/WSProvider_DriverStation.cpp
index 44bca99eee..6fbc3d7a3c 100644
--- a/simulation/halsim_ws_core/src/main/native/cpp/WSProvider_DriverStation.cpp
+++ b/simulation/halsim_ws_core/src/main/native/cpp/WSProvider_DriverStation.cpp
@@ -6,6 +6,7 @@
 
 #include <algorithm>
 #include <atomic>
+#include <string_view>
 
 #include <hal/DriverStation.h>
 #include <hal/Extensions.h>
@@ -32,7 +33,7 @@ void HALSimWSProviderDriverStation::Initialize(WSRegisterFunc webRegisterFunc) {
     registered = true;
     HAL_RegisterExtensionListener(
         nullptr, [](void*, const char* name, void* data) {
-          if (wpi::StringRef{name} == "ds_socket") {
+          if (std::string_view{name} == "ds_socket") {
             gDSSocketConnected = static_cast<std::atomic<bool>*>(data);
           }
         });
diff --git a/simulation/halsim_ws_core/src/main/native/cpp/WSProvider_SimDevice.cpp b/simulation/halsim_ws_core/src/main/native/cpp/WSProvider_SimDevice.cpp
index a296c06291..93852b6703 100644
--- a/simulation/halsim_ws_core/src/main/native/cpp/WSProvider_SimDevice.cpp
+++ b/simulation/halsim_ws_core/src/main/native/cpp/WSProvider_SimDevice.cpp
@@ -7,7 +7,9 @@
 #include <algorithm>
 #include <cmath>
 
+#include <fmt/format.h>
 #include <hal/Ports.h>
+#include <wpi/StringExtras.h>
 
 namespace wpilibws {
 
@@ -140,7 +142,7 @@ void HALSimWSProviderSimDevice::OnValueCreated(const char* name,
         break;
     }
   }
-  std::string key = (wpi::Twine(prefix) + name).str();
+  std::string key = fmt::format("{}{}", prefix, name);
   auto data = std::make_unique<SimDeviceValueData>();
   data->device = this;
   data->handle = handle;
@@ -258,15 +260,15 @@ HALSimWSProviderSimDevices::~HALSimWSProviderSimDevices() {
 void HALSimWSProviderSimDevices::DeviceCreatedCallback(
     const char* name, HAL_SimDeviceHandle handle) {
   // Map "Accel:Foo" -> type=Accel, device=Foo
-  auto [type, id] = wpi::StringRef{name}.split(':');
+  auto [type, id] = wpi::split(name, ':');
   std::shared_ptr<HALSimWSProviderSimDevice> dev;
   if (id.empty()) {
-    auto key = ("SimDevice/" + type).str();
+    auto key = fmt::format("SimDevice/{}", type);
     dev = std::make_shared<HALSimWSProviderSimDevice>(handle, key, "SimDevice",
                                                       type);
     m_providers.Add(key, dev);
   } else {
-    auto key = (type + "/" + id).str();
+    auto key = fmt::format("{}/{}", type, id);
     dev = std::make_shared<HALSimWSProviderSimDevice>(handle, key, type, id);
     m_providers.Add(key, dev);
   }
diff --git a/simulation/halsim_ws_core/src/main/native/cpp/WSProvider_Solenoid.cpp b/simulation/halsim_ws_core/src/main/native/cpp/WSProvider_Solenoid.cpp
index c87cb82a40..c376d3a59d 100644
--- a/simulation/halsim_ws_core/src/main/native/cpp/WSProvider_Solenoid.cpp
+++ b/simulation/halsim_ws_core/src/main/native/cpp/WSProvider_Solenoid.cpp
@@ -4,6 +4,7 @@
 
 #include "WSProvider_Solenoid.h"
 
+#include <fmt/format.h>
 #include <hal/Ports.h>
 #include <hal/simulation/CTREPCMData.h>
 
@@ -22,9 +23,7 @@ void HALSimWSProviderSolenoid::Initialize(WSRegisterFunc webRegisterFunc) {
        ++CTREPCMIndex) {
     for (int32_t solenoidIndex = 0;
          solenoidIndex < HAL_GetNumSolenoidChannels(); ++solenoidIndex) {
-      auto key = ("Solenoid/" + wpi::Twine(CTREPCMIndex) + "," +
-                  wpi::Twine(solenoidIndex))
-                     .str();
+      auto key = fmt::format("Solenoid/{},{}", CTREPCMIndex, solenoidIndex);
       auto ptr = std::make_unique<HALSimWSProviderSolenoid>(
           CTREPCMIndex, solenoidIndex, key, "Solenoid");
       webRegisterFunc(key, std::move(ptr));
@@ -39,8 +38,7 @@ HALSimWSProviderSolenoid::HALSimWSProviderSolenoid(int32_t CTREPCMChannel,
     : HALSimWSHalProvider(key, type),
       m_pcmIndex(CTREPCMChannel),
       m_solenoidIndex(solenoidChannel) {
-  m_deviceId =
-      std::to_string(m_pcmIndex) + "," + std::to_string(solenoidChannel);
+  m_deviceId = fmt::format("{},{}", m_pcmIndex, solenoidChannel);
 }
 
 HALSimWSProviderSolenoid::~HALSimWSProviderSolenoid() {
diff --git a/simulation/halsim_ws_core/src/main/native/include/WSBaseProvider.h b/simulation/halsim_ws_core/src/main/native/include/WSBaseProvider.h
index 39fadb6708..268c47af4e 100644
--- a/simulation/halsim_ws_core/src/main/native/include/WSBaseProvider.h
+++ b/simulation/halsim_ws_core/src/main/native/include/WSBaseProvider.h
@@ -7,6 +7,7 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <string_view>
 
 #include <wpi/json.h>
 
@@ -16,7 +17,8 @@ namespace wpilibws {
 
 class HALSimWSBaseProvider {
  public:
-  explicit HALSimWSBaseProvider(std::string key, std::string type = "");
+  explicit HALSimWSBaseProvider(std::string_view key,
+                                std::string_view type = "");
   virtual ~HALSimWSBaseProvider() = default;
 
   HALSimWSBaseProvider(const HALSimWSBaseProvider&) = delete;
@@ -34,8 +36,8 @@ class HALSimWSBaseProvider {
   // network -> sim
   virtual void OnNetValueChanged(const wpi::json& json);
 
-  const std::string GetDeviceType() { return m_type; }
-  const std::string GetDeviceId() { return m_deviceId; }
+  const std::string& GetDeviceType() { return m_type; }
+  const std::string& GetDeviceId() { return m_deviceId; }
 
  protected:
   // sim -> network
diff --git a/simulation/halsim_ws_core/src/main/native/include/WSHalProviders.h b/simulation/halsim_ws_core/src/main/native/include/WSHalProviders.h
index ce12c59495..e1bc1f85ac 100644
--- a/simulation/halsim_ws_core/src/main/native/include/WSHalProviders.h
+++ b/simulation/halsim_ws_core/src/main/native/include/WSHalProviders.h
@@ -7,6 +7,7 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <string_view>
 
 #include <hal/simulation/NotifyListener.h>
 #include <wpi/json.h>
@@ -41,8 +42,8 @@ class HALSimWSHalProvider : public HALSimWSBaseProvider {
 // provider generates per-channel diffs
 class HALSimWSHalChanProvider : public HALSimWSHalProvider {
  public:
-  explicit HALSimWSHalChanProvider(int32_t channel, const std::string& key,
-                                   const std::string& type);
+  explicit HALSimWSHalChanProvider(int32_t channel, std::string_view key,
+                                   std::string_view type);
 
   int32_t GetChannel() { return m_channel; }
 
@@ -51,15 +52,14 @@ class HALSimWSHalChanProvider : public HALSimWSHalProvider {
 };
 
 using WSRegisterFunc = std::function<void(
-    const std::string&, std::shared_ptr<HALSimWSBaseProvider>)>;
+    std::string_view, std::shared_ptr<HALSimWSBaseProvider>)>;
 
 template <typename T>
-void CreateProviders(const std::string& prefix, int32_t numChannels,
+void CreateProviders(std::string_view prefix, int32_t numChannels,
                      WSRegisterFunc webRegisterFunc);
 
 template <typename T>
-void CreateSingleProvider(const std::string& key,
-                          WSRegisterFunc webRegisterFunc);
+void CreateSingleProvider(std::string_view key, WSRegisterFunc webRegisterFunc);
 
 }  // namespace wpilibws
 
diff --git a/simulation/halsim_ws_core/src/main/native/include/WSHalProviders.inc b/simulation/halsim_ws_core/src/main/native/include/WSHalProviders.inc
index df67764104..c9ce9d14d8 100644
--- a/simulation/halsim_ws_core/src/main/native/include/WSHalProviders.inc
+++ b/simulation/halsim_ws_core/src/main/native/include/WSHalProviders.inc
@@ -5,25 +5,27 @@
 #pragma once
 
 #include <memory>
-#include <string>
+#include <string_view>
 #include <utility>
 
+#include <fmt/format.h>
+
 #include "WSHalProviders.h"
 
 namespace wpilibws {
 
 template <typename T>
-void CreateProviders(const std::string& prefix, int numChannels,
+void CreateProviders(std::string_view prefix, int numChannels,
                      WSRegisterFunc webRegisterFunc) {
   for (int32_t i = 0; i < numChannels; i++) {
-    auto key = (prefix + "/" + wpi::Twine(i)).str();
+    auto key = fmt::format("{}/{}", prefix, i);
     auto ptr = std::make_unique<T>(i, key, prefix);
     webRegisterFunc(key, std::move(ptr));
   }
 }
 
 template <typename T>
-void CreateSingleProvider(const std::string& key,
+void CreateSingleProvider(std::string_view key,
                           WSRegisterFunc webRegisterFunc) {
   auto ptr = std::make_unique<T>(key, key);
   webRegisterFunc(key, std::move(ptr));
diff --git a/simulation/halsim_ws_core/src/main/native/include/WSProviderContainer.h b/simulation/halsim_ws_core/src/main/native/include/WSProviderContainer.h
index 6c51b46940..7c8f8617b5 100644
--- a/simulation/halsim_ws_core/src/main/native/include/WSProviderContainer.h
+++ b/simulation/halsim_ws_core/src/main/native/include/WSProviderContainer.h
@@ -8,6 +8,7 @@
 #include <memory>
 #include <mutex>
 #include <shared_mutex>
+#include <string_view>
 
 #include <wpi/StringMap.h>
 
@@ -25,12 +26,13 @@ class ProviderContainer {
   ProviderContainer(const ProviderContainer&) = delete;
   ProviderContainer& operator=(const ProviderContainer&) = delete;
 
-  void Add(wpi::StringRef key, std::shared_ptr<HALSimWSBaseProvider> provider) {
+  void Add(std::string_view key,
+           std::shared_ptr<HALSimWSBaseProvider> provider) {
     std::unique_lock lock(m_mutex);
     m_providers[key] = provider;
   }
 
-  void Delete(wpi::StringRef key) {
+  void Delete(std::string_view key) {
     std::unique_lock lock(m_mutex);
     m_providers.erase(key);
   }
@@ -42,7 +44,7 @@ class ProviderContainer {
     }
   }
 
-  ProviderPtr Get(wpi::StringRef key) {
+  ProviderPtr Get(std::string_view key) {
     std::shared_lock lock(m_mutex);
     auto fiter = m_providers.find(key);
     return fiter != m_providers.end() ? fiter->second : ProviderPtr();
diff --git a/simulation/halsim_ws_core/src/main/native/include/WSProvider_SimDevice.h b/simulation/halsim_ws_core/src/main/native/include/WSProvider_SimDevice.h
index 6d80467caf..c4d4347635 100644
--- a/simulation/halsim_ws_core/src/main/native/include/WSProvider_SimDevice.h
+++ b/simulation/halsim_ws_core/src/main/native/include/WSProvider_SimDevice.h
@@ -6,6 +6,7 @@
 
 #include <memory>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <hal/SimDevice.h>
@@ -34,9 +35,8 @@ struct SimDeviceValueData {
 
 class HALSimWSProviderSimDevice : public HALSimWSBaseProvider {
  public:
-  HALSimWSProviderSimDevice(HAL_SimDeviceHandle handle, const std::string& key,
-                            const std::string& type,
-                            const std::string& deviceId)
+  HALSimWSProviderSimDevice(HAL_SimDeviceHandle handle, std::string_view key,
+                            std::string_view type, std::string_view deviceId)
       : HALSimWSBaseProvider(key, type), m_handle(handle) {
     m_deviceId = deviceId;
   }
diff --git a/simulation/halsim_ws_server/src/dev/native/cpp/main.cpp b/simulation/halsim_ws_server/src/dev/native/cpp/main.cpp
index 4b03d40acb..d215df6837 100644
--- a/simulation/halsim_ws_server/src/dev/native/cpp/main.cpp
+++ b/simulation/halsim_ws_server/src/dev/native/cpp/main.cpp
@@ -2,14 +2,14 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
+#include <cstdio>
 #include <iostream>
 #include <thread>
 
+#include <fmt/format.h>
 #include <hal/DriverStation.h>
 #include <hal/HALBase.h>
 #include <hal/Main.h>
-#include <wpi/Format.h>
-#include <wpi/raw_ostream.h>
 
 extern "C" int HALSIM_InitExtension(void);
 
@@ -25,9 +25,9 @@ int main() {
   while (cycleCount < 1000) {
     std::this_thread::sleep_for(std::chrono::milliseconds(100));
     cycleCount++;
-    std::cout << "Count: " << cycleCount << std::endl;
+    fmt::print("Count: {}\n", cycleCount);
   }
 
-  std::cout << "DONE" << std::endl;
+  std::puts("DONE");
   HAL_ExitMain();
 }
diff --git a/simulation/halsim_ws_server/src/main/native/cpp/HALSimHttpConnection.cpp b/simulation/halsim_ws_server/src/main/native/cpp/HALSimHttpConnection.cpp
index d6967b47e9..3a2e3b2d24 100644
--- a/simulation/halsim_ws_server/src/main/native/cpp/HALSimHttpConnection.cpp
+++ b/simulation/halsim_ws_server/src/main/native/cpp/HALSimHttpConnection.cpp
@@ -6,12 +6,15 @@
 
 #include <uv.h>
 
+#include <string_view>
+
+#include <fmt/format.h>
 #include <wpi/MimeTypes.h>
 #include <wpi/SmallVector.h>
+#include <wpi/StringExtras.h>
 #include <wpi/UrlParser.h>
 #include <wpi/fs.h>
 #include <wpi/raw_istream.h>
-#include <wpi/raw_ostream.h>
 #include <wpi/raw_uv_ostream.h>
 #include <wpi/uv/Request.h>
 
@@ -19,7 +22,7 @@ namespace uv = wpi::uv;
 
 using namespace wpilibws;
 
-bool HALSimHttpConnection::IsValidWsUpgrade(wpi::StringRef protocol) {
+bool HALSimHttpConnection::IsValidWsUpgrade(std::string_view protocol) {
   if (m_request.GetUrl() != m_server->GetServerUri()) {
     MySendError(404, "invalid websocket address");
     return false;
@@ -29,7 +32,7 @@ bool HALSimHttpConnection::IsValidWsUpgrade(wpi::StringRef protocol) {
 }
 
 void HALSimHttpConnection::ProcessWsUpgrade() {
-  m_websocket->open.connect_extended([this](auto conn, wpi::StringRef) {
+  m_websocket->open.connect_extended([this](auto conn, auto) {
     conn.disconnect();  // one-shot
 
     if (!m_server->RegisterWebsocket(shared_from_this())) {
@@ -40,11 +43,11 @@ void HALSimHttpConnection::ProcessWsUpgrade() {
 
     Log(200);
     m_isWsConnected = true;
-    wpi::errs() << "HALWebSim: websocket connected\n";
+    std::fputs("HALWebSim: websocket connected\n", stderr);
   });
 
   // parse incoming JSON, dispatch to parent
-  m_websocket->text.connect([this](wpi::StringRef msg, bool) {
+  m_websocket->text.connect([this](auto msg, bool) {
     if (!m_isWsConnected) {
       return;
     }
@@ -61,10 +64,10 @@ void HALSimHttpConnection::ProcessWsUpgrade() {
     m_server->OnNetValueChanged(j);
   });
 
-  m_websocket->closed.connect([this](uint16_t, wpi::StringRef) {
+  m_websocket->closed.connect([this](uint16_t, auto) {
     // unset the global, allow another websocket to connect
     if (m_isWsConnected) {
-      wpi::errs() << "HALWebSim: websocket disconnected\n";
+      std::fputs("HALWebSim: websocket disconnected\n", stderr);
       m_isWsConnected = false;
 
       m_server->CloseWebsocket(shared_from_this());
@@ -91,30 +94,28 @@ void HALSimHttpConnection::OnSimValueChanged(const wpi::json& msg) {
                                   }
 
                                   if (err) {
-                                    wpi::errs() << err.str() << "\n";
-                                    wpi::errs().flush();
+                                    fmt::print(stderr, "{}\n", err.str());
+                                    std::fflush(stderr);
                                   }
                                 });
   });
 }
 
-void HALSimHttpConnection::SendFileResponse(int code,
-                                            const wpi::Twine& codeText,
-                                            const wpi::Twine& contentType,
-                                            const wpi::Twine& filename,
-                                            const wpi::Twine& extraHeader) {
-  std::string fn = filename.str();
+void HALSimHttpConnection::SendFileResponse(int code, std::string_view codeText,
+                                            std::string_view contentType,
+                                            std::string_view filename,
+                                            std::string_view extraHeader) {
   std::error_code ec;
 
   // get file size
-  auto size = fs::file_size(fn, ec);
+  auto size = fs::file_size(filename, ec);
   if (ec) {
     MySendError(404, "error getting file size");
     return;
   }
 
   // open file
-  wpi::raw_fd_istream is{fn, ec, true};
+  wpi::raw_fd_istream is{filename, ec, true};
   if (ec) {
     MySendError(404, "error opening file");
     return;
@@ -157,23 +158,23 @@ void HALSimHttpConnection::ProcessRequest() {
     return;
   }
 
-  wpi::StringRef path;
+  std::string_view path;
   if (url.HasPath()) {
     path = url.GetPath();
   }
 
-  if (m_request.GetMethod() == wpi::HTTP_GET && path.startswith("/") &&
-      !path.contains("..") && !path.contains("//")) {
+  if (m_request.GetMethod() == wpi::HTTP_GET && wpi::starts_with(path, '/') &&
+      !wpi::contains(path, "..") && !wpi::contains(path, "//")) {
     // convert to fs native representation
     fs::path nativePath;
-    if (path.startswith("/user/")) {
-      nativePath = fs::path{std::string{m_server->GetWebrootSys()}} /
-                   fs::path{std::string{path.drop_front(6)},
-                            fs::path::format::generic_format};
+    if (wpi::starts_with(path, "/user/")) {
+      nativePath =
+          fs::path{m_server->GetWebrootSys()} /
+          fs::path{wpi::drop_front(path, 6), fs::path::format::generic_format};
     } else {
-      nativePath = fs::path{std::string{m_server->GetWebrootSys()}} /
-                   fs::path{std::string{path.drop_front(1)},
-                            fs::path::format::generic_format};
+      nativePath =
+          fs::path{m_server->GetWebrootSys()} /
+          fs::path{wpi::drop_front(path, 1), fs::path::format::generic_format};
     }
 
     if (fs::is_directory(nativePath)) {
@@ -181,7 +182,7 @@ void HALSimHttpConnection::ProcessRequest() {
     }
 
     if (!fs::exists(nativePath) || fs::is_directory(nativePath)) {
-      MySendError(404, "Resource '" + path + "' not found");
+      MySendError(404, fmt::format("Resource '{}' not found", path));
     } else {
       auto contentType = wpi::MimeTypeFromPath(nativePath.string());
       SendFileResponse(200, "OK", contentType, nativePath.string());
@@ -191,14 +192,13 @@ void HALSimHttpConnection::ProcessRequest() {
   }
 }
 
-void HALSimHttpConnection::MySendError(int code, const wpi::Twine& message) {
+void HALSimHttpConnection::MySendError(int code, std::string_view message) {
   Log(code);
   SendError(code, message);
 }
 
 void HALSimHttpConnection::Log(int code) {
   auto method = wpi::http_method_str(m_request.GetMethod());
-  wpi::errs() << method << " " << m_request.GetUrl() << " HTTP/"
-              << m_request.GetMajor() << "." << m_request.GetMinor() << " "
-              << code << "\n";
+  fmt::print(stderr, "{} {} HTTP/{}.{} {}\n", method, m_request.GetUrl(),
+             m_request.GetMajor(), m_request.GetMinor(), code);
 }
diff --git a/simulation/halsim_ws_server/src/main/native/cpp/HALSimWeb.cpp b/simulation/halsim_ws_server/src/main/native/cpp/HALSimWeb.cpp
index 902916ef52..43e3b08962 100644
--- a/simulation/halsim_ws_server/src/main/native/cpp/HALSimWeb.cpp
+++ b/simulation/halsim_ws_server/src/main/native/cpp/HALSimWeb.cpp
@@ -4,8 +4,8 @@
 
 #include "HALSimWeb.h"
 
+#include <fmt/format.h>
 #include <wpi/SmallString.h>
-#include <wpi/Twine.h>
 #include <wpi/UrlParser.h>
 #include <wpi/WebSocketServer.h>
 #include <wpi/fs.h>
@@ -25,7 +25,7 @@ HALSimWeb::HALSimWeb(wpi::uv::Loop& loop, ProviderContainer& providers,
       m_providers(providers),
       m_simDevicesProvider(simDevicesProvider) {
   m_loop.error.connect([](uv::Error err) {
-    wpi::errs() << "HALSim WS Server libuv ERROR: " << err.str() << '\n';
+    fmt::print(stderr, "HALSim WS Server libuv ERROR: {}\n", err.str());
   });
 
   m_server = uv::Tcp::Create(m_loop);
@@ -70,7 +70,7 @@ bool HALSimWeb::Initialize() {
     try {
       m_port = std::stoi(port);
     } catch (const std::invalid_argument& err) {
-      wpi::errs() << "Error decoding HALSIMWS_PORT (" << err.what() << ")\n";
+      fmt::print(stderr, "Error decoding HALSIMWS_PORT ({})\n", err.what());
       return false;
     }
   } else {
@@ -98,8 +98,8 @@ void HALSimWeb::Start() {
 
   // start listening for incoming connections
   m_server->Listen();
-  wpi::outs() << "Listening at http://localhost:" << m_port << "\n";
-  wpi::outs() << "WebSocket URI: " << m_uri << "\n";
+  fmt::print("Listening at http://localhost:{}\n", m_port);
+  fmt::print("WebSocket URI: {}\n", m_uri);
 }
 
 bool HALSimWeb::RegisterWebsocket(
@@ -154,6 +154,6 @@ void HALSimWeb::OnNetValueChanged(const wpi::json& msg) {
       provider->OnNetValueChanged(msg.at("data"));
     }
   } catch (wpi::json::exception& e) {
-    wpi::errs() << "Error with incoming message: " << e.what() << "\n";
+    fmt::print(stderr, "Error with incoming message: {}\n", e.what());
   }
 }
diff --git a/simulation/halsim_ws_server/src/main/native/cpp/main.cpp b/simulation/halsim_ws_server/src/main/native/cpp/main.cpp
index 6cc5be813e..1ee0ae8bba 100644
--- a/simulation/halsim_ws_server/src/main/native/cpp/main.cpp
+++ b/simulation/halsim_ws_server/src/main/native/cpp/main.cpp
@@ -2,10 +2,10 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
+#include <cstdio>
 #include <memory>
 
 #include <hal/Extensions.h>
-#include <wpi/raw_ostream.h>
 
 #include "HALSimWSServer.h"
 
@@ -19,7 +19,7 @@ extern "C" {
 __declspec(dllexport)
 #endif
     int HALSIM_InitExtension(void) {
-  wpi::outs() << "Websocket WS Server Initializing.\n";
+  std::puts("Websocket WS Server Initializing.");
 
   HAL_OnShutdown(nullptr, [](void*) { gServer.reset(); });
 
@@ -28,7 +28,7 @@ __declspec(dllexport)
     return -1;
   }
 
-  wpi::outs() << "Websocket WS Server Initialized!\n";
+  std::puts("Websocket WS Server Initialized!");
   return 0;
 }
 }  // extern "C"
diff --git a/simulation/halsim_ws_server/src/main/native/include/HALSimHttpConnection.h b/simulation/halsim_ws_server/src/main/native/include/HALSimHttpConnection.h
index d6f65e5ad4..217e2ba4bb 100644
--- a/simulation/halsim_ws_server/src/main/native/include/HALSimHttpConnection.h
+++ b/simulation/halsim_ws_server/src/main/native/include/HALSimHttpConnection.h
@@ -6,6 +6,7 @@
 
 #include <cinttypes>
 #include <memory>
+#include <string_view>
 #include <utility>
 
 #include <HALSimBaseWebSocketConnection.h>
@@ -38,14 +39,13 @@ class HALSimHttpConnection
 
  protected:
   void ProcessRequest() override;
-  bool IsValidWsUpgrade(wpi::StringRef protocol) override;
+  bool IsValidWsUpgrade(std::string_view protocol) override;
   void ProcessWsUpgrade() override;
-  void SendFileResponse(int code, const wpi::Twine& codeText,
-                        const wpi::Twine& contentType,
-                        const wpi::Twine& filename,
-                        const wpi::Twine& extraHeader = wpi::Twine{});
+  void SendFileResponse(int code, std::string_view codeText,
+                        std::string_view contentType, std::string_view filename,
+                        std::string_view extraHeader = {});
 
-  void MySendError(int code, const wpi::Twine& message);
+  void MySendError(int code, std::string_view message);
   void Log(int code);
 
  private:
diff --git a/simulation/halsim_ws_server/src/main/native/include/HALSimWeb.h b/simulation/halsim_ws_server/src/main/native/include/HALSimWeb.h
index 3026b368bf..83a680e74f 100644
--- a/simulation/halsim_ws_server/src/main/native/include/HALSimWeb.h
+++ b/simulation/halsim_ws_server/src/main/native/include/HALSimWeb.h
@@ -11,7 +11,6 @@
 #include <WSBaseProvider.h>
 #include <WSProviderContainer.h>
 #include <WSProvider_SimDevice.h>
-#include <wpi/StringRef.h>
 #include <wpi/uv/Async.h>
 #include <wpi/uv/Loop.h>
 #include <wpi/uv/Tcp.h>
@@ -42,9 +41,9 @@ class HALSimWeb : public std::enable_shared_from_this<HALSimWeb> {
   // network -> sim
   void OnNetValueChanged(const wpi::json& msg);
 
-  wpi::StringRef GetWebrootSys() const { return m_webroot_sys; }
-  wpi::StringRef GetWebrootUser() const { return m_webroot_user; }
-  wpi::StringRef GetServerUri() const { return m_uri; }
+  const std::string& GetWebrootSys() const { return m_webroot_sys; }
+  const std::string& GetWebrootUser() const { return m_webroot_user; }
+  const std::string& GetServerUri() const { return m_uri; }
   int GetServerPort() const { return m_port; }
   wpi::uv::Loop& GetLoop() { return m_loop; }
 
diff --git a/simulation/halsim_ws_server/src/test/native/cpp/WebServerClientTest.cpp b/simulation/halsim_ws_server/src/test/native/cpp/WebServerClientTest.cpp
index 03469f3360..f13a0c65b3 100644
--- a/simulation/halsim_ws_server/src/test/native/cpp/WebServerClientTest.cpp
+++ b/simulation/halsim_ws_server/src/test/native/cpp/WebServerClientTest.cpp
@@ -4,10 +4,10 @@
 
 #include "WebServerClientTest.h"
 
-#include <sstream>
+#include <cstdio>
 
+#include <fmt/format.h>
 #include <wpi/SmallString.h>
-#include <wpi/raw_ostream.h>
 #include <wpi/raw_uv_ostream.h>
 #include <wpi/uv/util.h>
 
@@ -20,14 +20,12 @@ namespace wpilibws {
 // Create Web Socket and specify event callbacks
 void WebServerClientTest::InitializeWebSocket(const std::string& host, int port,
                                               const std::string& uri) {
-  std::stringstream ss;
-  ss << host << ":" << port;
-  wpi::outs() << "Will attempt to connect to: " << ss.str() << uri << "\n";
-  m_websocket =
-      wpi::WebSocket::CreateClient(*m_tcp_client.get(), uri, ss.str());
+  fmt::print("Will attempt to connect to: {}:{}{}\n", host, port, uri);
+  m_websocket = wpi::WebSocket::CreateClient(*m_tcp_client.get(), uri,
+                                             fmt::format("{}:{}", host, port));
 
   // Hook up events
-  m_websocket->open.connect_extended([this](auto conn, wpi::StringRef) {
+  m_websocket->open.connect_extended([this](auto conn, auto) {
     conn.disconnect();
     m_buffers = std::make_unique<BufferPool>();
 
@@ -38,17 +36,17 @@ void WebServerClientTest::InitializeWebSocket(const std::string& host, int port,
                                 });
 
     m_ws_connected = true;
-    wpi::errs() << "WebServerClientTest: WebSocket Connected\n";
+    std::fputs("WebServerClientTest: WebSocket Connected\n", stderr);
   });
 
-  m_websocket->text.connect([this](wpi::StringRef msg, bool) {
+  m_websocket->text.connect([this](auto msg, bool) {
     wpi::json j;
     try {
       j = wpi::json::parse(msg);
     } catch (const wpi::json::parse_error& e) {
       std::string err("JSON parse failed: ");
       err += e.what();
-      wpi::errs() << err << "\n";
+      fmt::print(stderr, "{}\n", err);
       m_websocket->Fail(1003, err);
       return;
     }
@@ -56,9 +54,9 @@ void WebServerClientTest::InitializeWebSocket(const std::string& host, int port,
     m_json = j;
   });
 
-  m_websocket->closed.connect([this](uint16_t, wpi::StringRef) {
+  m_websocket->closed.connect([this](uint16_t, auto) {
     if (m_ws_connected) {
-      wpi::errs() << "WebServerClientTest: Websocket Disconnected\n";
+      std::fputs("WebServerClientTest: Websocket Disconnected\n", stderr);
       m_ws_connected = false;
     }
   });
@@ -67,11 +65,11 @@ void WebServerClientTest::InitializeWebSocket(const std::string& host, int port,
 // Create tcp client, specify callbacks, and create timers for loop
 bool WebServerClientTest::Initialize() {
   m_loop.error.connect(
-      [](uv::Error err) { wpi::errs() << "uv Error: " << err.str() << "\n"; });
+      [](uv::Error err) { fmt::print(stderr, "uv Error: {}\n", err.str()); });
 
   m_tcp_client = uv::Tcp::Create(m_loop);
   if (!m_tcp_client) {
-    wpi::errs() << "ERROR: Could not create TCP Client\n";
+    std::fputs("ERROR: Could not create TCP Client\n", stderr);
     return false;
   }
 
@@ -90,7 +88,7 @@ bool WebServerClientTest::Initialize() {
       });
 
   m_tcp_client->closed.connect(
-      []() { wpi::errs() << "TCP connection closed\n"; });
+      []() { std::fputs("TCP connection closed\n", stderr); });
 
   // Set up the connection timer
   m_connect_timer = uv::Timer::Create(m_loop);
@@ -101,18 +99,17 @@ bool WebServerClientTest::Initialize() {
   m_connect_timer->timeout.connect([this] { AttemptConnect(); });
   m_connect_timer->Start(uv::Timer::Time(0));
 
-  wpi::outs() << "WebServerClientTest Initialized\n";
+  std::puts("WebServerClientTest Initialized");
 
   return true;
 }
 
 void WebServerClientTest::AttemptConnect() {
   m_connect_attempts++;
-  wpi::outs() << "Test Client Connection Attempt " << m_connect_attempts
-              << "\n";
+  fmt::print("Test Client Connection Attempt {}\n", m_connect_attempts);
 
   if (m_connect_attempts >= 5) {
-    wpi::errs() << "Test Client Timeout. Unable to connect\n";
+    std::fputs("Test Client Timeout. Unable to connect\n", stderr);
     m_loop.Stop();
     return;
   }
@@ -127,7 +124,7 @@ void WebServerClientTest::AttemptConnect() {
 
 void WebServerClientTest::SendMessage(const wpi::json& msg) {
   if (msg.empty()) {
-    wpi::errs() << "Message to send is empty\n";
+    std::fputs("Message to send is empty\n", stderr);
     return;
   }
 
@@ -147,8 +144,8 @@ void WebServerClientTest::SendMessage(const wpi::json& msg) {
         m_buffers->Release(bufs);
       }
       if (err) {
-        wpi::errs() << err.str() << "\n";
-        wpi::errs().flush();
+        fmt::print(stderr, "{}\n", err.str());
+        std::fflush(stderr);
       }
     });
   });
diff --git a/simulation/halsim_ws_server/src/test/native/cpp/main.cpp b/simulation/halsim_ws_server/src/test/native/cpp/main.cpp
index 0b4628e462..ef31ba1fb8 100644
--- a/simulation/halsim_ws_server/src/test/native/cpp/main.cpp
+++ b/simulation/halsim_ws_server/src/test/native/cpp/main.cpp
@@ -4,11 +4,11 @@
 
 #include <thread>
 
+#include <fmt/format.h>
 #include <hal/DriverStation.h>
 #include <hal/HALBase.h>
 #include <hal/Main.h>
 #include <hal/simulation/DIOData.h>
-#include <wpi/raw_ostream.h>
 #include <wpi/uv/Loop.h>
 
 #include "HALSimWSServer.h"
@@ -55,8 +55,8 @@ TEST_F(WebServerIntegrationTest, DISABLED_DigitalOutput) {
         return;
       }
       if (IsConnectedClientWS()) {
-        wpi::outs() << "***** Setting DIO value for pin " << PIN << " to "
-                    << (EXPECTED_VALUE ? "true" : "false") << "\n";
+        fmt::print("***** Setting DIO value for pin {} to {}\n", PIN,
+                   (EXPECTED_VALUE ? "true" : "false"));
         HALSIM_SetDIOValue(PIN, EXPECTED_VALUE);
         done = true;
       }
@@ -83,7 +83,7 @@ TEST_F(WebServerIntegrationTest, DISABLED_DigitalOutput) {
       test_value = it.value();
     }
   } catch (wpi::json::exception& e) {
-    wpi::errs() << "Error with incoming message: " << e.what() << "\n";
+    fmt::print(stderr, "Error with incoming message: {}\n", e.what());
   }
 
   // Compare results
@@ -109,7 +109,7 @@ TEST_F(WebServerIntegrationTest, DISABLED_DigitalInput) {
         wpi::json msg = {{"type", "DIO"},
                          {"device", std::to_string(PIN)},
                          {"data", {{"<>value", EXPECTED_VALUE}}}};
-        wpi::outs() << "***** Input JSON: " << msg.dump() << "\n";
+        fmt::print("***** Input JSON: {}\n", msg.dump());
         m_webserverClient->SendMessage(msg);
         done = true;
       }
@@ -144,7 +144,7 @@ TEST_F(WebServerIntegrationTest, DriverStation) {
             {"type", "DriverStation"},
             {"device", ""},
             {"data", {{">enabled", EXPECTED_VALUE}, {">new_data", true}}}};
-        wpi::outs() << "***** Input JSON: " << msg.dump() << "\n";
+        fmt::print("***** Input JSON: {}\n", msg.dump());
         m_webserverClient->SendMessage(msg);
         done = true;
       }
diff --git a/wpigui/src/main/native/include/wpigui.h b/wpigui/src/main/native/include/wpigui.h
index 228f89d3ed..7860f0debd 100644
--- a/wpigui/src/main/native/include/wpigui.h
+++ b/wpigui/src/main/native/include/wpigui.h
@@ -6,14 +6,10 @@
 
 #include <functional>
 #include <string>
+#include <string_view>
 
 #include <imgui.h>
 
-#if __has_include(<wpi/StringRef.h>)
-#include <wpi/StringRef.h>
-#define WPIGUI_HAS_STRINGREF
-#endif
-
 extern "C" struct GLFWwindow;
 
 namespace wpi::gui {
@@ -98,11 +94,10 @@ GLFWwindow* GetSystemWindow();
  */
 bool AddIcon(const unsigned char* data, int len);
 
-#ifdef WPIGUI_HAS_STRINGREF
-inline bool AddIcon(wpi::StringRef data) {
-  return AddIcon(data.bytes_begin(), data.size());
+inline bool AddIcon(std::string_view data) {
+  return AddIcon(reinterpret_cast<const unsigned char*>(data.data()),
+                 data.size());
 }
-#endif
 
 /**
  * Adds a font to the GUI.  The passed function is called during
diff --git a/wpilibNewCommands/src/main/native/cpp/frc2/command/CommandScheduler.cpp b/wpilibNewCommands/src/main/native/cpp/frc2/command/CommandScheduler.cpp
index c51ad2ed2b..f269698dfe 100644
--- a/wpilibNewCommands/src/main/native/cpp/frc2/command/CommandScheduler.cpp
+++ b/wpilibNewCommands/src/main/native/cpp/frc2/command/CommandScheduler.cpp
@@ -4,6 +4,8 @@
 
 #include "frc2/command/CommandScheduler.h"
 
+#include <cstdio>
+
 #include <frc/RobotBase.h>
 #include <frc/RobotState.h>
 #include <frc/TimedRobot.h>
@@ -15,7 +17,6 @@
 #include <networktables/NetworkTableEntry.h>
 #include <wpi/DenseMap.h>
 #include <wpi/SmallVector.h>
-#include <wpi/raw_ostream.h>
 
 #include "frc2/command/CommandGroupBase.h"
 #include "frc2/command/CommandState.h"
@@ -65,7 +66,7 @@ static bool ContainsKey(const TMap& map, TKey keyToCheck) {
 
 CommandScheduler::CommandScheduler()
     : m_impl(new Impl), m_watchdog(frc::TimedRobot::kDefaultPeriod, [] {
-        wpi::outs() << "CommandScheduler loop time overrun.\n";
+        std::puts("CommandScheduler loop time overrun.");
       }) {
   HAL_Report(HALUsageReporting::kResourceType_Command,
              HALUsageReporting::kCommand2_Scheduler);
diff --git a/wpilibNewCommands/src/main/native/cpp/frc2/command/PrintCommand.cpp b/wpilibNewCommands/src/main/native/cpp/frc2/command/PrintCommand.cpp
index af711aadc1..8d7c855602 100644
--- a/wpilibNewCommands/src/main/native/cpp/frc2/command/PrintCommand.cpp
+++ b/wpilibNewCommands/src/main/native/cpp/frc2/command/PrintCommand.cpp
@@ -4,13 +4,13 @@
 
 #include "frc2/command/PrintCommand.h"
 
-#include <wpi/raw_ostream.h>
+#include <fmt/format.h>
 
 using namespace frc2;
 
 PrintCommand::PrintCommand(std::string_view message)
-    : CommandHelper{
-          [str = std::string(message)] { wpi::outs() << str << "\n"; }, {}} {}
+    : CommandHelper{[str = std::string(message)] { fmt::print("{}\n", str); },
+                    {}} {}
 
 bool PrintCommand::RunsWhenDisabled() const {
   return true;
diff --git a/wpilibOldCommands/src/main/native/cpp/commands/PrintCommand.cpp b/wpilibOldCommands/src/main/native/cpp/commands/PrintCommand.cpp
index 3589feea2d..ca8f49a84a 100644
--- a/wpilibOldCommands/src/main/native/cpp/commands/PrintCommand.cpp
+++ b/wpilibOldCommands/src/main/native/cpp/commands/PrintCommand.cpp
@@ -5,7 +5,6 @@
 #include "frc/commands/PrintCommand.h"
 
 #include <fmt/format.h>
-#include <wpi/raw_ostream.h>
 
 using namespace frc;
 
@@ -15,5 +14,5 @@ PrintCommand::PrintCommand(std::string_view message)
 }
 
 void PrintCommand::Initialize() {
-  wpi::outs() << m_message << '\n';
+  fmt::print("{}\n", m_message);
 }
diff --git a/wpilibc/src/main/native/cpp/DoubleSolenoid.cpp b/wpilibc/src/main/native/cpp/DoubleSolenoid.cpp
index 12fda75d1c..bae03c7d02 100644
--- a/wpilibc/src/main/native/cpp/DoubleSolenoid.cpp
+++ b/wpilibc/src/main/native/cpp/DoubleSolenoid.cpp
@@ -121,7 +121,7 @@ void DoubleSolenoid::InitSendable(SendableBuilder& builder) {
   builder.SetSafeState([=]() { Set(kOff); });
   builder.AddSmallStringProperty(
       "Value",
-      [=](wpi::SmallVectorImpl<char>& buf) -> wpi::StringRef {
+      [=](wpi::SmallVectorImpl<char>& buf) -> std::string_view {
         switch (Get()) {
           case kForward:
             return "Forward";
@@ -131,7 +131,7 @@ void DoubleSolenoid::InitSendable(SendableBuilder& builder) {
             return "Off";
         }
       },
-      [=](wpi::StringRef value) {
+      [=](std::string_view value) {
         Value lvalue = kOff;
         if (value == "Forward") {
           lvalue = kForward;
diff --git a/wpilibc/src/main/native/cpp/IterativeRobotBase.cpp b/wpilibc/src/main/native/cpp/IterativeRobotBase.cpp
index 6202e5bff0..2033745c60 100644
--- a/wpilibc/src/main/native/cpp/IterativeRobotBase.cpp
+++ b/wpilibc/src/main/native/cpp/IterativeRobotBase.cpp
@@ -4,9 +4,9 @@
 
 #include "frc/IterativeRobotBase.h"
 
+#include <fmt/format.h>
 #include <hal/DriverStation.h>
 #include <networktables/NetworkTableInstance.h>
-#include <wpi/raw_ostream.h>
 
 #include "frc/Errors.h"
 #include "frc/livewindow/LiveWindow.h"
@@ -23,33 +23,33 @@ IterativeRobotBase::IterativeRobotBase(units::second_t period)
       m_watchdog(period, [this] { PrintLoopOverrunMessage(); }) {}
 
 void IterativeRobotBase::RobotInit() {
-  wpi::outs() << "Default " << __FUNCTION__ << "() method... Override me!\n";
+  fmt::print("Default {}() method... Override me!\n", __FUNCTION__);
 }
 
 void IterativeRobotBase::SimulationInit() {
-  wpi::outs() << "Default " << __FUNCTION__ << "() method... Override me!\n";
+  fmt::print("Default {}() method... Override me!\n", __FUNCTION__);
 }
 
 void IterativeRobotBase::DisabledInit() {
-  wpi::outs() << "Default " << __FUNCTION__ << "() method... Override me!\n";
+  fmt::print("Default {}() method... Override me!\n", __FUNCTION__);
 }
 
 void IterativeRobotBase::AutonomousInit() {
-  wpi::outs() << "Default " << __FUNCTION__ << "() method... Override me!\n";
+  fmt::print("Default {}() method... Override me!\n", __FUNCTION__);
 }
 
 void IterativeRobotBase::TeleopInit() {
-  wpi::outs() << "Default " << __FUNCTION__ << "() method... Override me!\n";
+  fmt::print("Default {}() method... Override me!\n", __FUNCTION__);
 }
 
 void IterativeRobotBase::TestInit() {
-  wpi::outs() << "Default " << __FUNCTION__ << "() method... Override me!\n";
+  fmt::print("Default {}() method... Override me!\n", __FUNCTION__);
 }
 
 void IterativeRobotBase::RobotPeriodic() {
   static bool firstRun = true;
   if (firstRun) {
-    wpi::outs() << "Default " << __FUNCTION__ << "() method... Override me!\n";
+    fmt::print("Default {}() method... Override me!\n", __FUNCTION__);
     firstRun = false;
   }
 }
@@ -57,7 +57,7 @@ void IterativeRobotBase::RobotPeriodic() {
 void IterativeRobotBase::SimulationPeriodic() {
   static bool firstRun = true;
   if (firstRun) {
-    wpi::outs() << "Default " << __FUNCTION__ << "() method... Override me!\n";
+    fmt::print("Default {}() method... Override me!\n", __FUNCTION__);
     firstRun = false;
   }
 }
@@ -65,7 +65,7 @@ void IterativeRobotBase::SimulationPeriodic() {
 void IterativeRobotBase::DisabledPeriodic() {
   static bool firstRun = true;
   if (firstRun) {
-    wpi::outs() << "Default " << __FUNCTION__ << "() method... Override me!\n";
+    fmt::print("Default {}() method... Override me!\n", __FUNCTION__);
     firstRun = false;
   }
 }
@@ -73,7 +73,7 @@ void IterativeRobotBase::DisabledPeriodic() {
 void IterativeRobotBase::AutonomousPeriodic() {
   static bool firstRun = true;
   if (firstRun) {
-    wpi::outs() << "Default " << __FUNCTION__ << "() method... Override me!\n";
+    fmt::print("Default {}() method... Override me!\n", __FUNCTION__);
     firstRun = false;
   }
 }
@@ -81,7 +81,7 @@ void IterativeRobotBase::AutonomousPeriodic() {
 void IterativeRobotBase::TeleopPeriodic() {
   static bool firstRun = true;
   if (firstRun) {
-    wpi::outs() << "Default " << __FUNCTION__ << "() method... Override me!\n";
+    fmt::print("Default {}() method... Override me!\n", __FUNCTION__);
     firstRun = false;
   }
 }
@@ -89,7 +89,7 @@ void IterativeRobotBase::TeleopPeriodic() {
 void IterativeRobotBase::TestPeriodic() {
   static bool firstRun = true;
   if (firstRun) {
-    wpi::outs() << "Default " << __FUNCTION__ << "() method... Override me!\n";
+    fmt::print("Default {}() method... Override me!\n", __FUNCTION__);
     firstRun = false;
   }
 }
diff --git a/wpilibc/src/main/native/cpp/Preferences.cpp b/wpilibc/src/main/native/cpp/Preferences.cpp
index ca38900733..ae8c578514 100644
--- a/wpilibc/src/main/native/cpp/Preferences.cpp
+++ b/wpilibc/src/main/native/cpp/Preferences.cpp
@@ -8,12 +8,11 @@
 
 #include <hal/FRCUsageReporting.h>
 #include <networktables/NetworkTableInstance.h>
-#include <wpi/StringRef.h>
 
 using namespace frc;
 
 // The Preferences table name
-static wpi::StringRef kTableName{"Preferences"};
+static constexpr std::string_view kTableName{"Preferences"};
 
 Preferences* Preferences::GetInstance() {
   static Preferences instance;
@@ -24,126 +23,126 @@ std::vector<std::string> Preferences::GetKeys() {
   return m_table->GetKeys();
 }
 
-std::string Preferences::GetString(wpi::StringRef key,
-                                   wpi::StringRef defaultValue) {
+std::string Preferences::GetString(std::string_view key,
+                                   std::string_view defaultValue) {
   return m_table->GetString(key, defaultValue);
 }
 
-int Preferences::GetInt(wpi::StringRef key, int defaultValue) {
+int Preferences::GetInt(std::string_view key, int defaultValue) {
   return static_cast<int>(m_table->GetNumber(key, defaultValue));
 }
 
-double Preferences::GetDouble(wpi::StringRef key, double defaultValue) {
+double Preferences::GetDouble(std::string_view key, double defaultValue) {
   return m_table->GetNumber(key, defaultValue);
 }
 
-float Preferences::GetFloat(wpi::StringRef key, float defaultValue) {
+float Preferences::GetFloat(std::string_view key, float defaultValue) {
   return m_table->GetNumber(key, defaultValue);
 }
 
-bool Preferences::GetBoolean(wpi::StringRef key, bool defaultValue) {
+bool Preferences::GetBoolean(std::string_view key, bool defaultValue) {
   return m_table->GetBoolean(key, defaultValue);
 }
 
-int64_t Preferences::GetLong(wpi::StringRef key, int64_t defaultValue) {
+int64_t Preferences::GetLong(std::string_view key, int64_t defaultValue) {
   return static_cast<int64_t>(m_table->GetNumber(key, defaultValue));
 }
 
-void Preferences::SetString(wpi::StringRef key, wpi::StringRef value) {
+void Preferences::SetString(std::string_view key, std::string_view value) {
   auto entry = m_table->GetEntry(key);
   entry.SetString(value);
   entry.SetPersistent();
 }
 
-void Preferences::PutString(wpi::StringRef key, wpi::StringRef value) {
+void Preferences::PutString(std::string_view key, std::string_view value) {
   SetString(key, value);
 }
 
-void Preferences::InitString(wpi::StringRef key, wpi::StringRef value) {
+void Preferences::InitString(std::string_view key, std::string_view value) {
   auto entry = m_table->GetEntry(key);
   entry.SetDefaultString(value);
 }
 
-void Preferences::SetInt(wpi::StringRef key, int value) {
+void Preferences::SetInt(std::string_view key, int value) {
   auto entry = m_table->GetEntry(key);
   entry.SetDouble(value);
   entry.SetPersistent();
 }
 
-void Preferences::PutInt(wpi::StringRef key, int value) {
+void Preferences::PutInt(std::string_view key, int value) {
   SetInt(key, value);
 }
 
-void Preferences::InitInt(wpi::StringRef key, int value) {
+void Preferences::InitInt(std::string_view key, int value) {
   auto entry = m_table->GetEntry(key);
   entry.SetDefaultDouble(value);
 }
 
-void Preferences::SetDouble(wpi::StringRef key, double value) {
+void Preferences::SetDouble(std::string_view key, double value) {
   auto entry = m_table->GetEntry(key);
   entry.SetDouble(value);
   entry.SetPersistent();
 }
 
-void Preferences::PutDouble(wpi::StringRef key, double value) {
+void Preferences::PutDouble(std::string_view key, double value) {
   SetDouble(key, value);
 }
 
-void Preferences::InitDouble(wpi::StringRef key, double value) {
+void Preferences::InitDouble(std::string_view key, double value) {
   auto entry = m_table->GetEntry(key);
   entry.SetDefaultDouble(value);
 }
 
-void Preferences::SetFloat(wpi::StringRef key, float value) {
+void Preferences::SetFloat(std::string_view key, float value) {
   auto entry = m_table->GetEntry(key);
   entry.SetDouble(value);
   entry.SetPersistent();
 }
 
-void Preferences::PutFloat(wpi::StringRef key, float value) {
+void Preferences::PutFloat(std::string_view key, float value) {
   SetFloat(key, value);
 }
 
-void Preferences::InitFloat(wpi::StringRef key, float value) {
+void Preferences::InitFloat(std::string_view key, float value) {
   auto entry = m_table->GetEntry(key);
   entry.SetDefaultDouble(value);
 }
 
-void Preferences::SetBoolean(wpi::StringRef key, bool value) {
+void Preferences::SetBoolean(std::string_view key, bool value) {
   auto entry = m_table->GetEntry(key);
   entry.SetBoolean(value);
   entry.SetPersistent();
 }
 
-void Preferences::PutBoolean(wpi::StringRef key, bool value) {
+void Preferences::PutBoolean(std::string_view key, bool value) {
   SetBoolean(key, value);
 }
 
-void Preferences::InitBoolean(wpi::StringRef key, bool value) {
+void Preferences::InitBoolean(std::string_view key, bool value) {
   auto entry = m_table->GetEntry(key);
   entry.SetDefaultBoolean(value);
 }
 
-void Preferences::SetLong(wpi::StringRef key, int64_t value) {
+void Preferences::SetLong(std::string_view key, int64_t value) {
   auto entry = m_table->GetEntry(key);
   entry.SetDouble(value);
   entry.SetPersistent();
 }
 
-void Preferences::PutLong(wpi::StringRef key, int64_t value) {
+void Preferences::PutLong(std::string_view key, int64_t value) {
   SetLong(key, value);
 }
 
-void Preferences::InitLong(wpi::StringRef key, int64_t value) {
+void Preferences::InitLong(std::string_view key, int64_t value) {
   auto entry = m_table->GetEntry(key);
   entry.SetDefaultDouble(value);
 }
 
-bool Preferences::ContainsKey(wpi::StringRef key) {
+bool Preferences::ContainsKey(std::string_view key) {
   return m_table->ContainsKey(key);
 }
 
-void Preferences::Remove(wpi::StringRef key) {
+void Preferences::Remove(std::string_view key) {
   m_table->Delete(key);
 }
 
@@ -159,7 +158,7 @@ Preferences::Preferences()
     : m_table(nt::NetworkTableInstance::GetDefault().GetTable(kTableName)) {
   m_table->GetEntry(".type").SetString("RobotPreferences");
   m_listener = m_table->AddEntryListener(
-      [=](nt::NetworkTable* table, wpi::StringRef name,
+      [=](nt::NetworkTable* table, std::string_view name,
           nt::NetworkTableEntry entry, std::shared_ptr<nt::Value> value,
           int flags) { entry.SetPersistent(); },
       NT_NOTIFY_NEW | NT_NOTIFY_IMMEDIATE);
diff --git a/wpilibc/src/main/native/cpp/Relay.cpp b/wpilibc/src/main/native/cpp/Relay.cpp
index b925f7d384..887be6fee3 100644
--- a/wpilibc/src/main/native/cpp/Relay.cpp
+++ b/wpilibc/src/main/native/cpp/Relay.cpp
@@ -178,7 +178,7 @@ void Relay::InitSendable(SendableBuilder& builder) {
   builder.SetSafeState([=]() { Set(kOff); });
   builder.AddSmallStringProperty(
       "Value",
-      [=](wpi::SmallVectorImpl<char>& buf) -> wpi::StringRef {
+      [=](wpi::SmallVectorImpl<char>& buf) -> std::string_view {
         switch (Get()) {
           case kOn:
             return "On";
@@ -190,7 +190,7 @@ void Relay::InitSendable(SendableBuilder& builder) {
             return "Off";
         }
       },
-      [=](wpi::StringRef value) {
+      [=](std::string_view value) {
         if (value == "Off") {
           Set(kOff);
         } else if (value == "Forward") {
diff --git a/wpilibc/src/main/native/cpp/Tracer.cpp b/wpilibc/src/main/native/cpp/Tracer.cpp
index 9aa0116f16..1375411ff1 100644
--- a/wpilibc/src/main/native/cpp/Tracer.cpp
+++ b/wpilibc/src/main/native/cpp/Tracer.cpp
@@ -4,7 +4,7 @@
 
 #include "frc/Tracer.h"
 
-#include <wpi/Format.h>
+#include <fmt/format.h>
 #include <wpi/SmallString.h>
 #include <wpi/raw_ostream.h>
 
@@ -25,7 +25,7 @@ void Tracer::ClearEpochs() {
   m_epochs.clear();
 }
 
-void Tracer::AddEpoch(wpi::StringRef epochName) {
+void Tracer::AddEpoch(std::string_view epochName) {
   auto currentTime = hal::fpga_clock::now();
   m_epochs[epochName] = currentTime - m_startTime;
   m_startTime = currentTime;
@@ -48,11 +48,9 @@ void Tracer::PrintEpochs(wpi::raw_ostream& os) {
   if (now - m_lastEpochsPrintTime > kMinPrintPeriod) {
     m_lastEpochsPrintTime = now;
     for (const auto& epoch : m_epochs) {
-      os << '\t' << epoch.getKey() << ": "
-         << wpi::format(
-                "%.6f",
-                duration_cast<microseconds>(epoch.getValue()).count() / 1.0e6)
-         << "s\n";
+      os << fmt::format(
+          "\t{}: {:.6f}s\n", epoch.getKey(),
+          duration_cast<microseconds>(epoch.getValue()).count() / 1.0e6);
     }
   }
 }
diff --git a/wpilibc/src/main/native/cpp/Watchdog.cpp b/wpilibc/src/main/native/cpp/Watchdog.cpp
index e6eac6a8cf..8fbfe81f71 100644
--- a/wpilibc/src/main/native/cpp/Watchdog.cpp
+++ b/wpilibc/src/main/native/cpp/Watchdog.cpp
@@ -192,7 +192,7 @@ bool Watchdog::IsExpired() const {
   return m_isExpired;
 }
 
-void Watchdog::AddEpoch(wpi::StringRef epochName) {
+void Watchdog::AddEpoch(std::string_view epochName) {
   m_tracer.AddEpoch(epochName);
 }
 
diff --git a/wpilibc/src/main/native/cpp/shuffleboard/LayoutType.cpp b/wpilibc/src/main/native/cpp/shuffleboard/LayoutType.cpp
index 9b812d41e5..9c47efb8e9 100644
--- a/wpilibc/src/main/native/cpp/shuffleboard/LayoutType.cpp
+++ b/wpilibc/src/main/native/cpp/shuffleboard/LayoutType.cpp
@@ -6,6 +6,6 @@
 
 using namespace frc;
 
-wpi::StringRef LayoutType::GetLayoutName() const {
+std::string_view LayoutType::GetLayoutName() const {
   return m_layoutName;
 }
diff --git a/wpilibc/src/main/native/cpp/shuffleboard/RecordingController.cpp b/wpilibc/src/main/native/cpp/shuffleboard/RecordingController.cpp
index ecdf977d72..834c4be88d 100644
--- a/wpilibc/src/main/native/cpp/shuffleboard/RecordingController.cpp
+++ b/wpilibc/src/main/native/cpp/shuffleboard/RecordingController.cpp
@@ -26,7 +26,7 @@ void RecordingController::StopRecording() {
   m_recordingControlEntry.SetBoolean(false);
 }
 
-void RecordingController::SetRecordingFileNameFormat(wpi::StringRef format) {
+void RecordingController::SetRecordingFileNameFormat(std::string_view format) {
   m_recordingFileNameFormatEntry.SetString(format);
 }
 
@@ -35,7 +35,7 @@ void RecordingController::ClearRecordingFileNameFormat() {
 }
 
 void RecordingController::AddEventMarker(
-    wpi::StringRef name, wpi::StringRef description,
+    std::string_view name, std::string_view description,
     ShuffleboardEventImportance importance) {
   if (name.empty()) {
     FRC_ReportError(err::Error, "{}",
@@ -43,5 +43,6 @@ void RecordingController::AddEventMarker(
     return;
   }
   m_eventsTable->GetSubTable(name)->GetEntry("Info").SetStringArray(
-      {description, ShuffleboardEventImportanceName(importance)});
+      {std::string{description},
+       std::string{ShuffleboardEventImportanceName(importance)}});
 }
diff --git a/wpilibc/src/main/native/cpp/shuffleboard/Shuffleboard.cpp b/wpilibc/src/main/native/cpp/shuffleboard/Shuffleboard.cpp
index 7c7e535151..16b404c255 100644
--- a/wpilibc/src/main/native/cpp/shuffleboard/Shuffleboard.cpp
+++ b/wpilibc/src/main/native/cpp/shuffleboard/Shuffleboard.cpp
@@ -14,7 +14,7 @@ void Shuffleboard::Update() {
   GetInstance().Update();
 }
 
-ShuffleboardTab& Shuffleboard::GetTab(wpi::StringRef title) {
+ShuffleboardTab& Shuffleboard::GetTab(std::string_view title) {
   return GetInstance().GetTab(title);
 }
 
@@ -22,7 +22,7 @@ void Shuffleboard::SelectTab(int index) {
   GetInstance().SelectTab(index);
 }
 
-void Shuffleboard::SelectTab(wpi::StringRef title) {
+void Shuffleboard::SelectTab(std::string_view title) {
   GetInstance().SelectTab(title);
 }
 
@@ -44,7 +44,7 @@ void Shuffleboard::StopRecording() {
   GetRecordingController().StopRecording();
 }
 
-void Shuffleboard::SetRecordingFileNameFormat(wpi::StringRef format) {
+void Shuffleboard::SetRecordingFileNameFormat(std::string_view format) {
   GetRecordingController().SetRecordingFileNameFormat(format);
 }
 
@@ -52,13 +52,13 @@ void Shuffleboard::ClearRecordingFileNameFormat() {
   GetRecordingController().ClearRecordingFileNameFormat();
 }
 
-void Shuffleboard::AddEventMarker(wpi::StringRef name,
-                                  wpi::StringRef description,
+void Shuffleboard::AddEventMarker(std::string_view name,
+                                  std::string_view description,
                                   ShuffleboardEventImportance importance) {
   GetRecordingController().AddEventMarker(name, description, importance);
 }
 
-void Shuffleboard::AddEventMarker(wpi::StringRef name,
+void Shuffleboard::AddEventMarker(std::string_view name,
                                   ShuffleboardEventImportance importance) {
   AddEventMarker(name, "", importance);
 }
diff --git a/wpilibc/src/main/native/cpp/shuffleboard/ShuffleboardContainer.cpp b/wpilibc/src/main/native/cpp/shuffleboard/ShuffleboardContainer.cpp
index d1d49b889c..bf36ea66fb 100644
--- a/wpilibc/src/main/native/cpp/shuffleboard/ShuffleboardContainer.cpp
+++ b/wpilibc/src/main/native/cpp/shuffleboard/ShuffleboardContainer.cpp
@@ -4,8 +4,6 @@
 
 #include "frc/shuffleboard/ShuffleboardContainer.h"
 
-#include <wpi/raw_ostream.h>
-
 #include "frc/Errors.h"
 #include "frc/shuffleboard/ComplexWidget.h"
 #include "frc/shuffleboard/ShuffleboardComponent.h"
@@ -70,7 +68,7 @@ ComplexWidget& ShuffleboardContainer::Add(std::string_view title,
 ComplexWidget& ShuffleboardContainer::Add(Sendable& sendable) {
   auto name = SendableRegistry::GetInstance().GetName(&sendable);
   if (name.empty()) {
-    wpi::outs() << "Sendable must have a name\n";
+    FRC_ReportError(err::Error, "{}", "Sendable must have a name");
   }
   return Add(name, sendable);
 }
@@ -285,7 +283,7 @@ void ShuffleboardContainer::DisableIfActuator() {
 void ShuffleboardContainer::CheckTitle(std::string_view title) {
   std::string titleStr{title};
   if (m_usedTitles.count(titleStr) > 0) {
-    wpi::errs() << "Title is already in use: " << title << "\n";
+    FRC_ReportError(err::Error, "Title is already in use: {}", title);
     return;
   }
   m_usedTitles.insert(titleStr);
diff --git a/wpilibc/src/main/native/cpp/shuffleboard/ShuffleboardInstance.cpp b/wpilibc/src/main/native/cpp/shuffleboard/ShuffleboardInstance.cpp
index 25daba291f..fb4485b269 100644
--- a/wpilibc/src/main/native/cpp/shuffleboard/ShuffleboardInstance.cpp
+++ b/wpilibc/src/main/native/cpp/shuffleboard/ShuffleboardInstance.cpp
@@ -31,7 +31,7 @@ ShuffleboardInstance::ShuffleboardInstance(nt::NetworkTableInstance ntInstance)
 
 ShuffleboardInstance::~ShuffleboardInstance() = default;
 
-frc::ShuffleboardTab& ShuffleboardInstance::GetTab(wpi::StringRef title) {
+frc::ShuffleboardTab& ShuffleboardInstance::GetTab(std::string_view title) {
   if (m_impl->tabs.find(title) == m_impl->tabs.end()) {
     m_impl->tabs.try_emplace(title, ShuffleboardTab(*this, title));
     m_impl->tabsChanged = true;
@@ -77,6 +77,6 @@ void ShuffleboardInstance::SelectTab(int index) {
   m_impl->rootMetaTable->GetEntry("Selected").ForceSetDouble(index);
 }
 
-void ShuffleboardInstance::SelectTab(wpi::StringRef title) {
+void ShuffleboardInstance::SelectTab(std::string_view title) {
   m_impl->rootMetaTable->GetEntry("Selected").ForceSetString(title);
 }
diff --git a/wpilibc/src/main/native/cpp/shuffleboard/ShuffleboardTab.cpp b/wpilibc/src/main/native/cpp/shuffleboard/ShuffleboardTab.cpp
index 1c91ca72e7..61e0e4541a 100644
--- a/wpilibc/src/main/native/cpp/shuffleboard/ShuffleboardTab.cpp
+++ b/wpilibc/src/main/native/cpp/shuffleboard/ShuffleboardTab.cpp
@@ -6,7 +6,7 @@
 
 using namespace frc;
 
-ShuffleboardTab::ShuffleboardTab(ShuffleboardRoot& root, wpi::StringRef title)
+ShuffleboardTab::ShuffleboardTab(ShuffleboardRoot& root, std::string_view title)
     : ShuffleboardValue(title), ShuffleboardContainer(title), m_root(root) {}
 
 ShuffleboardRoot& ShuffleboardTab::GetRoot() {
diff --git a/wpilibc/src/main/native/cpp/shuffleboard/WidgetType.cpp b/wpilibc/src/main/native/cpp/shuffleboard/WidgetType.cpp
index 79f7d1440d..3062cba9ad 100644
--- a/wpilibc/src/main/native/cpp/shuffleboard/WidgetType.cpp
+++ b/wpilibc/src/main/native/cpp/shuffleboard/WidgetType.cpp
@@ -6,6 +6,6 @@
 
 using namespace frc;
 
-wpi::StringRef WidgetType::GetWidgetName() const {
+std::string_view WidgetType::GetWidgetName() const {
   return m_widgetName;
 }
diff --git a/wpilibc/src/main/native/cpp/smartdashboard/FieldObject2d.cpp b/wpilibc/src/main/native/cpp/smartdashboard/FieldObject2d.cpp
index 2ea8237234..1483716da6 100644
--- a/wpilibc/src/main/native/cpp/smartdashboard/FieldObject2d.cpp
+++ b/wpilibc/src/main/native/cpp/smartdashboard/FieldObject2d.cpp
@@ -114,9 +114,9 @@ void FieldObject2d::UpdateEntry(bool setDefault) {
       p += 8;
     }
     if (setDefault) {
-      m_entry.SetDefaultRaw(wpi::StringRef{arr.data(), arr.size()});
+      m_entry.SetDefaultRaw({arr.data(), arr.size()});
     } else {
-      m_entry.ForceSetRaw(wpi::StringRef{arr.data(), arr.size()});
+      m_entry.ForceSetRaw({arr.data(), arr.size()});
     }
   }
 }
@@ -144,7 +144,7 @@ void FieldObject2d::UpdateFromEntry() const {
     }
   } else if (val->IsRaw()) {
     // treat it simply as an array of doubles
-    wpi::StringRef data = val->GetRaw();
+    std::string_view data = val->GetRaw();
 
     // must be triples of doubles
     auto size = data.size();
@@ -152,7 +152,7 @@ void FieldObject2d::UpdateFromEntry() const {
       return;
     }
     m_poses.resize(size / (3 * 8));
-    const char* p = data.begin();
+    const char* p = data.data();
     for (size_t i = 0; i < size / (3 * 8); ++i) {
       double x = wpi::BitsToDouble(
           wpi::support::endian::readNext<uint64_t, wpi::support::big,
diff --git a/wpilibc/src/main/native/cpp/smartdashboard/Mechanism2d.cpp b/wpilibc/src/main/native/cpp/smartdashboard/Mechanism2d.cpp
index 38f73f71dc..868ad48175 100644
--- a/wpilibc/src/main/native/cpp/smartdashboard/Mechanism2d.cpp
+++ b/wpilibc/src/main/native/cpp/smartdashboard/Mechanism2d.cpp
@@ -19,7 +19,8 @@ Mechanism2d::Mechanism2d(double width, double height,
   SetBackgroundColor(backgroundColor);
 }
 
-MechanismRoot2d* Mechanism2d::GetRoot(wpi::StringRef name, double x, double y) {
+MechanismRoot2d* Mechanism2d::GetRoot(std::string_view name, double x,
+                                      double y) {
   auto& obj = m_roots[name];
   if (obj) {
     return obj.get();
diff --git a/wpilibc/src/main/native/cpp/smartdashboard/SendableBuilderImpl.cpp b/wpilibc/src/main/native/cpp/smartdashboard/SendableBuilderImpl.cpp
index e41a6f0a96..7a3a5f009f 100644
--- a/wpilibc/src/main/native/cpp/smartdashboard/SendableBuilderImpl.cpp
+++ b/wpilibc/src/main/native/cpp/smartdashboard/SendableBuilderImpl.cpp
@@ -151,7 +151,7 @@ void SendableBuilderImpl::AddDoubleProperty(
 
 void SendableBuilderImpl::AddStringProperty(
     std::string_view key, std::function<std::string()> getter,
-    std::function<void(wpi::StringRef)> setter) {
+    std::function<void(std::string_view)> setter) {
   m_properties.emplace_back(*m_table, key);
   if (getter) {
     m_properties.back().update = [=](nt::NetworkTableEntry entry,
@@ -255,7 +255,7 @@ void SendableBuilderImpl::AddStringArrayProperty(
 
 void SendableBuilderImpl::AddRawProperty(
     std::string_view key, std::function<std::string()> getter,
-    std::function<void(wpi::StringRef)> setter) {
+    std::function<void(std::string_view)> setter) {
   m_properties.emplace_back(*m_table, key);
   if (getter) {
     m_properties.back().update = [=](nt::NetworkTableEntry entry,
@@ -303,8 +303,8 @@ void SendableBuilderImpl::AddValueProperty(
 
 void SendableBuilderImpl::AddSmallStringProperty(
     std::string_view key,
-    std::function<wpi::StringRef(wpi::SmallVectorImpl<char>& buf)> getter,
-    std::function<void(wpi::StringRef)> setter) {
+    std::function<std::string_view(wpi::SmallVectorImpl<char>& buf)> getter,
+    std::function<void(std::string_view)> setter) {
   m_properties.emplace_back(*m_table, key);
   if (getter) {
     m_properties.back().update = [=](nt::NetworkTableEntry entry,
@@ -418,8 +418,8 @@ void SendableBuilderImpl::AddSmallStringArrayProperty(
 
 void SendableBuilderImpl::AddSmallRawProperty(
     std::string_view key,
-    std::function<wpi::StringRef(wpi::SmallVectorImpl<char>& buf)> getter,
-    std::function<void(wpi::StringRef)> setter) {
+    std::function<std::string_view(wpi::SmallVectorImpl<char>& buf)> getter,
+    std::function<void(std::string_view)> setter) {
   m_properties.emplace_back(*m_table, key);
   if (getter) {
     m_properties.back().update = [=](nt::NetworkTableEntry entry,
diff --git a/wpilibc/src/main/native/cpp/smartdashboard/SmartDashboard.cpp b/wpilibc/src/main/native/cpp/smartdashboard/SmartDashboard.cpp
index 53ef7f382e..d7794707f2 100644
--- a/wpilibc/src/main/native/cpp/smartdashboard/SmartDashboard.cpp
+++ b/wpilibc/src/main/native/cpp/smartdashboard/SmartDashboard.cpp
@@ -44,7 +44,7 @@ void SmartDashboard::init() {
   Singleton::GetInstance();
 }
 
-bool SmartDashboard::ContainsKey(wpi::StringRef key) {
+bool SmartDashboard::ContainsKey(std::string_view key) {
   return Singleton::GetInstance().table->ContainsKey(key);
 }
 
@@ -52,39 +52,39 @@ std::vector<std::string> SmartDashboard::GetKeys(int types) {
   return Singleton::GetInstance().table->GetKeys(types);
 }
 
-void SmartDashboard::SetPersistent(wpi::StringRef key) {
+void SmartDashboard::SetPersistent(std::string_view key) {
   Singleton::GetInstance().table->GetEntry(key).SetPersistent();
 }
 
-void SmartDashboard::ClearPersistent(wpi::StringRef key) {
+void SmartDashboard::ClearPersistent(std::string_view key) {
   Singleton::GetInstance().table->GetEntry(key).ClearPersistent();
 }
 
-bool SmartDashboard::IsPersistent(wpi::StringRef key) {
+bool SmartDashboard::IsPersistent(std::string_view key) {
   return Singleton::GetInstance().table->GetEntry(key).IsPersistent();
 }
 
-void SmartDashboard::SetFlags(wpi::StringRef key, unsigned int flags) {
+void SmartDashboard::SetFlags(std::string_view key, unsigned int flags) {
   Singleton::GetInstance().table->GetEntry(key).SetFlags(flags);
 }
 
-void SmartDashboard::ClearFlags(wpi::StringRef key, unsigned int flags) {
+void SmartDashboard::ClearFlags(std::string_view key, unsigned int flags) {
   Singleton::GetInstance().table->GetEntry(key).ClearFlags(flags);
 }
 
-unsigned int SmartDashboard::GetFlags(wpi::StringRef key) {
+unsigned int SmartDashboard::GetFlags(std::string_view key) {
   return Singleton::GetInstance().table->GetEntry(key).GetFlags();
 }
 
-void SmartDashboard::Delete(wpi::StringRef key) {
+void SmartDashboard::Delete(std::string_view key) {
   Singleton::GetInstance().table->Delete(key);
 }
 
-nt::NetworkTableEntry SmartDashboard::GetEntry(wpi::StringRef key) {
+nt::NetworkTableEntry SmartDashboard::GetEntry(std::string_view key) {
   return Singleton::GetInstance().table->GetEntry(key);
 }
 
-void SmartDashboard::PutData(wpi::StringRef key, Sendable* data) {
+void SmartDashboard::PutData(std::string_view key, Sendable* data) {
   if (!data) {
     throw FRC_MakeError(err::NullParameter, "{}", "value");
   }
@@ -111,7 +111,7 @@ void SmartDashboard::PutData(Sendable* value) {
   }
 }
 
-Sendable* SmartDashboard::GetData(wpi::StringRef key) {
+Sendable* SmartDashboard::GetData(std::string_view key) {
   auto& inst = Singleton::GetInstance();
   std::scoped_lock lock(inst.tablesToDataMutex);
   auto it = inst.tablesToData.find(key);
@@ -121,128 +121,132 @@ Sendable* SmartDashboard::GetData(wpi::StringRef key) {
   return SendableRegistry::GetInstance().GetSendable(it->getValue());
 }
 
-bool SmartDashboard::PutBoolean(wpi::StringRef keyName, bool value) {
+bool SmartDashboard::PutBoolean(std::string_view keyName, bool value) {
   return Singleton::GetInstance().table->GetEntry(keyName).SetBoolean(value);
 }
 
-bool SmartDashboard::SetDefaultBoolean(wpi::StringRef key, bool defaultValue) {
+bool SmartDashboard::SetDefaultBoolean(std::string_view key,
+                                       bool defaultValue) {
   return Singleton::GetInstance().table->GetEntry(key).SetDefaultBoolean(
       defaultValue);
 }
 
-bool SmartDashboard::GetBoolean(wpi::StringRef keyName, bool defaultValue) {
+bool SmartDashboard::GetBoolean(std::string_view keyName, bool defaultValue) {
   return Singleton::GetInstance().table->GetEntry(keyName).GetBoolean(
       defaultValue);
 }
 
-bool SmartDashboard::PutNumber(wpi::StringRef keyName, double value) {
+bool SmartDashboard::PutNumber(std::string_view keyName, double value) {
   return Singleton::GetInstance().table->GetEntry(keyName).SetDouble(value);
 }
 
-bool SmartDashboard::SetDefaultNumber(wpi::StringRef key, double defaultValue) {
+bool SmartDashboard::SetDefaultNumber(std::string_view key,
+                                      double defaultValue) {
   return Singleton::GetInstance().table->GetEntry(key).SetDefaultDouble(
       defaultValue);
 }
 
-double SmartDashboard::GetNumber(wpi::StringRef keyName, double defaultValue) {
+double SmartDashboard::GetNumber(std::string_view keyName,
+                                 double defaultValue) {
   return Singleton::GetInstance().table->GetEntry(keyName).GetDouble(
       defaultValue);
 }
 
-bool SmartDashboard::PutString(wpi::StringRef keyName, wpi::StringRef value) {
+bool SmartDashboard::PutString(std::string_view keyName,
+                               std::string_view value) {
   return Singleton::GetInstance().table->GetEntry(keyName).SetString(value);
 }
 
-bool SmartDashboard::SetDefaultString(wpi::StringRef key,
-                                      wpi::StringRef defaultValue) {
+bool SmartDashboard::SetDefaultString(std::string_view key,
+                                      std::string_view defaultValue) {
   return Singleton::GetInstance().table->GetEntry(key).SetDefaultString(
       defaultValue);
 }
 
-std::string SmartDashboard::GetString(wpi::StringRef keyName,
-                                      wpi::StringRef defaultValue) {
+std::string SmartDashboard::GetString(std::string_view keyName,
+                                      std::string_view defaultValue) {
   return Singleton::GetInstance().table->GetEntry(keyName).GetString(
       defaultValue);
 }
 
-bool SmartDashboard::PutBooleanArray(wpi::StringRef key,
+bool SmartDashboard::PutBooleanArray(std::string_view key,
                                      wpi::ArrayRef<int> value) {
   return Singleton::GetInstance().table->GetEntry(key).SetBooleanArray(value);
 }
 
-bool SmartDashboard::SetDefaultBooleanArray(wpi::StringRef key,
+bool SmartDashboard::SetDefaultBooleanArray(std::string_view key,
                                             wpi::ArrayRef<int> defaultValue) {
   return Singleton::GetInstance().table->GetEntry(key).SetDefaultBooleanArray(
       defaultValue);
 }
 
 std::vector<int> SmartDashboard::GetBooleanArray(
-    wpi::StringRef key, wpi::ArrayRef<int> defaultValue) {
+    std::string_view key, wpi::ArrayRef<int> defaultValue) {
   return Singleton::GetInstance().table->GetEntry(key).GetBooleanArray(
       defaultValue);
 }
 
-bool SmartDashboard::PutNumberArray(wpi::StringRef key,
+bool SmartDashboard::PutNumberArray(std::string_view key,
                                     wpi::ArrayRef<double> value) {
   return Singleton::GetInstance().table->GetEntry(key).SetDoubleArray(value);
 }
 
-bool SmartDashboard::SetDefaultNumberArray(wpi::StringRef key,
+bool SmartDashboard::SetDefaultNumberArray(std::string_view key,
                                            wpi::ArrayRef<double> defaultValue) {
   return Singleton::GetInstance().table->GetEntry(key).SetDefaultDoubleArray(
       defaultValue);
 }
 
 std::vector<double> SmartDashboard::GetNumberArray(
-    wpi::StringRef key, wpi::ArrayRef<double> defaultValue) {
+    std::string_view key, wpi::ArrayRef<double> defaultValue) {
   return Singleton::GetInstance().table->GetEntry(key).GetDoubleArray(
       defaultValue);
 }
 
-bool SmartDashboard::PutStringArray(wpi::StringRef key,
+bool SmartDashboard::PutStringArray(std::string_view key,
                                     wpi::ArrayRef<std::string> value) {
   return Singleton::GetInstance().table->GetEntry(key).SetStringArray(value);
 }
 
 bool SmartDashboard::SetDefaultStringArray(
-    wpi::StringRef key, wpi::ArrayRef<std::string> defaultValue) {
+    std::string_view key, wpi::ArrayRef<std::string> defaultValue) {
   return Singleton::GetInstance().table->GetEntry(key).SetDefaultStringArray(
       defaultValue);
 }
 
 std::vector<std::string> SmartDashboard::GetStringArray(
-    wpi::StringRef key, wpi::ArrayRef<std::string> defaultValue) {
+    std::string_view key, wpi::ArrayRef<std::string> defaultValue) {
   return Singleton::GetInstance().table->GetEntry(key).GetStringArray(
       defaultValue);
 }
 
-bool SmartDashboard::PutRaw(wpi::StringRef key, wpi::StringRef value) {
+bool SmartDashboard::PutRaw(std::string_view key, std::string_view value) {
   return Singleton::GetInstance().table->GetEntry(key).SetRaw(value);
 }
 
-bool SmartDashboard::SetDefaultRaw(wpi::StringRef key,
-                                   wpi::StringRef defaultValue) {
+bool SmartDashboard::SetDefaultRaw(std::string_view key,
+                                   std::string_view defaultValue) {
   return Singleton::GetInstance().table->GetEntry(key).SetDefaultRaw(
       defaultValue);
 }
 
-std::string SmartDashboard::GetRaw(wpi::StringRef key,
-                                   wpi::StringRef defaultValue) {
+std::string SmartDashboard::GetRaw(std::string_view key,
+                                   std::string_view defaultValue) {
   return Singleton::GetInstance().table->GetEntry(key).GetRaw(defaultValue);
 }
 
-bool SmartDashboard::PutValue(wpi::StringRef keyName,
+bool SmartDashboard::PutValue(std::string_view keyName,
                               std::shared_ptr<nt::Value> value) {
   return Singleton::GetInstance().table->GetEntry(keyName).SetValue(value);
 }
 
-bool SmartDashboard::SetDefaultValue(wpi::StringRef key,
+bool SmartDashboard::SetDefaultValue(std::string_view key,
                                      std::shared_ptr<nt::Value> defaultValue) {
   return Singleton::GetInstance().table->GetEntry(key).SetDefaultValue(
       defaultValue);
 }
 
-std::shared_ptr<nt::Value> SmartDashboard::GetValue(wpi::StringRef keyName) {
+std::shared_ptr<nt::Value> SmartDashboard::GetValue(std::string_view keyName) {
   return Singleton::GetInstance().table->GetEntry(keyName).GetValue();
 }
 
diff --git a/wpilibc/src/main/native/cppcs/RobotBase.cpp b/wpilibc/src/main/native/cppcs/RobotBase.cpp
index f0fab4ddce..ab8bf896e1 100644
--- a/wpilibc/src/main/native/cppcs/RobotBase.cpp
+++ b/wpilibc/src/main/native/cppcs/RobotBase.cpp
@@ -30,12 +30,12 @@ using namespace frc;
 
 int frc::RunHALInitialization() {
   if (!HAL_Initialize(500, 0)) {
-    wpi::errs() << "FATAL ERROR: HAL could not be initialized\n";
+    std::puts("FATAL ERROR: HAL could not be initialized");
     return -1;
   }
   HAL_Report(HALUsageReporting::kResourceType_Language,
              HALUsageReporting::kLanguage_CPlusPlus, 0, GetWPILibVersion());
-  wpi::outs() << "\n********** Robot program starting **********\n";
+  std::puts("\n********** Robot program starting **********");
   return 0;
 }
 
@@ -124,8 +124,8 @@ static void SetupCameraServerShared() {
 #endif
 
   if (!cameraServerLib) {
-    wpi::outs() << "Camera Server Library Not Found\n";
-    wpi::outs().flush();
+    std::puts("Camera Server Library Not Found");
+    std::fflush(stdout);
     return;
   }
   auto symbol = dlsym(cameraServerLib, "CameraServer_SetCameraServerShared");
@@ -133,15 +133,15 @@ static void SetupCameraServerShared() {
     auto setCameraServerShared = (SetCameraServerSharedFP)symbol;
     setCameraServerShared(new WPILibCameraServerShared{});
   } else {
-    wpi::outs() << "Camera Server Shared Symbol Missing\n";
-    wpi::outs().flush();
+    std::puts("Camera Server Shared Symbol Missing");
+    std::fflush(stdout);
   }
 #else
   CameraServer_SetCameraServerShared(new WPILibCameraServerShared{});
 #endif
 #else
-  wpi::outs() << "Not loading CameraServerShared\n";
-  wpi::outs().flush();
+  std::puts("Not loading CameraServerShared");
+  std::fflush(stdout);
 #endif
 }
 
diff --git a/wpilibc/src/main/native/include/frc/Preferences.h b/wpilibc/src/main/native/include/frc/Preferences.h
index 3a6d597646..0df03bce77 100644
--- a/wpilibc/src/main/native/include/frc/Preferences.h
+++ b/wpilibc/src/main/native/include/frc/Preferences.h
@@ -8,6 +8,7 @@
 
 #include <memory>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <networktables/NetworkTable.h>
@@ -53,7 +54,8 @@ class Preferences {
    * @param defaultValue the value to return if none exists in the table
    * @return either the value in the table, or the defaultValue
    */
-  std::string GetString(wpi::StringRef key, wpi::StringRef defaultValue = "");
+  std::string GetString(std::string_view key,
+                        std::string_view defaultValue = "");
 
   /**
    * Returns the int at the given key.  If this table does not have a value for
@@ -63,7 +65,7 @@ class Preferences {
    * @param defaultValue the value to return if none exists in the table
    * @return either the value in the table, or the defaultValue
    */
-  int GetInt(wpi::StringRef key, int defaultValue = 0);
+  int GetInt(std::string_view key, int defaultValue = 0);
 
   /**
    * Returns the double at the given key.  If this table does not have a value
@@ -73,7 +75,7 @@ class Preferences {
    * @param defaultValue the value to return if none exists in the table
    * @return either the value in the table, or the defaultValue
    */
-  double GetDouble(wpi::StringRef key, double defaultValue = 0.0);
+  double GetDouble(std::string_view key, double defaultValue = 0.0);
 
   /**
    * Returns the float at the given key.  If this table does not have a value
@@ -83,7 +85,7 @@ class Preferences {
    * @param defaultValue the value to return if none exists in the table
    * @return either the value in the table, or the defaultValue
    */
-  float GetFloat(wpi::StringRef key, float defaultValue = 0.0);
+  float GetFloat(std::string_view key, float defaultValue = 0.0);
 
   /**
    * Returns the boolean at the given key.  If this table does not have a value
@@ -93,7 +95,7 @@ class Preferences {
    * @param defaultValue the value to return if none exists in the table
    * @return either the value in the table, or the defaultValue
    */
-  bool GetBoolean(wpi::StringRef key, bool defaultValue = false);
+  bool GetBoolean(std::string_view key, bool defaultValue = false);
 
   /**
    * Returns the long (int64_t) at the given key.  If this table does not have a
@@ -104,7 +106,7 @@ class Preferences {
    * @param defaultValue the value to return if none exists in the table
    * @return either the value in the table, or the defaultValue
    */
-  int64_t GetLong(wpi::StringRef key, int64_t defaultValue = 0);
+  int64_t GetLong(std::string_view key, int64_t defaultValue = 0);
 
   /**
    * Puts the given string into the preferences table.
@@ -115,7 +117,7 @@ class Preferences {
    * @param key   the key
    * @param value the value
    */
-  void SetString(wpi::StringRef key, wpi::StringRef value);
+  void SetString(std::string_view key, std::string_view value);
 
   /**
    * Puts the given string into the preferences table.
@@ -127,13 +129,13 @@ class Preferences {
    * @param value the value
    */
   WPI_DEPRECATED("Use SetString instead.")
-  void PutString(wpi::StringRef key, wpi::StringRef value);
+  void PutString(std::string_view key, std::string_view value);
 
   /**
    * Puts the given string into the preferences table if it doesn't
    * already exist.
    */
-  void InitString(wpi::StringRef key, wpi::StringRef value);
+  void InitString(std::string_view key, std::string_view value);
 
   /**
    * Puts the given int into the preferences table.
@@ -143,7 +145,7 @@ class Preferences {
    * @param key   the key
    * @param value the value
    */
-  void SetInt(wpi::StringRef key, int value);
+  void SetInt(std::string_view key, int value);
 
   /**
    * Puts the given int into the preferences table.
@@ -154,13 +156,13 @@ class Preferences {
    * @param value the value
    */
   WPI_DEPRECATED("Use SetInt instead.")
-  void PutInt(wpi::StringRef key, int value);
+  void PutInt(std::string_view key, int value);
 
   /**
    * Puts the given int into the preferences table if it doesn't
    * already exist.
    */
-  void InitInt(wpi::StringRef key, int value);
+  void InitInt(std::string_view key, int value);
 
   /**
    * Puts the given double into the preferences table.
@@ -170,7 +172,7 @@ class Preferences {
    * @param key   the key
    * @param value the value
    */
-  void SetDouble(wpi::StringRef key, double value);
+  void SetDouble(std::string_view key, double value);
 
   /**
    * Puts the given double into the preferences table.
@@ -181,13 +183,13 @@ class Preferences {
    * @param value the value
    */
   WPI_DEPRECATED("Use SetDouble instead.")
-  void PutDouble(wpi::StringRef key, double value);
+  void PutDouble(std::string_view key, double value);
 
   /**
    * Puts the given double into the preferences table if it doesn't
    * already exist.
    */
-  void InitDouble(wpi::StringRef key, double value);
+  void InitDouble(std::string_view key, double value);
 
   /**
    * Puts the given float into the preferences table.
@@ -197,7 +199,7 @@ class Preferences {
    * @param key   the key
    * @param value the value
    */
-  void SetFloat(wpi::StringRef key, float value);
+  void SetFloat(std::string_view key, float value);
 
   /**
    * Puts the given float into the preferences table.
@@ -208,13 +210,13 @@ class Preferences {
    * @param value the value
    */
   WPI_DEPRECATED("Use SetFloat instead.")
-  void PutFloat(wpi::StringRef key, float value);
+  void PutFloat(std::string_view key, float value);
 
   /**
    * Puts the given float into the preferences table if it doesn't
    * already exist.
    */
-  void InitFloat(wpi::StringRef key, float value);
+  void InitFloat(std::string_view key, float value);
 
   /**
    * Puts the given boolean into the preferences table.
@@ -224,7 +226,7 @@ class Preferences {
    * @param key   the key
    * @param value the value
    */
-  void SetBoolean(wpi::StringRef key, bool value);
+  void SetBoolean(std::string_view key, bool value);
 
   /**
    * Puts the given boolean into the preferences table.
@@ -235,13 +237,13 @@ class Preferences {
    * @param value the value
    */
   WPI_DEPRECATED("Use SetBoolean instead.")
-  void PutBoolean(wpi::StringRef key, bool value);
+  void PutBoolean(std::string_view key, bool value);
 
   /**
    * Puts the given boolean into the preferences table if it doesn't
    * already exist.
    */
-  void InitBoolean(wpi::StringRef key, bool value);
+  void InitBoolean(std::string_view key, bool value);
 
   /**
    * Puts the given long (int64_t) into the preferences table.
@@ -251,7 +253,7 @@ class Preferences {
    * @param key   the key
    * @param value the value
    */
-  void SetLong(wpi::StringRef key, int64_t value);
+  void SetLong(std::string_view key, int64_t value);
 
   /**
    * Puts the given long (int64_t) into the preferences table.
@@ -262,13 +264,13 @@ class Preferences {
    * @param value the value
    */
   WPI_DEPRECATED("Use SetLong instead.")
-  void PutLong(wpi::StringRef key, int64_t value);
+  void PutLong(std::string_view key, int64_t value);
 
   /**
    * Puts the given long into the preferences table if it doesn't
    * already exist.
    */
-  void InitLong(wpi::StringRef key, int64_t value);
+  void InitLong(std::string_view key, int64_t value);
 
   /**
    * Returns whether or not there is a key with the given name.
@@ -276,14 +278,14 @@ class Preferences {
    * @param key the key
    * @return if there is a value at the given key
    */
-  bool ContainsKey(wpi::StringRef key);
+  bool ContainsKey(std::string_view key);
 
   /**
    * Remove a preference.
    *
    * @param key the key
    */
-  void Remove(wpi::StringRef key);
+  void Remove(std::string_view key);
 
   /**
    * Remove all preferences.
diff --git a/wpilibc/src/main/native/include/frc/RobotBase.h b/wpilibc/src/main/native/include/frc/RobotBase.h
index e0c1592fef..6e5d3b5137 100644
--- a/wpilibc/src/main/native/include/frc/RobotBase.h
+++ b/wpilibc/src/main/native/include/frc/RobotBase.h
@@ -11,7 +11,6 @@
 #include <hal/Main.h>
 #include <wpi/condition_variable.h>
 #include <wpi/mutex.h>
-#include <wpi/raw_ostream.h>
 
 #include "frc/Errors.h"
 
diff --git a/wpilibc/src/main/native/include/frc/SerialPort.h b/wpilibc/src/main/native/include/frc/SerialPort.h
index f26d53cc3b..7fff14acaf 100644
--- a/wpilibc/src/main/native/include/frc/SerialPort.h
+++ b/wpilibc/src/main/native/include/frc/SerialPort.h
@@ -144,7 +144,7 @@ class SerialPort {
    * Use Write({data, len}) to get a buffer that is shorter than the length of
    * the string.
    *
-   * @param buffer StringRef to the buffer to read the bytes from.
+   * @param buffer the buffer to read the bytes from.
    * @return The number of bytes actually written into the port.
    */
   int Write(std::string_view buffer);
diff --git a/wpilibc/src/main/native/include/frc/Tracer.h b/wpilibc/src/main/native/include/frc/Tracer.h
index 7c36f58fdd..2acb017cb3 100644
--- a/wpilibc/src/main/native/include/frc/Tracer.h
+++ b/wpilibc/src/main/native/include/frc/Tracer.h
@@ -5,10 +5,10 @@
 #pragma once
 
 #include <chrono>
+#include <string_view>
 
 #include <hal/cpp/fpga_clock.h>
 #include <wpi/StringMap.h>
-#include <wpi/StringRef.h>
 
 namespace wpi {
 class raw_ostream;
@@ -48,7 +48,7 @@ class Tracer {
    *
    * @param epochName The name to associate with the epoch.
    */
-  void AddEpoch(wpi::StringRef epochName);
+  void AddEpoch(std::string_view epochName);
 
   /**
    * Prints list of epochs added so far and their times to the DriverStation.
diff --git a/wpilibc/src/main/native/include/frc/Watchdog.h b/wpilibc/src/main/native/include/frc/Watchdog.h
index 9bb15630aa..d85674d8c6 100644
--- a/wpilibc/src/main/native/include/frc/Watchdog.h
+++ b/wpilibc/src/main/native/include/frc/Watchdog.h
@@ -5,10 +5,10 @@
 #pragma once
 
 #include <functional>
+#include <string_view>
 #include <utility>
 
 #include <units/time.h>
-#include <wpi/StringRef.h>
 
 #include "frc/Tracer.h"
 
@@ -76,7 +76,7 @@ class Watchdog {
    *
    * @param epochName The name to associate with the epoch.
    */
-  void AddEpoch(wpi::StringRef epochName);
+  void AddEpoch(std::string_view epochName);
 
   /**
    * Prints list of epochs added so far and their times.
diff --git a/wpilibc/src/main/native/include/frc/shuffleboard/LayoutType.h b/wpilibc/src/main/native/include/frc/shuffleboard/LayoutType.h
index 413af06034..5fa5ca4ad0 100644
--- a/wpilibc/src/main/native/include/frc/shuffleboard/LayoutType.h
+++ b/wpilibc/src/main/native/include/frc/shuffleboard/LayoutType.h
@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include <wpi/StringRef.h>
+#include <string_view>
 
 namespace frc {
 
@@ -25,7 +25,7 @@ class LayoutType {
    * Gets the string type of the layout as defined by that layout in
    * Shuffleboard.
    */
-  wpi::StringRef GetLayoutName() const;
+  std::string_view GetLayoutName() const;
 
  private:
   const char* m_layoutName;
diff --git a/wpilibc/src/main/native/include/frc/shuffleboard/RecordingController.h b/wpilibc/src/main/native/include/frc/shuffleboard/RecordingController.h
index 716597c7bb..83b23a424b 100644
--- a/wpilibc/src/main/native/include/frc/shuffleboard/RecordingController.h
+++ b/wpilibc/src/main/native/include/frc/shuffleboard/RecordingController.h
@@ -6,11 +6,11 @@
 
 #include <memory>
 #include <string>
+#include <string_view>
 
 #include <networktables/NetworkTable.h>
 #include <networktables/NetworkTableInstance.h>
 #include <wpi/SmallVector.h>
-#include <wpi/StringRef.h>
 
 #include "frc/shuffleboard/ShuffleboardEventImportance.h"
 
@@ -23,10 +23,10 @@ class RecordingController final {
 
   void StartRecording();
   void StopRecording();
-  void SetRecordingFileNameFormat(wpi::StringRef format);
+  void SetRecordingFileNameFormat(std::string_view format);
   void ClearRecordingFileNameFormat();
 
-  void AddEventMarker(wpi::StringRef name, wpi::StringRef description,
+  void AddEventMarker(std::string_view name, std::string_view description,
                       ShuffleboardEventImportance importance);
 
  private:
diff --git a/wpilibc/src/main/native/include/frc/shuffleboard/Shuffleboard.h b/wpilibc/src/main/native/include/frc/shuffleboard/Shuffleboard.h
index 6952295a0d..9b691fd7ea 100644
--- a/wpilibc/src/main/native/include/frc/shuffleboard/Shuffleboard.h
+++ b/wpilibc/src/main/native/include/frc/shuffleboard/Shuffleboard.h
@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include <wpi/StringRef.h>
+#include <string_view>
 
 #include "frc/shuffleboard/RecordingController.h"
 #include "frc/shuffleboard/ShuffleboardEventImportance.h"
@@ -77,7 +77,7 @@ class Shuffleboard final {
    * @param title the title of the tab
    * @return the tab with the given title
    */
-  static ShuffleboardTab& GetTab(wpi::StringRef title);
+  static ShuffleboardTab& GetTab(std::string_view title);
 
   /**
    * Selects the tab in the dashboard with the given index in the range
@@ -93,7 +93,7 @@ class Shuffleboard final {
    *
    * @param title the title of the tab to select
    */
-  static void SelectTab(wpi::StringRef title);
+  static void SelectTab(std::string_view title);
 
   /**
    * Enables user control of widgets containing actuators: speed controllers,
@@ -141,7 +141,7 @@ class Shuffleboard final {
    *
    * @param format the format for the
    */
-  static void SetRecordingFileNameFormat(wpi::StringRef format);
+  static void SetRecordingFileNameFormat(std::string_view format);
 
   /**
    * Clears the custom name format for recording files. New recordings will use
@@ -163,7 +163,8 @@ class Shuffleboard final {
    * @param description a description of the event
    * @param importance  the importance of the event
    */
-  static void AddEventMarker(wpi::StringRef name, wpi::StringRef description,
+  static void AddEventMarker(std::string_view name,
+                             std::string_view description,
                              ShuffleboardEventImportance importance);
 
   /**
@@ -177,7 +178,7 @@ class Shuffleboard final {
    * @param name        the name of the event
    * @param importance  the importance of the event
    */
-  static void AddEventMarker(wpi::StringRef name,
+  static void AddEventMarker(std::string_view name,
                              ShuffleboardEventImportance importance);
 
  private:
diff --git a/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardEventImportance.h b/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardEventImportance.h
index f989fb3915..1fa9c91f3d 100644
--- a/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardEventImportance.h
+++ b/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardEventImportance.h
@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include <wpi/StringRef.h>
+#include <string_view>
 
 namespace frc {
 
@@ -14,7 +14,7 @@ namespace frc {
 
 enum ShuffleboardEventImportance { kTrivial, kLow, kNormal, kHigh, kCritical };
 
-inline wpi::StringRef ShuffleboardEventImportanceName(
+inline std::string_view ShuffleboardEventImportanceName(
     ShuffleboardEventImportance importance) {
   switch (importance) {
     case kTrivial:
diff --git a/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardInstance.h b/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardInstance.h
index 20ddc6bfb3..2885af7b8a 100644
--- a/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardInstance.h
+++ b/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardInstance.h
@@ -5,6 +5,7 @@
 #pragma once
 
 #include <memory>
+#include <string_view>
 
 #include "frc/shuffleboard/ShuffleboardRoot.h"
 #include "frc/shuffleboard/ShuffleboardTab.h"
@@ -19,7 +20,7 @@ class ShuffleboardInstance final : public ShuffleboardRoot {
   ShuffleboardInstance(ShuffleboardInstance&&) = default;
   ShuffleboardInstance& operator=(ShuffleboardInstance&&) = default;
 
-  frc::ShuffleboardTab& GetTab(wpi::StringRef title) override;
+  frc::ShuffleboardTab& GetTab(std::string_view title) override;
 
   void Update() override;
 
@@ -29,7 +30,7 @@ class ShuffleboardInstance final : public ShuffleboardRoot {
 
   void SelectTab(int index) override;
 
-  void SelectTab(wpi::StringRef) override;
+  void SelectTab(std::string_view) override;
 
  private:
   struct Impl;
diff --git a/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardRoot.h b/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardRoot.h
index f8d98f753f..1e766a84e4 100644
--- a/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardRoot.h
+++ b/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardRoot.h
@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include <wpi/StringRef.h>
+#include <string_view>
 
 namespace frc {
 
@@ -25,7 +25,7 @@ class ShuffleboardRoot {
    * @param title the title of the tab
    * @return the tab with the given title
    */
-  virtual ShuffleboardTab& GetTab(wpi::StringRef title) = 0;
+  virtual ShuffleboardTab& GetTab(std::string_view title) = 0;
 
   /**
    * Updates all tabs.
@@ -57,7 +57,7 @@ class ShuffleboardRoot {
    *
    * @param title the title of the tab to select
    */
-  virtual void SelectTab(wpi::StringRef title) = 0;
+  virtual void SelectTab(std::string_view title) = 0;
 };
 
 }  // namespace frc
diff --git a/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardTab.h b/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardTab.h
index a23890bdd7..1dd1aac311 100644
--- a/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardTab.h
+++ b/wpilibc/src/main/native/include/frc/shuffleboard/ShuffleboardTab.h
@@ -5,9 +5,9 @@
 #pragma once
 
 #include <memory>
+#include <string_view>
 
 #include <networktables/NetworkTable.h>
-#include <wpi/StringRef.h>
 
 #include "frc/shuffleboard/ShuffleboardContainer.h"
 
@@ -24,7 +24,7 @@ class ShuffleboardRoot;
  */
 class ShuffleboardTab final : public ShuffleboardContainer {
  public:
-  ShuffleboardTab(ShuffleboardRoot& root, wpi::StringRef title);
+  ShuffleboardTab(ShuffleboardRoot& root, std::string_view title);
 
   ShuffleboardRoot& GetRoot();
 
diff --git a/wpilibc/src/main/native/include/frc/shuffleboard/WidgetType.h b/wpilibc/src/main/native/include/frc/shuffleboard/WidgetType.h
index 6dd30b5f02..13805bb85e 100644
--- a/wpilibc/src/main/native/include/frc/shuffleboard/WidgetType.h
+++ b/wpilibc/src/main/native/include/frc/shuffleboard/WidgetType.h
@@ -4,7 +4,7 @@
 
 #pragma once
 
-#include <wpi/StringRef.h>
+#include <string_view>
 
 namespace frc {
 
@@ -25,7 +25,7 @@ class WidgetType {
    * Gets the string type of the widget as defined by that widget in
    * Shuffleboard.
    */
-  wpi::StringRef GetWidgetName() const;
+  std::string_view GetWidgetName() const;
 
  private:
   const char* m_widgetName;
diff --git a/wpilibc/src/main/native/include/frc/simulation/CallbackStore.h b/wpilibc/src/main/native/include/frc/simulation/CallbackStore.h
index 0a13a4ff10..61cc6b291b 100644
--- a/wpilibc/src/main/native/include/frc/simulation/CallbackStore.h
+++ b/wpilibc/src/main/native/include/frc/simulation/CallbackStore.h
@@ -5,15 +5,15 @@
 #pragma once
 
 #include <functional>
+#include <string_view>
 
 #include <hal/Value.h>
-#include <wpi/StringRef.h>
 
 namespace frc::sim {
 
-using NotifyCallback = std::function<void(wpi::StringRef, const HAL_Value*)>;
+using NotifyCallback = std::function<void(std::string_view, const HAL_Value*)>;
 using ConstBufferCallback = std::function<void(
-    wpi::StringRef, const unsigned char* buffer, unsigned int count)>;
+    std::string_view, const unsigned char* buffer, unsigned int count)>;
 using CancelCallbackFunc = void (*)(int32_t index, int32_t uid);
 using CancelCallbackNoIndexFunc = void (*)(int32_t uid);
 using CancelCallbackChannelFunc = void (*)(int32_t index, int32_t channel,
diff --git a/wpilibc/src/main/native/include/frc/smartdashboard/Mechanism2d.h b/wpilibc/src/main/native/include/frc/smartdashboard/Mechanism2d.h
index 9311b54641..7ddc976c36 100644
--- a/wpilibc/src/main/native/include/frc/smartdashboard/Mechanism2d.h
+++ b/wpilibc/src/main/native/include/frc/smartdashboard/Mechanism2d.h
@@ -59,7 +59,7 @@ class Mechanism2d : public Sendable, public SendableHelper<Mechanism2d> {
    * @param y the root y coordinate
    * @return a new root object, or the existing one with the given name.
    */
-  MechanismRoot2d* GetRoot(wpi::StringRef name, double x, double y);
+  MechanismRoot2d* GetRoot(std::string_view name, double x, double y);
 
   /**
    * Set the Mechanism2d background color.
diff --git a/wpilibc/src/main/native/include/frc/smartdashboard/MechanismObject2d.h b/wpilibc/src/main/native/include/frc/smartdashboard/MechanismObject2d.h
index 3821f617c2..c4185e7f88 100644
--- a/wpilibc/src/main/native/include/frc/smartdashboard/MechanismObject2d.h
+++ b/wpilibc/src/main/native/include/frc/smartdashboard/MechanismObject2d.h
@@ -14,6 +14,8 @@
 #include <networktables/NetworkTable.h>
 #include <wpi/StringMap.h>
 
+#include "frc/Errors.h"
+
 namespace frc {
 
 /**
@@ -63,13 +65,14 @@ class MechanismObject2d {
   template <typename T, typename... Args,
             typename =
                 std::enable_if_t<std::is_convertible_v<T*, MechanismObject2d*>>>
-  T* Append(wpi::StringRef name, Args&&... args) {
+  T* Append(std::string_view name, Args&&... args) {
     std::scoped_lock lock(m_mutex);
     auto& obj = m_objects[name];
     if (obj) {
-      throw std::runtime_error(("MechanismObject names must be unique! `" +
-                                name + "` was inserted twice!")
-                                   .str());
+      throw FRC_MakeError(
+          err::Error,
+          "MechanismObject names must be unique! `{}` was inserted twice!",
+          name);
     }
     obj = std::make_unique<T>(name, std::forward<Args>(args)...);
     T* ex = static_cast<T*>(obj.get());
diff --git a/wpilibc/src/main/native/include/frc/smartdashboard/SendableBuilder.h b/wpilibc/src/main/native/include/frc/smartdashboard/SendableBuilder.h
index 432854f1b4..3ec3831cef 100644
--- a/wpilibc/src/main/native/include/frc/smartdashboard/SendableBuilder.h
+++ b/wpilibc/src/main/native/include/frc/smartdashboard/SendableBuilder.h
@@ -96,7 +96,7 @@ class SendableBuilder {
    */
   virtual void AddStringProperty(
       std::string_view key, std::function<std::string()> getter,
-      std::function<void(wpi::StringRef)> setter) = 0;
+      std::function<void(std::string_view)> setter) = 0;
 
   /**
    * Add a boolean array property.
@@ -140,7 +140,7 @@ class SendableBuilder {
    */
   virtual void AddRawProperty(std::string_view key,
                               std::function<std::string()> getter,
-                              std::function<void(wpi::StringRef)> setter) = 0;
+                              std::function<void(std::string_view)> setter) = 0;
 
   /**
    * Add a NetworkTableValue property.
@@ -162,8 +162,8 @@ class SendableBuilder {
    */
   virtual void AddSmallStringProperty(
       std::string_view key,
-      std::function<wpi::StringRef(wpi::SmallVectorImpl<char>& buf)> getter,
-      std::function<void(wpi::StringRef)> setter) = 0;
+      std::function<std::string_view(wpi::SmallVectorImpl<char>& buf)> getter,
+      std::function<void(std::string_view)> setter) = 0;
 
   /**
    * Add a boolean array property (SmallVector form).
@@ -213,8 +213,8 @@ class SendableBuilder {
    */
   virtual void AddSmallRawProperty(
       std::string_view key,
-      std::function<wpi::StringRef(wpi::SmallVectorImpl<char>& buf)> getter,
-      std::function<void(wpi::StringRef)> setter) = 0;
+      std::function<std::string_view(wpi::SmallVectorImpl<char>& buf)> getter,
+      std::function<void(std::string_view)> setter) = 0;
 
   /**
    * Get the network table.
diff --git a/wpilibc/src/main/native/include/frc/smartdashboard/SendableBuilderImpl.h b/wpilibc/src/main/native/include/frc/smartdashboard/SendableBuilderImpl.h
index 34eeb668ab..34b9d59673 100644
--- a/wpilibc/src/main/native/include/frc/smartdashboard/SendableBuilderImpl.h
+++ b/wpilibc/src/main/native/include/frc/smartdashboard/SendableBuilderImpl.h
@@ -100,7 +100,7 @@ class SendableBuilderImpl : public SendableBuilder {
 
   void AddStringProperty(std::string_view key,
                          std::function<std::string()> getter,
-                         std::function<void(wpi::StringRef)> setter) override;
+                         std::function<void(std::string_view)> setter) override;
 
   void AddBooleanArrayProperty(
       std::string_view key, std::function<std::vector<int>()> getter,
@@ -115,7 +115,7 @@ class SendableBuilderImpl : public SendableBuilder {
       std::function<void(wpi::ArrayRef<std::string>)> setter) override;
 
   void AddRawProperty(std::string_view key, std::function<std::string()> getter,
-                      std::function<void(wpi::StringRef)> setter) override;
+                      std::function<void(std::string_view)> setter) override;
 
   void AddValueProperty(
       std::string_view key, std::function<std::shared_ptr<nt::Value>()> getter,
@@ -123,8 +123,8 @@ class SendableBuilderImpl : public SendableBuilder {
 
   void AddSmallStringProperty(
       std::string_view key,
-      std::function<wpi::StringRef(wpi::SmallVectorImpl<char>& buf)> getter,
-      std::function<void(wpi::StringRef)> setter) override;
+      std::function<std::string_view(wpi::SmallVectorImpl<char>& buf)> getter,
+      std::function<void(std::string_view)> setter) override;
 
   void AddSmallBooleanArrayProperty(
       std::string_view key,
@@ -146,8 +146,8 @@ class SendableBuilderImpl : public SendableBuilder {
 
   void AddSmallRawProperty(
       std::string_view key,
-      std::function<wpi::StringRef(wpi::SmallVectorImpl<char>& buf)> getter,
-      std::function<void(wpi::StringRef)> setter) override;
+      std::function<std::string_view(wpi::SmallVectorImpl<char>& buf)> getter,
+      std::function<void(std::string_view)> setter) override;
 
  private:
   struct Property {
diff --git a/wpilibc/src/main/native/include/frc/smartdashboard/SendableChooser.h b/wpilibc/src/main/native/include/frc/smartdashboard/SendableChooser.h
index 4f55576c91..26a1671ab6 100644
--- a/wpilibc/src/main/native/include/frc/smartdashboard/SendableChooser.h
+++ b/wpilibc/src/main/native/include/frc/smartdashboard/SendableChooser.h
@@ -5,9 +5,9 @@
 #pragma once
 
 #include <memory>
+#include <string_view>
 
 #include <wpi/StringMap.h>
-#include <wpi/StringRef.h>
 #include <wpi/deprecated.h>
 
 #include "frc/smartdashboard/SendableBuilder.h"
@@ -56,7 +56,7 @@ class SendableChooser : public SendableChooserBase {
    * @param name   the name of the option
    * @param object the option
    */
-  void AddOption(wpi::StringRef name, T object);
+  void AddOption(std::string_view name, T object);
 
   /**
    * Add the given object to the list of options and marks it as the default.
@@ -67,7 +67,7 @@ class SendableChooser : public SendableChooserBase {
    * @param name   the name of the option
    * @param object the option
    */
-  void SetDefaultOption(wpi::StringRef name, T object);
+  void SetDefaultOption(std::string_view name, T object);
 
   /**
    * Adds the given object to the list of options.
@@ -75,13 +75,13 @@ class SendableChooser : public SendableChooserBase {
    * On the SmartDashboard on the desktop, the object will appear as the given
    * name.
    *
-   * @deprecated use AddOption(wpi::StringRef name, T object) instead.
+   * @deprecated use AddOption(std::string_view name, T object) instead.
    *
    * @param name   the name of the option
    * @param object the option
    */
   WPI_DEPRECATED("use AddOption() instead")
-  void AddObject(wpi::StringRef name, T object) { AddOption(name, object); }
+  void AddObject(std::string_view name, T object) { AddOption(name, object); }
 
   /**
    * Add the given object to the list of options and marks it as the default.
@@ -89,13 +89,13 @@ class SendableChooser : public SendableChooserBase {
    * Functionally, this is very close to AddOption() except that it will use
    * this as the default option if none other is explicitly selected.
    *
-   * @deprecated use SetDefaultOption(wpi::StringRef name, T object) instead.
+   * @deprecated use SetDefaultOption(std::string_view name, T object) instead.
    *
    * @param name   the name of the option
    * @param object the option
    */
   WPI_DEPRECATED("use SetDefaultOption() instead")
-  void AddDefault(wpi::StringRef name, T object) {
+  void AddDefault(std::string_view name, T object) {
     SetDefaultOption(name, object);
   }
 
diff --git a/wpilibc/src/main/native/include/frc/smartdashboard/SendableChooser.inc b/wpilibc/src/main/native/include/frc/smartdashboard/SendableChooser.inc
index 2e160bcf32..d556ea3aad 100644
--- a/wpilibc/src/main/native/include/frc/smartdashboard/SendableChooser.inc
+++ b/wpilibc/src/main/native/include/frc/smartdashboard/SendableChooser.inc
@@ -7,22 +7,21 @@
 #include <algorithm>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
-#include <wpi/StringRef.h>
-
 #include "frc/smartdashboard/SendableChooser.h"
 
 namespace frc {
 
 template <class T>
-void SendableChooser<T>::AddOption(wpi::StringRef name, T object) {
+void SendableChooser<T>::AddOption(std::string_view name, T object) {
   m_choices[name] = std::move(object);
 }
 
 template <class T>
-void SendableChooser<T>::SetDefaultOption(wpi::StringRef name, T object) {
+void SendableChooser<T>::SetDefaultOption(std::string_view name, T object) {
   m_defaultChoice = name;
   AddOption(name, std::move(object));
 }
@@ -53,7 +52,7 @@ void SendableChooser<T>::InitSendable(SendableBuilder& builder) {
       [=]() {
         std::vector<std::string> keys;
         for (const auto& choice : m_choices) {
-          keys.push_back(choice.first());
+          keys.emplace_back(choice.first());
         }
 
         // Unlike std::map, wpi::StringMap elements
@@ -65,17 +64,17 @@ void SendableChooser<T>::InitSendable(SendableBuilder& builder) {
       nullptr);
   builder.AddSmallStringProperty(
       kDefault,
-      [=](wpi::SmallVectorImpl<char>&) -> wpi::StringRef {
+      [=](wpi::SmallVectorImpl<char>&) -> std::string_view {
         return m_defaultChoice;
       },
       nullptr);
   builder.AddSmallStringProperty(
       kActive,
-      [=](wpi::SmallVectorImpl<char>& buf) -> wpi::StringRef {
+      [=](wpi::SmallVectorImpl<char>& buf) -> std::string_view {
         std::scoped_lock lock(m_mutex);
         if (m_haveSelected) {
           buf.assign(m_selected.begin(), m_selected.end());
-          return wpi::StringRef(buf.data(), buf.size());
+          return {buf.data(), buf.size()};
         } else {
           return m_defaultChoice;
         }
@@ -85,7 +84,7 @@ void SendableChooser<T>::InitSendable(SendableBuilder& builder) {
     std::scoped_lock lock(m_mutex);
     m_activeEntries.emplace_back(builder.GetEntry(kActive));
   }
-  builder.AddStringProperty(kSelected, nullptr, [=](wpi::StringRef val) {
+  builder.AddStringProperty(kSelected, nullptr, [=](std::string_view val) {
     std::scoped_lock lock(m_mutex);
     m_haveSelected = true;
     m_selected = val;
diff --git a/wpilibc/src/main/native/include/frc/smartdashboard/SendableRegistry.h b/wpilibc/src/main/native/include/frc/smartdashboard/SendableRegistry.h
index b1c9b35f32..e93d77a613 100644
--- a/wpilibc/src/main/native/include/frc/smartdashboard/SendableRegistry.h
+++ b/wpilibc/src/main/native/include/frc/smartdashboard/SendableRegistry.h
@@ -298,8 +298,8 @@ class SendableRegistry {
    * Data passed to ForeachLiveWindow() callback function
    */
   struct CallbackData {
-    CallbackData(Sendable* sendable_, wpi::StringRef name_,
-                 wpi::StringRef subsystem_, Sendable* parent_,
+    CallbackData(Sendable* sendable_, std::string_view name_,
+                 std::string_view subsystem_, Sendable* parent_,
                  std::shared_ptr<void>& data_, SendableBuilderImpl& builder_)
         : sendable(sendable_),
           name(name_),
@@ -309,8 +309,8 @@ class SendableRegistry {
           builder(builder_) {}
 
     Sendable* sendable;
-    wpi::StringRef name;
-    wpi::StringRef subsystem;
+    std::string_view name;
+    std::string_view subsystem;
     Sendable* parent;
     std::shared_ptr<void>& data;
     SendableBuilderImpl& builder;
diff --git a/wpilibc/src/main/native/include/frc/smartdashboard/SmartDashboard.h b/wpilibc/src/main/native/include/frc/smartdashboard/SmartDashboard.h
index 6a6ee299cf..1ce7762392 100644
--- a/wpilibc/src/main/native/include/frc/smartdashboard/SmartDashboard.h
+++ b/wpilibc/src/main/native/include/frc/smartdashboard/SmartDashboard.h
@@ -6,6 +6,7 @@
 
 #include <memory>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #include <networktables/NetworkTableEntry.h>
@@ -27,7 +28,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param key the key to search for
    * @return true if the table as a value assigned to the given key
    */
-  static bool ContainsKey(wpi::StringRef key);
+  static bool ContainsKey(std::string_view key);
 
   /**
    * @param types bitmask of types; 0 is treated as a "don't care".
@@ -40,7 +41,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    *
    * @param key the key to make persistent
    */
-  static void SetPersistent(wpi::StringRef key);
+  static void SetPersistent(std::string_view key);
 
   /**
    * Stop making a key's value persistent through program restarts.
@@ -48,7 +49,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    *
    * @param key the key name
    */
-  static void ClearPersistent(wpi::StringRef key);
+  static void ClearPersistent(std::string_view key);
 
   /**
    * Returns whether the value is persistent through program restarts.
@@ -56,7 +57,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    *
    * @param key the key name
    */
-  static bool IsPersistent(wpi::StringRef key);
+  static bool IsPersistent(std::string_view key);
 
   /**
    * Sets flags on the specified key in this table. The key can
@@ -65,7 +66,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param key the key name
    * @param flags the flags to set (bitmask)
    */
-  static void SetFlags(wpi::StringRef key, unsigned int flags);
+  static void SetFlags(std::string_view key, unsigned int flags);
 
   /**
    * Clears flags on the specified key in this table. The key can
@@ -74,7 +75,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param key the key name
    * @param flags the flags to clear (bitmask)
    */
-  static void ClearFlags(wpi::StringRef key, unsigned int flags);
+  static void ClearFlags(std::string_view key, unsigned int flags);
 
   /**
    * Returns the flags for the specified key.
@@ -82,14 +83,14 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param key the key name
    * @return the flags, or 0 if the key is not defined
    */
-  static unsigned int GetFlags(wpi::StringRef key);
+  static unsigned int GetFlags(std::string_view key);
 
   /**
    * Deletes the specified key in this table.
    *
    * @param key the key name
    */
-  static void Delete(wpi::StringRef key);
+  static void Delete(std::string_view key);
 
   /**
    * Returns an NT Entry mapping to the specified key
@@ -99,7 +100,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param key the key
    * @return    the entry for the key
    */
-  static nt::NetworkTableEntry GetEntry(wpi::StringRef key);
+  static nt::NetworkTableEntry GetEntry(std::string_view key);
 
   /**
    * Maps the specified key to the specified value in this table.
@@ -113,7 +114,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param keyName the key
    * @param value   the value
    */
-  static void PutData(wpi::StringRef key, Sendable* data);
+  static void PutData(std::string_view key, Sendable* data);
 
   /**
    * Maps the specified key (where the key is the name of the Sendable)
@@ -135,7 +136,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param keyName the key
    * @return the value
    */
-  static Sendable* GetData(wpi::StringRef keyName);
+  static Sendable* GetData(std::string_view keyName);
 
   /**
    * Maps the specified key to the specified value in this table.
@@ -147,7 +148,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param value   the value
    * @return        False if the table key already exists with a different type
    */
-  static bool PutBoolean(wpi::StringRef keyName, bool value);
+  static bool PutBoolean(std::string_view keyName, bool value);
 
   /**
    * Gets the current value in the table, setting it if it does not exist.
@@ -155,7 +156,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param defaultValue the default value to set if key doesn't exist.
    * @returns False if the table key exists with a different type
    */
-  static bool SetDefaultBoolean(wpi::StringRef key, bool defaultValue);
+  static bool SetDefaultBoolean(std::string_view key, bool defaultValue);
 
   /**
    * Returns the value at the specified key.
@@ -165,7 +166,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param keyName the key
    * @return the value
    */
-  static bool GetBoolean(wpi::StringRef keyName, bool defaultValue);
+  static bool GetBoolean(std::string_view keyName, bool defaultValue);
 
   /**
    * Maps the specified key to the specified value in this table.
@@ -177,7 +178,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param value   the value
    * @return        False if the table key already exists with a different type
    */
-  static bool PutNumber(wpi::StringRef keyName, double value);
+  static bool PutNumber(std::string_view keyName, double value);
 
   /**
    * Gets the current value in the table, setting it if it does not exist.
@@ -186,7 +187,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param defaultValue The default value to set if key doesn't exist.
    * @returns False if the table key exists with a different type
    */
-  static bool SetDefaultNumber(wpi::StringRef key, double defaultValue);
+  static bool SetDefaultNumber(std::string_view key, double defaultValue);
 
   /**
    * Returns the value at the specified key.
@@ -196,7 +197,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param keyName the key
    * @return the value
    */
-  static double GetNumber(wpi::StringRef keyName, double defaultValue);
+  static double GetNumber(std::string_view keyName, double defaultValue);
 
   /**
    * Maps the specified key to the specified value in this table.
@@ -208,7 +209,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param value   the value
    * @return        False if the table key already exists with a different type
    */
-  static bool PutString(wpi::StringRef keyName, wpi::StringRef value);
+  static bool PutString(std::string_view keyName, std::string_view value);
 
   /**
    * Gets the current value in the table, setting it if it does not exist.
@@ -217,7 +218,8 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param defaultValue the default value to set if key doesn't exist.
    * @returns False if the table key exists with a different type
    */
-  static bool SetDefaultString(wpi::StringRef key, wpi::StringRef defaultValue);
+  static bool SetDefaultString(std::string_view key,
+                               std::string_view defaultValue);
 
   /**
    * Returns the value at the specified key.
@@ -227,8 +229,8 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param keyName the key
    * @return the value
    */
-  static std::string GetString(wpi::StringRef keyName,
-                               wpi::StringRef defaultValue);
+  static std::string GetString(std::string_view keyName,
+                               std::string_view defaultValue);
 
   /**
    * Put a boolean array in the table.
@@ -241,7 +243,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    *       std::vector<bool> is special-cased in C++. 0 is false, any
    *       non-zero value is true.
    */
-  static bool PutBooleanArray(wpi::StringRef key, wpi::ArrayRef<int> value);
+  static bool PutBooleanArray(std::string_view key, wpi::ArrayRef<int> value);
 
   /**
    * Gets the current value in the table, setting it if it does not exist.
@@ -250,7 +252,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param defaultValue the default value to set if key doesn't exist.
    * @returns False if the table key exists with a different type
    */
-  static bool SetDefaultBooleanArray(wpi::StringRef key,
+  static bool SetDefaultBooleanArray(std::string_view key,
                                      wpi::ArrayRef<int> defaultValue);
 
   /**
@@ -271,7 +273,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    *       because std::vector<bool> is special-cased in C++. 0 is false, any
    *       non-zero value is true.
    */
-  static std::vector<int> GetBooleanArray(wpi::StringRef key,
+  static std::vector<int> GetBooleanArray(std::string_view key,
                                           wpi::ArrayRef<int> defaultValue);
 
   /**
@@ -281,7 +283,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param value The value that will be assigned.
    * @return False if the table key already exists with a different type
    */
-  static bool PutNumberArray(wpi::StringRef key, wpi::ArrayRef<double> value);
+  static bool PutNumberArray(std::string_view key, wpi::ArrayRef<double> value);
 
   /**
    * Gets the current value in the table, setting it if it does not exist.
@@ -290,7 +292,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param defaultValue The default value to set if key doesn't exist.
    * @returns False if the table key exists with a different type
    */
-  static bool SetDefaultNumberArray(wpi::StringRef key,
+  static bool SetDefaultNumberArray(std::string_view key,
                                     wpi::ArrayRef<double> defaultValue);
 
   /**
@@ -307,7 +309,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @note This makes a copy of the array. If the overhead of this is a concern,
    *       use GetValue() instead.
    */
-  static std::vector<double> GetNumberArray(wpi::StringRef key,
+  static std::vector<double> GetNumberArray(std::string_view key,
                                             wpi::ArrayRef<double> defaultValue);
 
   /**
@@ -317,7 +319,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param value The value that will be assigned.
    * @return False if the table key already exists with a different type
    */
-  static bool PutStringArray(wpi::StringRef key,
+  static bool PutStringArray(std::string_view key,
                              wpi::ArrayRef<std::string> value);
 
   /**
@@ -327,7 +329,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param defaultValue The default value to set if key doesn't exist.
    * @returns False if the table key exists with a different type
    */
-  static bool SetDefaultStringArray(wpi::StringRef key,
+  static bool SetDefaultStringArray(std::string_view key,
                                     wpi::ArrayRef<std::string> defaultValue);
 
   /**
@@ -345,7 +347,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    *       use GetValue() instead.
    */
   static std::vector<std::string> GetStringArray(
-      wpi::StringRef key, wpi::ArrayRef<std::string> defaultValue);
+      std::string_view key, wpi::ArrayRef<std::string> defaultValue);
 
   /**
    * Put a raw value (byte array) in the table.
@@ -354,7 +356,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param value The value that will be assigned.
    * @return False if the table key already exists with a different type
    */
-  static bool PutRaw(wpi::StringRef key, wpi::StringRef value);
+  static bool PutRaw(std::string_view key, std::string_view value);
 
   /**
    * Gets the current value in the table, setting it if it does not exist.
@@ -363,7 +365,8 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param defaultValue The default value to set if key doesn't exist.
    * @returns False if the table key exists with a different type
    */
-  static bool SetDefaultRaw(wpi::StringRef key, wpi::StringRef defaultValue);
+  static bool SetDefaultRaw(std::string_view key,
+                            std::string_view defaultValue);
 
   /**
    * Returns the raw value (byte array) the key maps to.
@@ -379,7 +382,8 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @note This makes a copy of the raw contents. If the overhead of this is a
    *       concern, use GetValue() instead.
    */
-  static std::string GetRaw(wpi::StringRef key, wpi::StringRef defaultValue);
+  static std::string GetRaw(std::string_view key,
+                            std::string_view defaultValue);
 
   /**
    * Maps the specified key to the specified complex value (such as an array) in
@@ -392,7 +396,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param value   the value
    * @return        False if the table key already exists with a different type
    */
-  static bool PutValue(wpi::StringRef keyName,
+  static bool PutValue(std::string_view keyName,
                        std::shared_ptr<nt::Value> value);
 
   /**
@@ -402,7 +406,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param defaultValue The default value to set if key doesn't exist.
    * @returns False if the table key exists with a different type
    */
-  static bool SetDefaultValue(wpi::StringRef key,
+  static bool SetDefaultValue(std::string_view key,
                               std::shared_ptr<nt::Value> defaultValue);
 
   /**
@@ -412,7 +416,7 @@ class SmartDashboard : public Sendable, public SendableHelper<SmartDashboard> {
    * @param keyName the key
    * @param value   the object to retrieve the value into
    */
-  static std::shared_ptr<nt::Value> GetValue(wpi::StringRef keyName);
+  static std::shared_ptr<nt::Value> GetValue(std::string_view keyName);
 
   /**
    * Posts a task from a listener to the ListenerExecutor, so that it can be run
diff --git a/wpilibc/src/test/native/cpp/ScopedTracerTest.cpp b/wpilibc/src/test/native/cpp/ScopedTracerTest.cpp
index 8ffb51e587..c4ef317404 100644
--- a/wpilibc/src/test/native/cpp/ScopedTracerTest.cpp
+++ b/wpilibc/src/test/native/cpp/ScopedTracerTest.cpp
@@ -2,18 +2,20 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
+#include <string_view>
+
 #include <wpi/SmallString.h>
-#include <wpi/StringRef.h>
+#include <wpi/StringExtras.h>
 #include <wpi/raw_ostream.h>
 
 #include "frc/ScopedTracer.h"
 #include "frc/simulation/SimHooks.h"
 #include "gtest/gtest.h"
 
-wpi::SmallString<128> buf;
-wpi::raw_svector_ostream os(buf);
-
 TEST(ScopedTracerTest, Timing) {
+  wpi::SmallString<128> buf;
+  wpi::raw_svector_ostream os(buf);
+
   frc::sim::PauseTiming();
   {
     frc::ScopedTracer tracer("timing_test", os);
@@ -21,6 +23,6 @@ TEST(ScopedTracerTest, Timing) {
   }
   frc::sim::ResumeTiming();
 
-  wpi::StringRef out = os.str();
-  EXPECT_TRUE(out.startswith("	timing_test: 1.5"));
+  std::string_view out = os.str();
+  EXPECT_TRUE(wpi::starts_with(out, "	timing_test: 1.5"));
 }
diff --git a/wpilibc/src/test/native/cpp/shuffleboard/MockActuatorSendable.cpp b/wpilibc/src/test/native/cpp/shuffleboard/MockActuatorSendable.cpp
index 51b2193d1c..6d7897eb5e 100644
--- a/wpilibc/src/test/native/cpp/shuffleboard/MockActuatorSendable.cpp
+++ b/wpilibc/src/test/native/cpp/shuffleboard/MockActuatorSendable.cpp
@@ -6,10 +6,12 @@
 
 #include "frc/smartdashboard/SendableRegistry.h"
 
+using namespace frc;
+
 MockActuatorSendable::MockActuatorSendable(std::string_view name) {
-  frc::SendableRegistry::GetInstance().Add(this, name);
+  SendableRegistry::GetInstance().Add(this, name);
 }
 
-void MockActuatorSendable::InitSendable(frc::SendableBuilder& builder) {
+void MockActuatorSendable::InitSendable(SendableBuilder& builder) {
   builder.SetActuator(true);
 }
diff --git a/wpilibc/src/test/native/cpp/shuffleboard/SuppliedValueWidgetTest.cpp b/wpilibc/src/test/native/cpp/shuffleboard/SuppliedValueWidgetTest.cpp
index 94aa5caf16..c8449e5be7 100644
--- a/wpilibc/src/test/native/cpp/shuffleboard/SuppliedValueWidgetTest.cpp
+++ b/wpilibc/src/test/native/cpp/shuffleboard/SuppliedValueWidgetTest.cpp
@@ -97,7 +97,7 @@ TEST_F(SuppliedValueWidgetTest, AddBooleanArray) {
 }
 
 TEST_F(SuppliedValueWidgetTest, AddRaw) {
-  wpi::StringRef bytes = "\1\2\3";
+  std::string_view bytes = "\1\2\3";
   m_tab->AddRaw("Raw", [&bytes]() { return bytes; });
   auto entry = m_ntInst.inst.GetEntry("/Shuffleboard/Tab/Raw");
 
diff --git a/wpilibc/src/test/native/cpp/simulation/AccelerometerSimTest.cpp b/wpilibc/src/test/native/cpp/simulation/AccelerometerSimTest.cpp
index 4534ff3294..1a59604b1e 100644
--- a/wpilibc/src/test/native/cpp/simulation/AccelerometerSimTest.cpp
+++ b/wpilibc/src/test/native/cpp/simulation/AccelerometerSimTest.cpp
@@ -22,7 +22,7 @@ TEST(AcclerometerSimTests, TestActiveCallback) {
   bool lastValue = false;
 
   auto cb = sim.RegisterActiveCallback(
-      [&](wpi::StringRef name, const HAL_Value* value) {
+      [&](std::string_view name, const HAL_Value* value) {
         wasTriggered = true;
         lastValue = value->data.v_boolean;
       },
diff --git a/wpilibc/src/test/native/cpp/simulation/SimDeviceSimTest.cpp b/wpilibc/src/test/native/cpp/simulation/SimDeviceSimTest.cpp
index 90420c6f7e..d195ee7d56 100644
--- a/wpilibc/src/test/native/cpp/simulation/SimDeviceSimTest.cpp
+++ b/wpilibc/src/test/native/cpp/simulation/SimDeviceSimTest.cpp
@@ -2,8 +2,9 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
+#include <string_view>
+
 #include <hal/SimDevice.h>
-#include <wpi/StringRef.h>
 
 #include "frc/simulation/SimDeviceSim.h"
 #include "gtest/gtest.h"
@@ -27,7 +28,7 @@ TEST(SimDeviceSimTests, TestEnumerateDevices) {
   bool foundit = false;
   SimDeviceSim::EnumerateDevices(
       "te", [&](const char* name, HAL_SimDeviceHandle handle) {
-        if (wpi::StringRef(name) == "test") {
+        if (std::string_view(name) == "test") {
           foundit = true;
         }
       });
diff --git a/wpilibcExamples/src/main/cpp/examples/IntermediateVision/cpp/Robot.cpp b/wpilibcExamples/src/main/cpp/examples/IntermediateVision/cpp/Robot.cpp
index 923b4253cc..f8a01e84d7 100644
--- a/wpilibcExamples/src/main/cpp/examples/IntermediateVision/cpp/Robot.cpp
+++ b/wpilibcExamples/src/main/cpp/examples/IntermediateVision/cpp/Robot.cpp
@@ -2,6 +2,7 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
+#include <cstdio>
 #include <thread>
 
 #include <cameraserver/CameraServer.h>
@@ -9,7 +10,6 @@
 #include <opencv2/core/core.hpp>
 #include <opencv2/core/types.hpp>
 #include <opencv2/imgproc/imgproc.hpp>
-#include <wpi/raw_ostream.h>
 
 /**
  * This is a demo program showing the use of OpenCV to do vision processing. The
@@ -18,7 +18,7 @@
  * processing.
  */
 class Robot : public frc::TimedRobot {
-#if defined(__linux__)
+#if defined(__linux__) || defined(_WIN32)
 
  private:
   static void VisionThread() {
@@ -60,12 +60,12 @@ class Robot : public frc::TimedRobot {
   void RobotInit() override {
     // We need to run our vision program in a separate thread. If not, our robot
     // program will not run.
-#if defined(__linux__)
+#if defined(__linux__) || defined(_WIN32)
     std::thread visionThread(VisionThread);
     visionThread.detach();
 #else
-    wpi::errs() << "Vision only available on Linux.\n";
-    wpi::errs().flush();
+    std::fputs("Vision only available on Linux or Windows.\n", stderr);
+    std::fflush(stderr);
 #endif
   }
 };
diff --git a/wpilibcExamples/src/main/cpp/examples/QuickVision/cpp/Robot.cpp b/wpilibcExamples/src/main/cpp/examples/QuickVision/cpp/Robot.cpp
index b754deb277..c1d7c10fea 100644
--- a/wpilibcExamples/src/main/cpp/examples/QuickVision/cpp/Robot.cpp
+++ b/wpilibcExamples/src/main/cpp/examples/QuickVision/cpp/Robot.cpp
@@ -2,9 +2,10 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
+#include <cstdio>
+
 #include <cameraserver/CameraServer.h>
 #include <frc/TimedRobot.h>
-#include <wpi/raw_ostream.h>
 
 /**
  * Uses the CameraServer class to automatically capture video from a USB webcam
@@ -15,11 +16,11 @@
 class Robot : public frc::TimedRobot {
  public:
   void RobotInit() override {
-#if defined(__linux__)
+#if defined(__linux__) || defined(_WIN32)
     frc::CameraServer::GetInstance()->StartAutomaticCapture();
 #else
-    wpi::errs() << "Vision only available on Linux.\n";
-    wpi::errs().flush();
+    std::fputs("Vision only available on Linux or Windows.\n", stderr);
+    std::fflush(stderr);
 #endif
   }
 };
diff --git a/wpimath/src/main/native/cpp/trajectory/TrajectoryGenerator.cpp b/wpimath/src/main/native/cpp/trajectory/TrajectoryGenerator.cpp
index 73d23dcb9d..2e2771daca 100644
--- a/wpimath/src/main/native/cpp/trajectory/TrajectoryGenerator.cpp
+++ b/wpimath/src/main/native/cpp/trajectory/TrajectoryGenerator.cpp
@@ -6,7 +6,7 @@
 
 #include <utility>
 
-#include <wpi/raw_ostream.h>
+#include <fmt/format.h>
 
 #include "frc/spline/SplineHelper.h"
 #include "frc/spline/SplineParameterizer.h"
@@ -22,7 +22,7 @@ void TrajectoryGenerator::ReportError(const char* error) {
   if (s_errorFunc) {
     s_errorFunc(error);
   } else {
-    wpi::errs() << "TrajectoryGenerator error: " << error << "\n";
+    fmt::print(stderr, "TrajectoryGenerator error: {}\n", error);
   }
 }
 
diff --git a/wpimath/src/main/native/cpp/trajectory/TrajectoryUtil.cpp b/wpimath/src/main/native/cpp/trajectory/TrajectoryUtil.cpp
index 3a1f3170cd..29e27ec430 100644
--- a/wpimath/src/main/native/cpp/trajectory/TrajectoryUtil.cpp
+++ b/wpimath/src/main/native/cpp/trajectory/TrajectoryUtil.cpp
@@ -6,6 +6,7 @@
 
 #include <system_error>
 
+#include <fmt/format.h>
 #include <wpi/SmallString.h>
 #include <wpi/json.h>
 #include <wpi/raw_istream.h>
@@ -14,13 +15,12 @@
 using namespace frc;
 
 void TrajectoryUtil::ToPathweaverJson(const Trajectory& trajectory,
-                                      const wpi::Twine& path) {
+                                      std::string_view path) {
   std::error_code error_code;
 
-  wpi::SmallString<128> buf;
-  wpi::raw_fd_ostream output{path.toStringRef(buf), error_code};
+  wpi::raw_fd_ostream output{path, error_code};
   if (error_code) {
-    throw std::runtime_error(("Cannot open file: " + path).str());
+    throw std::runtime_error(fmt::format("Cannot open file: {}", path));
   }
 
   wpi::json json = trajectory.States();
@@ -28,13 +28,12 @@ void TrajectoryUtil::ToPathweaverJson(const Trajectory& trajectory,
   output.flush();
 }
 
-Trajectory TrajectoryUtil::FromPathweaverJson(const wpi::Twine& path) {
+Trajectory TrajectoryUtil::FromPathweaverJson(std::string_view path) {
   std::error_code error_code;
 
-  wpi::SmallString<128> buf;
-  wpi::raw_fd_istream input{path.toStringRef(buf), error_code};
+  wpi::raw_fd_istream input{path, error_code};
   if (error_code) {
-    throw std::runtime_error(("Cannot open file: " + path).str());
+    throw std::runtime_error(fmt::format("Cannot open file: {}", path));
   }
 
   wpi::json json;
@@ -48,8 +47,7 @@ std::string TrajectoryUtil::SerializeTrajectory(const Trajectory& trajectory) {
   return json.dump();
 }
 
-Trajectory TrajectoryUtil::DeserializeTrajectory(
-    const wpi::StringRef json_str) {
+Trajectory TrajectoryUtil::DeserializeTrajectory(std::string_view json_str) {
   wpi::json json = wpi::json::parse(json_str);
   return Trajectory{json.get<std::vector<Trajectory::State>>()};
 }
diff --git a/wpimath/src/main/native/include/frc/spline/SplineParameterizer.h b/wpimath/src/main/native/include/frc/spline/SplineParameterizer.h
index efbf989932..b174b53748 100644
--- a/wpimath/src/main/native/include/frc/spline/SplineParameterizer.h
+++ b/wpimath/src/main/native/include/frc/spline/SplineParameterizer.h
@@ -33,8 +33,6 @@
 #include <utility>
 #include <vector>
 
-#include <wpi/Twine.h>
-
 #include "frc/spline/Spline.h"
 #include "units/angle.h"
 #include "units/curvature.h"
diff --git a/wpimath/src/main/native/include/frc/trajectory/TrajectoryUtil.h b/wpimath/src/main/native/include/frc/trajectory/TrajectoryUtil.h
index 69482b8f73..612e8b2b6e 100644
--- a/wpimath/src/main/native/include/frc/trajectory/TrajectoryUtil.h
+++ b/wpimath/src/main/native/include/frc/trajectory/TrajectoryUtil.h
@@ -5,9 +5,7 @@
 #pragma once
 
 #include <string>
-
-#include <wpi/StringRef.h>
-#include <wpi/Twine.h>
+#include <string_view>
 
 #include "frc/trajectory/Trajectory.h"
 
@@ -25,7 +23,7 @@ class TrajectoryUtil {
    * @return The interpolated state.
    */
   static void ToPathweaverJson(const Trajectory& trajectory,
-                               const wpi::Twine& path);
+                               std::string_view path);
   /**
    * Imports a Trajectory from a PathWeaver-style JSON file.
    *
@@ -33,7 +31,7 @@ class TrajectoryUtil {
    *
    * @return The trajectory represented by the file.
    */
-  static Trajectory FromPathweaverJson(const wpi::Twine& path);
+  static Trajectory FromPathweaverJson(std::string_view path);
 
   /**
    * Deserializes a Trajectory from PathWeaver-style JSON.
@@ -51,6 +49,6 @@ class TrajectoryUtil {
    *
    * @return the string containing the serialized JSON
    */
-  static Trajectory DeserializeTrajectory(wpi::StringRef json_str);
+  static Trajectory DeserializeTrajectory(std::string_view json_str);
 };
 }  // namespace frc
diff --git a/wpiutil/examples/webserver/webserver.cpp b/wpiutil/examples/webserver/webserver.cpp
index 1147c686f3..503405f208 100644
--- a/wpiutil/examples/webserver/webserver.cpp
+++ b/wpiutil/examples/webserver/webserver.cpp
@@ -4,10 +4,10 @@
 
 #include <cstdio>
 
+#include "fmt/format.h"
 #include "wpi/EventLoopRunner.h"
 #include "wpi/HttpServerConnection.h"
 #include "wpi/UrlParser.h"
-#include "wpi/raw_ostream.h"
 #include "wpi/uv/Loop.h"
 #include "wpi/uv/Tcp.h"
 
@@ -23,7 +23,7 @@ class MyHttpServerConnection : public wpi::HttpServerConnection {
 };
 
 void MyHttpServerConnection::ProcessRequest() {
-  wpi::errs() << "HTTP request: '" << m_request.GetUrl() << "'\n";
+  fmt::print(stderr, "HTTP request: '{}'\n", m_request.GetUrl());
   wpi::UrlParser url{m_request.GetUrl(),
                      m_request.GetMethod() == wpi::HTTP_CONNECT};
   if (!url.IsValid()) {
@@ -32,27 +32,25 @@ void MyHttpServerConnection::ProcessRequest() {
     return;
   }
 
-  wpi::StringRef path;
+  std::string_view path;
   if (url.HasPath()) {
     path = url.GetPath();
   }
-  wpi::errs() << "path: \"" << path << "\"\n";
+  fmt::print(stderr, "path: \"{}\"\n", path);
 
-  wpi::StringRef query;
+  std::string_view query;
   if (url.HasQuery()) {
     query = url.GetQuery();
   }
-  wpi::errs() << "query: \"" << query << "\"\n";
+  fmt::print(stderr, "query: \"{}\"\n", query);
 
   const bool isGET = m_request.GetMethod() == wpi::HTTP_GET;
-  if (isGET && path.equals("/")) {
+  if (isGET && path == "/") {
     // build HTML root page
-    wpi::SmallString<256> buf;
-    wpi::raw_svector_ostream os{buf};
-    os << "<html><head><title>WebServer Example</title></head>";
-    os << "<body><p>This is an example root page from the webserver.";
-    os << "</body></html>";
-    SendResponse(200, "OK", "text/html", os.str());
+    SendResponse(200, "OK", "text/html",
+                 "<html><head><title>WebServer Example</title></head>"
+                 "<body><p>This is an example root page from the webserver."
+                 "</body></html>");
   } else {
     SendError(404, "Resource not found");
   }
@@ -73,7 +71,7 @@ int main() {
       if (!tcp) {
         return;
       }
-      wpi::errs() << "Got a connection\n";
+      std::fputs("Got a connection\n", stderr);
       auto conn = std::make_shared<MyHttpServerConnection>(tcp);
       tcp->SetData(conn);
     });
@@ -81,7 +79,7 @@ int main() {
     // start listening for incoming connections
     tcp->Listen();
 
-    wpi::errs() << "Listening on port 8080\n";
+    std::fputs("Listening on port 8080\n", stderr);
   });
 
   // wait for a keypress to terminate
diff --git a/wpiutil/src/dev/native/cpp/main.cpp b/wpiutil/src/dev/native/cpp/main.cpp
index fd3686cd6f..ede6910134 100644
--- a/wpiutil/src/dev/native/cpp/main.cpp
+++ b/wpiutil/src/dev/native/cpp/main.cpp
@@ -4,11 +4,10 @@
 
 #include <iostream>
 
-#include "wpi/SmallVector.h"
-#include "wpi/StringRef.h"
+#include "wpi/SmallString.h"
 #include "wpi/hostname.h"
 
 int main() {
-  wpi::StringRef v1("Hello");
-  std::cout << v1.lower() << std::endl;
+  wpi::SmallString<128> v1("Hello");
+  std::cout << v1.str() << std::endl;
 }
diff --git a/wpiutil/src/main/native/cpp/Base64.cpp b/wpiutil/src/main/native/cpp/Base64.cpp
index 4d13b1a613..08c9fce9ce 100644
--- a/wpiutil/src/main/native/cpp/Base64.cpp
+++ b/wpiutil/src/main/native/cpp/Base64.cpp
@@ -80,17 +80,19 @@ static const unsigned char pr2six[256] = {
     64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64,
     64, 64, 64, 64, 64, 64, 64, 64, 64};
 
-size_t Base64Decode(raw_ostream& os, StringRef encoded) {
-  const unsigned char* end = encoded.bytes_begin();
-  while (pr2six[*end] <= 63 && end != encoded.bytes_end()) {
+size_t Base64Decode(raw_ostream& os, std::string_view encoded) {
+  auto bytes_begin = reinterpret_cast<const unsigned char*>(encoded.data());
+  auto bytes_end = bytes_begin + encoded.size();
+  const unsigned char* end = bytes_begin;
+  while (pr2six[*end] <= 63 && end != bytes_end) {
     ++end;
   }
-  size_t nprbytes = end - encoded.bytes_begin();
+  size_t nprbytes = end - bytes_begin;
   if (nprbytes == 0) {
     return 0;
   }
 
-  const unsigned char* cur = encoded.bytes_begin();
+  const unsigned char* cur = bytes_begin;
 
   while (nprbytes > 4) {
     os << static_cast<unsigned char>(pr2six[cur[0]] << 2 | pr2six[cur[1]] >> 4);
@@ -111,10 +113,10 @@ size_t Base64Decode(raw_ostream& os, StringRef encoded) {
     os << static_cast<unsigned char>(pr2six[cur[2]] << 6 | pr2six[cur[3]]);
   }
 
-  return (end - encoded.bytes_begin()) + ((4 - nprbytes) & 3);
+  return (end - bytes_begin) + ((4 - nprbytes) & 3);
 }
 
-size_t Base64Decode(StringRef encoded, std::string* plain) {
+size_t Base64Decode(std::string_view encoded, std::string* plain) {
   plain->resize(0);
   raw_string_ostream os(*plain);
   size_t rv = Base64Decode(os, encoded);
@@ -122,8 +124,8 @@ size_t Base64Decode(StringRef encoded, std::string* plain) {
   return rv;
 }
 
-StringRef Base64Decode(StringRef encoded, size_t* num_read,
-                       SmallVectorImpl<char>& buf) {
+std::string_view Base64Decode(std::string_view encoded, size_t* num_read,
+                              SmallVectorImpl<char>& buf) {
   buf.clear();
   raw_svector_ostream os(buf);
   *num_read = Base64Decode(os, encoded);
@@ -133,7 +135,7 @@ StringRef Base64Decode(StringRef encoded, size_t* num_read,
 static const char basis_64[] =
     "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 
-void Base64Encode(raw_ostream& os, StringRef plain) {
+void Base64Encode(raw_ostream& os, std::string_view plain) {
   if (plain.empty()) {
     return;
   }
@@ -162,14 +164,15 @@ void Base64Encode(raw_ostream& os, StringRef plain) {
   }
 }
 
-void Base64Encode(StringRef plain, std::string* encoded) {
+void Base64Encode(std::string_view plain, std::string* encoded) {
   encoded->resize(0);
   raw_string_ostream os(*encoded);
   Base64Encode(os, plain);
   os.flush();
 }
 
-StringRef Base64Encode(StringRef plain, SmallVectorImpl<char>& buf) {
+std::string_view Base64Encode(std::string_view plain,
+                              SmallVectorImpl<char>& buf) {
   buf.clear();
   raw_svector_ostream os(buf);
   Base64Encode(os, plain);
diff --git a/wpiutil/src/main/native/cpp/HttpParser.cpp b/wpiutil/src/main/native/cpp/HttpParser.cpp
index 4733befb48..3c18e0f6f8 100644
--- a/wpiutil/src/main/native/cpp/HttpParser.cpp
+++ b/wpiutil/src/main/native/cpp/HttpParser.cpp
@@ -37,7 +37,7 @@ HttpParser::HttpParser(Type type) {
     if ((self.m_urlBuf.size() + length) > self.m_maxLength) {
       return 1;
     }
-    self.m_urlBuf += StringRef{at, length};
+    self.m_urlBuf += std::string_view{at, length};
     self.m_state = kUrl;
     return 0;
   };
@@ -50,7 +50,7 @@ HttpParser::HttpParser(Type type) {
     if ((self.m_valueBuf.size() + length) > self.m_maxLength) {
       return 1;
     }
-    self.m_valueBuf += StringRef{at, length};
+    self.m_valueBuf += std::string_view{at, length};
     self.m_state = kStatus;
     return 0;
   };
@@ -95,7 +95,7 @@ HttpParser::HttpParser(Type type) {
     if ((self.m_fieldBuf.size() + length) > self.m_maxLength) {
       return 1;
     }
-    self.m_fieldBuf += StringRef{at, length};
+    self.m_fieldBuf += std::string_view{at, length};
     return 0;
   };
 
@@ -114,7 +114,7 @@ HttpParser::HttpParser(Type type) {
     if ((self.m_valueBuf.size() + length) > self.m_maxLength) {
       return 1;
     }
-    self.m_valueBuf += StringRef{at, length};
+    self.m_valueBuf += std::string_view{at, length};
     return 0;
   };
 
@@ -154,7 +154,7 @@ HttpParser::HttpParser(Type type) {
   m_settings.on_body = [](http_parser* p, const char* at,
                           size_t length) -> int {
     auto& self = *static_cast<HttpParser*>(p->data);
-    self.body(StringRef{at, length}, self.IsBodyFinal());
+    self.body(std::string_view{at, length}, self.IsBodyFinal());
     return self.m_aborted;
   };
 
diff --git a/wpiutil/src/main/native/cpp/HttpServerConnection.cpp b/wpiutil/src/main/native/cpp/HttpServerConnection.cpp
index b7352abbcc..7ef52273e8 100644
--- a/wpiutil/src/main/native/cpp/HttpServerConnection.cpp
+++ b/wpiutil/src/main/native/cpp/HttpServerConnection.cpp
@@ -4,8 +4,11 @@
 
 #include "wpi/HttpServerConnection.h"
 
+#include "fmt/format.h"
 #include "wpi/SmallString.h"
 #include "wpi/SmallVector.h"
+#include "wpi/StringExtras.h"
+#include "wpi/fmt/raw_ostream.h"
 #include "wpi/raw_uv_ostream.h"
 
 using namespace wpi;
@@ -21,16 +24,18 @@ HttpServerConnection::HttpServerConnection(std::shared_ptr<uv::Stream> stream)
 
   // look for Accept-Encoding headers to determine if gzip is acceptable
   m_request.messageBegin.connect([this] { m_acceptGzip = false; });
-  m_request.header.connect([this](StringRef name, StringRef value) {
-    if (name.equals_lower("accept-encoding") && value.contains("gzip")) {
-      m_acceptGzip = true;
-    }
-  });
+  m_request.header.connect(
+      [this](std::string_view name, std::string_view value) {
+        if (wpi::equals_lower(name, "accept-encoding") &&
+            wpi::contains(value, "gzip")) {
+          m_acceptGzip = true;
+        }
+      });
 
   // pass incoming data to HTTP parser
   m_dataConn =
       stream->data.connect_connection([this](uv::Buffer& buf, size_t size) {
-        m_request.Execute(StringRef{buf.base, size});
+        m_request.Execute({buf.base, size});
         if (m_request.HasError()) {
           // could not parse; just close the connection
           m_stream.Close();
@@ -54,12 +59,12 @@ void HttpServerConnection::BuildCommonHeaders(raw_ostream& os) {
 }
 
 void HttpServerConnection::BuildHeader(raw_ostream& os, int code,
-                                       const Twine& codeText,
-                                       const Twine& contentType,
+                                       std::string_view codeText,
+                                       std::string_view contentType,
                                        uint64_t contentLength,
-                                       const Twine& extra) {
-  os << "HTTP/" << m_request.GetMajor() << '.' << m_request.GetMinor() << ' '
-     << code << ' ' << codeText << "\r\n";
+                                       std::string_view extra) {
+  fmt::print(os, "HTTP/{}.{} {} {}\r\n", m_request.GetMajor(),
+             m_request.GetMinor(), code, codeText);
   if (contentLength == 0) {
     m_keepAlive = false;
   }
@@ -69,13 +74,11 @@ void HttpServerConnection::BuildHeader(raw_ostream& os, int code,
   BuildCommonHeaders(os);
   os << "Content-Type: " << contentType << "\r\n";
   if (contentLength != 0) {
-    os << "Content-Length: " << contentLength << "\r\n";
+    fmt::print(os, "Content-Length: {}\r\n", contentLength);
   }
   os << "Access-Control-Allow-Origin: *\r\nAccess-Control-Allow-Methods: *\r\n";
-  SmallString<128> extraBuf;
-  StringRef extraStr = extra.toStringRef(extraBuf);
-  if (!extraStr.empty()) {
-    os << extraStr;
+  if (!extra.empty()) {
+    os << extra;
   }
   os << "\r\n";  // header ends with a blank line
 }
@@ -93,10 +96,10 @@ void HttpServerConnection::SendData(ArrayRef<uv::Buffer> bufs,
   });
 }
 
-void HttpServerConnection::SendResponse(int code, const Twine& codeText,
-                                        const Twine& contentType,
-                                        StringRef content,
-                                        const Twine& extraHeader) {
+void HttpServerConnection::SendResponse(int code, std::string_view codeText,
+                                        std::string_view contentType,
+                                        std::string_view content,
+                                        std::string_view extraHeader) {
   SmallVector<uv::Buffer, 4> toSend;
   raw_uv_ostream os{toSend, 4096};
   BuildHeader(os, code, codeText, contentType, content.size(), extraHeader);
@@ -105,13 +108,12 @@ void HttpServerConnection::SendResponse(int code, const Twine& codeText,
   SendData(os.bufs(), !m_keepAlive);
 }
 
-void HttpServerConnection::SendStaticResponse(int code, const Twine& codeText,
-                                              const Twine& contentType,
-                                              StringRef content, bool gzipped,
-                                              const Twine& extraHeader) {
+void HttpServerConnection::SendStaticResponse(
+    int code, std::string_view codeText, std::string_view contentType,
+    std::string_view content, bool gzipped, std::string_view extraHeader) {
   // TODO: handle remote side not accepting gzip (very rare)
 
-  StringRef contentEncodingHeader;
+  std::string_view contentEncodingHeader;
   if (gzipped /* && m_acceptGzip*/) {
     contentEncodingHeader = "Content-Encoding: gzip\r\n";
   }
@@ -119,7 +121,7 @@ void HttpServerConnection::SendStaticResponse(int code, const Twine& codeText,
   SmallVector<uv::Buffer, 4> bufs;
   raw_uv_ostream os{bufs, 4096};
   BuildHeader(os, code, codeText, contentType, content.size(),
-              extraHeader + contentEncodingHeader);
+              fmt::format("{}{}", extraHeader, contentEncodingHeader));
   // can send content without copying
   bufs.emplace_back(content);
 
@@ -135,8 +137,8 @@ void HttpServerConnection::SendStaticResponse(int code, const Twine& codeText,
   });
 }
 
-void HttpServerConnection::SendError(int code, const Twine& message) {
-  StringRef codeText, extra, baseMessage;
+void HttpServerConnection::SendError(int code, std::string_view message) {
+  std::string_view codeText, extra, baseMessage;
   switch (code) {
     case 401:
       codeText = "Unauthorized";
@@ -169,8 +171,8 @@ void HttpServerConnection::SendError(int code, const Twine& message) {
       baseMessage = "501: Not Implemented!";
       break;
   }
-  SmallString<256> content = baseMessage;
+  SmallString<256> content{baseMessage};
   content += "\r\n";
-  message.toVector(content);
-  SendResponse(code, codeText, "text/plain", content, extra);
+  content += message;
+  SendResponse(code, codeText, "text/plain", content.str(), extra);
 }
diff --git a/wpiutil/src/main/native/cpp/HttpUtil.cpp b/wpiutil/src/main/native/cpp/HttpUtil.cpp
index 086fdc87b7..802432e31e 100644
--- a/wpiutil/src/main/native/cpp/HttpUtil.cpp
+++ b/wpiutil/src/main/native/cpp/HttpUtil.cpp
@@ -6,6 +6,7 @@
 
 #include <cctype>
 
+#include "fmt/format.h"
 #include "wpi/Base64.h"
 #include "wpi/STLExtras.h"
 #include "wpi/StringExtras.h"
@@ -14,12 +15,10 @@
 
 namespace wpi {
 
-StringRef UnescapeURI(const Twine& str, SmallVectorImpl<char>& buf,
-                      bool* error) {
-  SmallString<128> strBuf;
-  StringRef strStr = str.toStringRef(strBuf);
+std::string_view UnescapeURI(std::string_view str, SmallVectorImpl<char>& buf,
+                             bool* error) {
   buf.clear();
-  for (auto i = strStr.begin(), end = strStr.end(); i != end; ++i) {
+  for (auto i = str.begin(), end = str.end(); i != end; ++i) {
     // pass non-escaped characters to output
     if (*i != '%') {
       // decode + to space
@@ -34,35 +33,33 @@ StringRef UnescapeURI(const Twine& str, SmallVectorImpl<char>& buf,
     // are there enough characters left?
     if (i + 2 >= end) {
       *error = true;
-      return StringRef{};
+      return {};
     }
 
     // replace %xx with the corresponding character
     unsigned val1 = hexDigitValue(*++i);
     if (val1 == -1U) {
       *error = true;
-      return StringRef{};
+      return {};
     }
     unsigned val2 = hexDigitValue(*++i);
     if (val2 == -1U) {
       *error = true;
-      return StringRef{};
+      return {};
     }
     buf.push_back((val1 << 4) | val2);
   }
 
   *error = false;
-  return StringRef{buf.data(), buf.size()};
+  return {buf.data(), buf.size()};
 }
 
-StringRef EscapeURI(const Twine& str, SmallVectorImpl<char>& buf,
-                    bool spacePlus) {
+std::string_view EscapeURI(std::string_view str, SmallVectorImpl<char>& buf,
+                           bool spacePlus) {
   static const char* const hexLut = "0123456789ABCDEF";
 
-  SmallString<128> strBuf;
-  StringRef strStr = str.toStringRef(strBuf);
   buf.clear();
-  for (auto i = strStr.begin(), end = strStr.end(); i != end; ++i) {
+  for (auto i = str.begin(), end = str.end(); i != end; ++i) {
     // pass unreserved characters to output
     if (std::isalnum(*i) || *i == '-' || *i == '_' || *i == '.' || *i == '~') {
       buf.push_back(*i);
@@ -81,15 +78,15 @@ StringRef EscapeURI(const Twine& str, SmallVectorImpl<char>& buf,
     buf.push_back(hexLut[(*i) & 0x0f]);
   }
 
-  return StringRef{buf.data(), buf.size()};
+  return {buf.data(), buf.size()};
 }
 
-HttpQueryMap::HttpQueryMap(wpi::StringRef query) {
-  wpi::SmallVector<wpi::StringRef, 16> queryElems;
-  query.split(queryElems, '&', 100, false);
+HttpQueryMap::HttpQueryMap(std::string_view query) {
+  SmallVector<std::string_view, 16> queryElems;
+  split(query, queryElems, '&', 100, false);
   for (auto elem : queryElems) {
-    auto [nameEsc, valueEsc] = elem.split('=');
-    wpi::SmallString<64> nameBuf;
+    auto [nameEsc, valueEsc] = split(elem, '=');
+    SmallString<64> nameBuf;
     bool err = false;
     auto name = wpi::UnescapeURI(nameEsc, nameBuf, &err);
     // note: ignores duplicates
@@ -99,8 +96,8 @@ HttpQueryMap::HttpQueryMap(wpi::StringRef query) {
   }
 }
 
-std::optional<wpi::StringRef> HttpQueryMap::Get(
-    wpi::StringRef name, wpi::SmallVectorImpl<char>& buf) const {
+std::optional<std::string_view> HttpQueryMap::Get(
+    std::string_view name, wpi::SmallVectorImpl<char>& buf) const {
   auto it = m_elems.find(name);
   if (it == m_elems.end()) {
     return {};
@@ -113,16 +110,16 @@ std::optional<wpi::StringRef> HttpQueryMap::Get(
   return val;
 }
 
-HttpPath::HttpPath(wpi::StringRef path) {
+HttpPath::HttpPath(std::string_view path) {
   // special-case root path to be a single empty element
   if (path == "/") {
     m_pathEnds.emplace_back(0);
     return;
   }
-  wpi::SmallVector<wpi::StringRef, 16> pathElems;
-  path.split(pathElems, '/', 100, false);
+  wpi::SmallVector<std::string_view, 16> pathElems;
+  split(path, pathElems, '/', 100, false);
   for (auto elem : pathElems) {
-    wpi::SmallString<64> buf;
+    SmallString<64> buf;
     bool err = false;
     auto val = wpi::UnescapeURI(elem, buf, &err);
     if (err) {
@@ -134,14 +131,15 @@ HttpPath::HttpPath(wpi::StringRef path) {
   }
 }
 
-bool HttpPath::startswith(size_t start, ArrayRef<StringRef> match) const {
+bool HttpPath::startswith(size_t start,
+                          ArrayRef<std::string_view> match) const {
   if (m_pathEnds.size() < (start + match.size())) {
     return false;
   }
   bool first = start == 0;
   auto p = m_pathEnds.begin() + start;
   for (auto m : match) {
-    auto val = m_pathBuf.slice(first ? 0 : *(p - 1), *p);
+    auto val = slice(m_pathBuf, first ? 0 : *(p - 1), *p);
     if (val != m) {
       return false;
     }
@@ -151,6 +149,10 @@ bool HttpPath::startswith(size_t start, ArrayRef<StringRef> match) const {
   return true;
 }
 
+std::string_view HttpPath::operator[](size_t n) const {
+  return slice(m_pathBuf, n == 0 ? 0 : m_pathEnds[n - 1], m_pathEnds[n]);
+}
+
 bool ParseHttpHeaders(raw_istream& is, SmallVectorImpl<char>* contentType,
                       SmallVectorImpl<char>* contentLength) {
   if (contentType) {
@@ -164,7 +166,7 @@ bool ParseHttpHeaders(raw_istream& is, SmallVectorImpl<char>* contentType,
   bool inContentLength = false;
   SmallString<64> lineBuf;
   for (;;) {
-    StringRef line = is.getline(lineBuf, 1024).rtrim();
+    std::string_view line = rtrim(is.getline(lineBuf, 1024));
     if (is.has_error()) {
       return false;
     }
@@ -176,12 +178,12 @@ bool ParseHttpHeaders(raw_istream& is, SmallVectorImpl<char>* contentType,
     if (!std::isspace(line[0])) {
       inContentType = false;
       inContentLength = false;
-      StringRef field;
-      std::tie(field, line) = line.split(':');
-      field = field.rtrim();
-      if (field.equals_lower("content-type")) {
+      std::string_view field;
+      std::tie(field, line) = split(line, ':');
+      field = rtrim(field);
+      if (equals_lower(field, "content-type")) {
         inContentType = true;
-      } else if (field.equals_lower("content-length")) {
+      } else if (equals_lower(field, "content-length")) {
         inContentLength = true;
       } else {
         continue;  // ignore other fields
@@ -189,7 +191,7 @@ bool ParseHttpHeaders(raw_istream& is, SmallVectorImpl<char>* contentType,
     }
 
     // collapse whitespace
-    line = line.ltrim();
+    line = ltrim(line);
 
     // save field data
     if (inContentType && contentType) {
@@ -200,7 +202,7 @@ bool ParseHttpHeaders(raw_istream& is, SmallVectorImpl<char>* contentType,
   }
 }
 
-bool FindMultipartBoundary(raw_istream& is, StringRef boundary,
+bool FindMultipartBoundary(raw_istream& is, std::string_view boundary,
                            std::string* saveBuf) {
   SmallString<64> searchBuf;
   searchBuf.resize(boundary.size() + 2);
@@ -237,7 +239,7 @@ bool FindMultipartBoundary(raw_istream& is, StringRef boundary,
 
     // Fast-scan for '-'
     size_t pos = searchBuf.find('-', searchBuf[0] == '-' ? 1 : 0);
-    if (pos == StringRef::npos) {
+    if (pos == std::string_view::npos) {
       if (saveBuf) {
         saveBuf->append(searchBuf.data(), searchBuf.size());
       }
@@ -254,63 +256,58 @@ bool FindMultipartBoundary(raw_istream& is, StringRef boundary,
   }
 }
 
-HttpLocation::HttpLocation(const Twine& url_, bool* error,
+HttpLocation::HttpLocation(std::string_view url_, bool* error,
                            std::string* errorMsg)
-    : url{url_.str()} {
+    : url{url_} {
   // Split apart into components
-  StringRef query{url};
+  std::string_view query{url};
 
   // scheme:
-  StringRef scheme;
-  std::tie(scheme, query) = query.split(':');
-  if (!scheme.equals_lower("http")) {
+  std::string_view scheme;
+  std::tie(scheme, query) = split(query, ':');
+  if (!equals_lower(scheme, "http")) {
     *errorMsg = "only supports http URLs";
     *error = true;
     return;
   }
 
   // "//"
-  if (!query.startswith("//")) {
+  if (!starts_with(query, "//")) {
     *errorMsg = "expected http://...";
     *error = true;
     return;
   }
-  query = query.drop_front(2);
+  query.remove_prefix(2);
 
   // user:password@host:port/
-  StringRef authority;
-  std::tie(authority, query) = query.split('/');
+  std::string_view authority;
+  std::tie(authority, query) = split(query, '/');
 
-  StringRef userpass, hostport;
-  std::tie(userpass, hostport) = authority.split('@');
+  auto [userpass, hostport] = split(authority, '@');
   // split leaves the RHS empty if the split char isn't present...
   if (hostport.empty()) {
     hostport = userpass;
-    userpass = StringRef{};
+    userpass = {};
   }
 
   if (!userpass.empty()) {
-    StringRef rawUser, rawPassword;
-    std::tie(rawUser, rawPassword) = userpass.split(':');
+    auto [rawUser, rawPassword] = split(userpass, ':');
     SmallString<64> userBuf, passBuf;
     user = UnescapeURI(rawUser, userBuf, error);
     if (*error) {
-      raw_string_ostream oss(*errorMsg);
-      oss << "could not unescape user \"" << rawUser << "\"";
-      oss.flush();
+      *errorMsg = fmt::format("could not unescape user \"{}\"", rawUser);
       return;
     }
     password = UnescapeURI(rawPassword, passBuf, error);
     if (*error) {
-      raw_string_ostream oss(*errorMsg);
-      oss << "could not unescape password \"" << rawPassword << "\"";
-      oss.flush();
+      *errorMsg =
+          fmt::format("could not unescape password \"{}\"", rawPassword);
       return;
     }
   }
 
-  StringRef portStr;
-  std::tie(host, portStr) = hostport.rsplit(':');
+  std::string_view portStr;
+  std::tie(host, portStr) = rsplit(hostport, ':');
   if (host.empty()) {
     *errorMsg = "host is empty";
     *error = true;
@@ -318,46 +315,42 @@ HttpLocation::HttpLocation(const Twine& url_, bool* error,
   }
   if (portStr.empty()) {
     port = 80;
-  } else if (portStr.getAsInteger(10, port)) {
-    raw_string_ostream oss(*errorMsg);
-    oss << "port \"" << portStr << "\" is not an integer";
-    oss.flush();
+  } else if (auto p = parse_integer<int>(portStr, 10)) {
+    port = p.value();
+  } else {
+    *errorMsg = fmt::format("port \"{}\" is not an integer", portStr);
     *error = true;
     return;
   }
 
   // path?query#fragment
-  std::tie(query, fragment) = query.split('#');
-  std::tie(path, query) = query.split('?');
+  std::tie(query, fragment) = split(query, '#');
+  std::tie(path, query) = split(query, '?');
 
   // Split query string into parameters
   while (!query.empty()) {
     // split out next param and value
-    StringRef rawParam, rawValue;
-    std::tie(rawParam, query) = query.split('&');
+    std::string_view rawParam, rawValue;
+    std::tie(rawParam, query) = split(query, '&');
     if (rawParam.empty()) {
       continue;  // ignore "&&"
     }
-    std::tie(rawParam, rawValue) = rawParam.split('=');
+    std::tie(rawParam, rawValue) = split(rawParam, '=');
 
     // unescape param
     *error = false;
     SmallString<64> paramBuf;
-    StringRef param = UnescapeURI(rawParam, paramBuf, error);
+    std::string_view param = UnescapeURI(rawParam, paramBuf, error);
     if (*error) {
-      raw_string_ostream oss(*errorMsg);
-      oss << "could not unescape parameter \"" << rawParam << "\"";
-      oss.flush();
+      *errorMsg = fmt::format("could not unescape parameter \"{}\"", rawParam);
       return;
     }
 
     // unescape value
     SmallString<64> valueBuf;
-    StringRef value = UnescapeURI(rawValue, valueBuf, error);
+    std::string_view value = UnescapeURI(rawValue, valueBuf, error);
     if (*error) {
-      raw_string_ostream oss(*errorMsg);
-      oss << "could not unescape value \"" << rawValue << "\"";
-      oss.flush();
+      *errorMsg = fmt::format("could not unescape value \"{}\"", rawValue);
       return;
     }
 
@@ -373,7 +366,7 @@ void HttpRequest::SetAuth(const HttpLocation& loc) {
     userpass += loc.user;
     userpass += ':';
     userpass += loc.password;
-    Base64Encode(userpass, &auth);
+    Base64Encode(userpass.str(), &auth);
   }
 }
 
@@ -390,24 +383,22 @@ bool HttpConnection::Handshake(const HttpRequest& request,
 
   // read first line of response
   SmallString<64> lineBuf;
-  StringRef line = is.getline(lineBuf, 1024).rtrim();
+  std::string_view line = rtrim(is.getline(lineBuf, 1024));
   if (is.has_error()) {
     *warnMsg = "disconnected before response";
     return false;
   }
 
   // see if we got a HTTP 200 response
-  StringRef httpver, code, codeText;
-  std::tie(httpver, line) = line.split(' ');
-  std::tie(code, codeText) = line.split(' ');
-  if (!httpver.startswith("HTTP")) {
+  std::string_view httpver, code, codeText;
+  std::tie(httpver, line) = split(line, ' ');
+  std::tie(code, codeText) = split(line, ' ');
+  if (!starts_with(httpver, "HTTP")) {
     *warnMsg = "did not receive HTTP response";
     return false;
   }
   if (code != "200") {
-    raw_string_ostream oss(*warnMsg);
-    oss << "received " << code << " " << codeText << " response";
-    oss.flush();
+    *warnMsg = fmt::format("received {} {} response", code, codeText);
     return false;
   }
 
@@ -420,7 +411,7 @@ bool HttpConnection::Handshake(const HttpRequest& request,
   return true;
 }
 
-void HttpMultipartScanner::SetBoundary(StringRef boundary) {
+void HttpMultipartScanner::SetBoundary(std::string_view boundary) {
   m_boundaryWith = "\n--";
   m_boundaryWith += boundary;
   m_boundaryWithout = "\n";
@@ -436,7 +427,7 @@ void HttpMultipartScanner::Reset(bool saveSkipped) {
   m_buf.resize(0);
 }
 
-StringRef HttpMultipartScanner::Execute(StringRef in) {
+std::string_view HttpMultipartScanner::Execute(std::string_view in) {
   if (m_state == kDone) {
     Reset(m_saveSkipped);
   }
@@ -483,7 +474,7 @@ StringRef HttpMultipartScanner::Execute(StringRef in) {
   }
 
   if (m_state == kPadding) {
-    for (char ch : in.drop_front(pos)) {
+    for (char ch : drop_front(in, pos)) {
       ++pos;
       if (ch == '\n') {
         // Found the LF; return remaining input buffer (following it)
@@ -491,13 +482,13 @@ StringRef HttpMultipartScanner::Execute(StringRef in) {
         if (m_saveSkipped) {
           m_buf.resize(m_buf.size() - in.size() + pos);
         }
-        return in.drop_front(pos);
+        return drop_front(in, pos);
       }
     }
   }
 
   // We consumed the entire input
-  return StringRef{};
+  return {};
 }
 
 }  // namespace wpi
diff --git a/wpiutil/src/main/native/cpp/Logger.cpp b/wpiutil/src/main/native/cpp/Logger.cpp
new file mode 100644
index 0000000000..629c14a60d
--- /dev/null
+++ b/wpiutil/src/main/native/cpp/Logger.cpp
@@ -0,0 +1,26 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include "wpi/Logger.h"
+
+using namespace wpi;
+
+void Logger::DoLog(unsigned int level, const char* file, unsigned int line,
+                   const char* msg) {
+  if (!m_func || level < m_min_level) {
+    return;
+  }
+  m_func(level, file, line, msg);
+}
+
+void Logger::LogV(unsigned int level, const char* file, unsigned int line,
+                  fmt::string_view format, fmt::format_args args) {
+  if (!m_func || level < m_min_level) {
+    return;
+  }
+  fmt::memory_buffer out;
+  fmt::vformat_to(out, format, args);
+  out.push_back('\0');
+  m_func(level, file, line, out.data());
+}
diff --git a/wpiutil/src/main/native/cpp/MimeTypes.cpp b/wpiutil/src/main/native/cpp/MimeTypes.cpp
index 664122a408..082dab140c 100644
--- a/wpiutil/src/main/native/cpp/MimeTypes.cpp
+++ b/wpiutil/src/main/native/cpp/MimeTypes.cpp
@@ -10,7 +10,7 @@ namespace wpi {
 
 // derived partially from
 // https://github.com/DEGoodmanWilson/libmime/blob/stable/0.1.2/mime/mime.cpp
-StringRef MimeTypeFromPath(StringRef path) {
+std::string_view MimeTypeFromPath(std::string_view path) {
   // https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types
   static StringMap<const char*> mimeTypes{
       // text
@@ -52,11 +52,11 @@ StringRef MimeTypeFromPath(StringRef path) {
   static const char* defaultType = "application/octet-stream";
 
   auto pos = path.find_last_of("/");
-  if (pos != StringRef::npos) {
+  if (pos != std::string_view::npos) {
     path = path.substr(pos + 1);
   }
   auto dot_pos = path.find_last_of(".");
-  if (dot_pos > 0 && dot_pos != StringRef::npos) {
+  if (dot_pos > 0 && dot_pos != std::string_view::npos) {
     auto type = mimeTypes.find(path.substr(dot_pos + 1));
     if (type != mimeTypes.end()) {
       return type->getValue();
diff --git a/wpiutil/src/main/native/cpp/PortForwarder.cpp b/wpiutil/src/main/native/cpp/PortForwarder.cpp
index d2b80b14a9..797c7c7fdb 100644
--- a/wpiutil/src/main/native/cpp/PortForwarder.cpp
+++ b/wpiutil/src/main/native/cpp/PortForwarder.cpp
@@ -4,10 +4,9 @@
 
 #include "wpi/PortForwarder.h"
 
+#include "fmt/format.h"
 #include "wpi/DenseMap.h"
 #include "wpi/EventLoopRunner.h"
-#include "wpi/SmallString.h"
-#include "wpi/raw_ostream.h"
 #include "wpi/uv/GetAddrInfo.h"
 #include "wpi/uv/Tcp.h"
 #include "wpi/uv/Timer.h"
@@ -45,7 +44,7 @@ static void CopyStream(uv::Stream& in, std::weak_ptr<uv::Stream> outWeak) {
   });
 }
 
-void PortForwarder::Add(unsigned int port, const Twine& remoteHost,
+void PortForwarder::Add(unsigned int port, std::string_view remoteHost,
                         unsigned int remotePort) {
   m_impl->runner.ExecSync([&](uv::Loop& loop) {
     auto server = uv::Tcp::Create(loop);
@@ -55,7 +54,7 @@ void PortForwarder::Add(unsigned int port, const Twine& remoteHost,
 
     // when we get a connection, accept it
     server->connection.connect([serverPtr = server.get(),
-                                host = remoteHost.str(), remotePort] {
+                                host = std::string{remoteHost}, remotePort] {
       auto& loop = serverPtr->GetLoopRef();
       auto client = serverPtr->Accept();
       if (!client) {
@@ -80,10 +79,6 @@ void PortForwarder::Add(unsigned int port, const Twine& remoteHost,
             }
           });
 
-      // convert port to string
-      SmallString<16> remotePortStr;
-      raw_svector_ostream(remotePortStr) << remotePort;
-
       // resolve address
       uv::GetAddrInfo(
           loop,
@@ -125,7 +120,7 @@ void PortForwarder::Add(unsigned int port, const Twine& remoteHost,
               CopyStream(*remotePtr, clientWeak);
             });
           },
-          host, remotePortStr);
+          host, fmt::to_string(remotePort));
 
       // time out for connection
       uv::Timer::SingleShot(loop, uv::Timer::Time{500},
diff --git a/wpiutil/src/main/native/cpp/StringExtras.cpp b/wpiutil/src/main/native/cpp/StringExtras.cpp
index 2fbf21346a..45d23ea1b7 100644
--- a/wpiutil/src/main/native/cpp/StringExtras.cpp
+++ b/wpiutil/src/main/native/cpp/StringExtras.cpp
@@ -23,7 +23,6 @@
 
 #include "wpi/SmallString.h"
 #include "wpi/SmallVector.h"
-#include "wpi/StringRef.h"
 
 // strncasecmp() is not available on non-POSIX systems, so define an
 // alternative function here.
@@ -178,34 +177,143 @@ void wpi::split(std::string_view str, SmallVectorImpl<std::string_view>& arr,
   }
 }
 
-bool wpi::detail::GetAsUnsignedInteger(
-    std::string_view str, unsigned radix,
-    unsigned long long& result) noexcept {  // NOLINT(runtime/int)
-  return wpi::getAsUnsignedInteger(str, radix, result);
-}
+static unsigned GetAutoSenseRadix(std::string_view& str) noexcept {
+  if (str.empty()) {
+    return 10;
+  }
 
-bool wpi::detail::GetAsSignedInteger(
-    std::string_view str, unsigned radix,
-    long long& result) noexcept {  // NOLINT(runtime/int)
-  return wpi::getAsSignedInteger(str, radix, result);
+  if (wpi::starts_with(str, "0x") || wpi::starts_with(str, "0X")) {
+    str.remove_prefix(2);
+    return 16;
+  }
+
+  if (wpi::starts_with(str, "0b") || wpi::starts_with(str, "0B")) {
+    str.remove_prefix(2);
+    return 2;
+  }
+
+  if (wpi::starts_with(str, "0o")) {
+    str.remove_prefix(2);
+    return 8;
+  }
+
+  if (str[0] == '0' && str.size() > 1 && wpi::isDigit(str[1])) {
+    str.remove_prefix(1);
+    return 8;
+  }
+
+  return 10;
 }
 
 bool wpi::detail::ConsumeUnsignedInteger(
     std::string_view& str, unsigned radix,
     unsigned long long& result) noexcept {  // NOLINT(runtime/int)
-  wpi::StringRef sref = str;
-  bool rv = wpi::consumeUnsignedInteger(sref, radix, result);
-  str = sref;
-  return rv;
+  // Autosense radix if not specified.
+  if (radix == 0) {
+    radix = GetAutoSenseRadix(str);
+  }
+
+  // Empty strings (after the radix autosense) are invalid.
+  if (str.empty()) {
+    return true;
+  }
+
+  // Parse all the bytes of the string given this radix.  Watch for overflow.
+  std::string_view str2 = str;
+  result = 0;
+  while (!str2.empty()) {
+    unsigned charVal;
+    if (str2[0] >= '0' && str2[0] <= '9') {
+      charVal = str2[0] - '0';
+    } else if (str2[0] >= 'a' && str2[0] <= 'z') {
+      charVal = str2[0] - 'a' + 10;
+    } else if (str2[0] >= 'A' && str2[0] <= 'Z') {
+      charVal = str2[0] - 'A' + 10;
+    } else {
+      break;
+    }
+
+    // If the parsed value is larger than the integer radix, we cannot
+    // consume any more characters.
+    if (charVal >= radix) {
+      break;
+    }
+
+    // Add in this character.
+    unsigned long long prevResult = result;  // NOLINT(runtime/int)
+    result = result * radix + charVal;
+
+    // Check for overflow by shifting back and seeing if bits were lost.
+    if (result / radix < prevResult) {
+      return true;
+    }
+
+    str2.remove_prefix(1);
+  }
+
+  // We consider the operation a failure if no characters were consumed
+  // successfully.
+  if (str.size() == str2.size()) {
+    return true;
+  }
+
+  str = str2;
+  return false;
 }
 
 bool wpi::detail::ConsumeSignedInteger(
     std::string_view& str, unsigned radix,
     long long& result) noexcept {  // NOLINT(runtime/int)
-  wpi::StringRef sref = str;
-  bool rv = wpi::consumeSignedInteger(sref, radix, result);
-  str = sref;
-  return rv;
+  unsigned long long ullVal;       // NOLINT(runtime/int)
+
+  // Handle positive strings first.
+  if (str.empty() || str.front() != '-') {
+    if (wpi::detail::ConsumeUnsignedInteger(str, radix, ullVal) ||
+        // Check for value so large it overflows a signed value.
+        static_cast<long long>(ullVal) < 0) {  // NOLINT(runtime/int)
+      return true;
+    }
+    result = ullVal;
+    return false;
+  }
+
+  // Get the positive part of the value.
+  std::string_view str2 = wpi::drop_front(str, 1);
+  if (wpi::detail::ConsumeUnsignedInteger(str2, radix, ullVal) ||
+      // Reject values so large they'd overflow as negative signed, but allow
+      // "-0".  This negates the unsigned so that the negative isn't undefined
+      // on signed overflow.
+      static_cast<long long>(-ullVal) > 0) {  // NOLINT(runtime/int)
+    return true;
+  }
+
+  str = str2;
+  result = -ullVal;
+  return false;
+}
+
+bool wpi::detail::GetAsUnsignedInteger(
+    std::string_view str, unsigned radix,
+    unsigned long long& result) noexcept {  // NOLINT(runtime/int)
+  if (wpi::detail::ConsumeUnsignedInteger(str, radix, result)) {
+    return true;
+  }
+
+  // For getAsUnsignedInteger, we require the whole string to be consumed or
+  // else we consider it a failure.
+  return !str.empty();
+}
+
+bool wpi::detail::GetAsSignedInteger(
+    std::string_view str, unsigned radix,
+    long long& result) noexcept {  // NOLINT(runtime/int)
+  if (wpi::detail::ConsumeSignedInteger(str, radix, result)) {
+    return true;
+  }
+
+  // For getAsSignedInteger, we require the whole string to be consumed or else
+  // we consider it a failure.
+  return !str.empty();
 }
 
 template <>
diff --git a/wpiutil/src/main/native/cpp/TCPAcceptor.cpp b/wpiutil/src/main/native/cpp/TCPAcceptor.cpp
index de4bfcf1d7..8d12ac3a12 100644
--- a/wpiutil/src/main/native/cpp/TCPAcceptor.cpp
+++ b/wpiutil/src/main/native/cpp/TCPAcceptor.cpp
@@ -44,7 +44,7 @@
 
 using namespace wpi;
 
-TCPAcceptor::TCPAcceptor(int port, const char* address, Logger& logger)
+TCPAcceptor::TCPAcceptor(int port, std::string_view address, Logger& logger)
     : m_lsd(0),
       m_port(port),
       m_address(address),
@@ -79,7 +79,7 @@ int TCPAcceptor::start() {
 
   m_lsd = socket(PF_INET, SOCK_STREAM, 0);
   if (m_lsd < 0) {
-    WPI_ERROR(m_logger, "could not create socket");
+    WPI_ERROR(m_logger, "{}", "could not create socket");
     return -1;
   }
   struct sockaddr_in address;
@@ -95,7 +95,7 @@ int TCPAcceptor::start() {
     int res = inet_pton(PF_INET, m_address.c_str(), &(address.sin_addr));
 #endif
     if (res != 1) {
-      WPI_ERROR(m_logger, "could not resolve " << m_address << " address");
+      WPI_ERROR(m_logger, "could not resolve {} address", m_address);
       return -1;
     }
   } else {
@@ -116,15 +116,15 @@ int TCPAcceptor::start() {
   int result = bind(m_lsd, reinterpret_cast<struct sockaddr*>(&address),
                     sizeof(address));
   if (result != 0) {
-    WPI_ERROR(m_logger,
-              "bind() to port " << m_port << " failed: " << SocketStrerror());
+    WPI_ERROR(m_logger, "bind() to port {} failed: {}", m_port,
+              SocketStrerror());
     return result;
   }
 
   result = listen(m_lsd, 5);
   if (result != 0) {
-    WPI_ERROR(m_logger,
-              "listen() on port " << m_port << " failed: " << SocketStrerror());
+    WPI_ERROR(m_logger, "listen() on port {} failed: {}", m_port,
+              SocketStrerror());
     return result;
   }
   m_listening = true;
@@ -193,8 +193,8 @@ std::unique_ptr<NetworkStream> TCPAcceptor::accept() {
   int sd = ::accept(m_lsd, reinterpret_cast<struct sockaddr*>(&address), &len);
   if (sd < 0) {
     if (!m_shutdown) {
-      WPI_ERROR(m_logger, "accept() on port "
-                              << m_port << " failed: " << SocketStrerror());
+      WPI_ERROR(m_logger, "accept() on port {} failed: {}", m_port,
+                SocketStrerror());
     }
     return nullptr;
   }
diff --git a/wpiutil/src/main/native/cpp/TCPConnector.cpp b/wpiutil/src/main/native/cpp/TCPConnector.cpp
index 20fdbc9369..ed97962463 100644
--- a/wpiutil/src/main/native/cpp/TCPConnector.cpp
+++ b/wpiutil/src/main/native/cpp/TCPConnector.cpp
@@ -96,7 +96,7 @@ std::unique_ptr<NetworkStream> TCPConnector::connect(const char* server,
     int res = inet_pton(PF_INET, server, &(address.sin_addr));
 #endif
     if (res != 1) {
-      WPI_ERROR(logger, "could not resolve " << server << " address");
+      WPI_ERROR(logger, "could not resolve {} address", server);
       return nullptr;
     }
   }
@@ -105,13 +105,13 @@ std::unique_ptr<NetworkStream> TCPConnector::connect(const char* server,
   if (timeout == 0) {
     int sd = socket(AF_INET, SOCK_STREAM, 0);
     if (sd < 0) {
-      WPI_ERROR(logger, "could not create socket");
+      WPI_ERROR(logger, "{}", "could not create socket");
       return nullptr;
     }
     if (::connect(sd, reinterpret_cast<struct sockaddr*>(&address),
                   sizeof(address)) != 0) {
-      WPI_ERROR(logger, "connect() to " << server << " port " << port
-                                        << " failed: " << SocketStrerror());
+      WPI_ERROR(logger, "connect() to {} port {} failed: {}", server, port,
+                SocketStrerror());
 #ifdef _WIN32
       closesocket(sd);
 #else
@@ -127,7 +127,7 @@ std::unique_ptr<NetworkStream> TCPConnector::connect(const char* server,
   socklen_t len;
   int result = -1, valopt, sd = socket(AF_INET, SOCK_STREAM, 0);
   if (sd < 0) {
-    WPI_ERROR(logger, "could not create socket");
+    WPI_ERROR(logger, "{}", "could not create socket");
     return nullptr;
   }
 
@@ -135,19 +135,19 @@ std::unique_ptr<NetworkStream> TCPConnector::connect(const char* server,
 #ifdef _WIN32
   u_long mode = 1;
   if (ioctlsocket(sd, FIONBIO, &mode) == SOCKET_ERROR)
-    WPI_WARNING(logger,
-                "could not set socket to non-blocking: " << SocketStrerror());
+    WPI_WARNING(logger, "could not set socket to non-blocking: {}",
+                SocketStrerror());
 #else
   int arg;
   arg = fcntl(sd, F_GETFL, nullptr);
   if (arg < 0) {
-    WPI_WARNING(logger,
-                "could not set socket to non-blocking: " << SocketStrerror());
+    WPI_WARNING(logger, "could not set socket to non-blocking: {}",
+                SocketStrerror());
   } else {
     arg |= O_NONBLOCK;
     if (fcntl(sd, F_SETFL, arg) < 0) {
-      WPI_WARNING(logger,
-                  "could not set socket to non-blocking: " << SocketStrerror());
+      WPI_WARNING(logger, "could not set socket to non-blocking: {}",
+                  SocketStrerror());
     }
   }
 #endif
@@ -170,21 +170,18 @@ std::unique_ptr<NetworkStream> TCPConnector::connect(const char* server,
         getsockopt(sd, SOL_SOCKET, SO_ERROR, reinterpret_cast<char*>(&valopt),
                    &len);
         if (valopt) {
-          WPI_ERROR(logger, "select() to " << server << " port " << port
-                                           << " error " << valopt << " - "
-                                           << SocketStrerror(valopt));
+          WPI_ERROR(logger, "select() to {} port {} error {} - {}", server,
+                    port, valopt, SocketStrerror(valopt));
         } else {
           // connection established
           result = 0;
         }
       } else {
-        WPI_INFO(logger,
-                 "connect() to " << server << " port " << port << " timed out");
+        WPI_INFO(logger, "connect() to {} port {} timed out", server, port);
       }
     } else {
-      WPI_ERROR(logger, "connect() to " << server << " port " << port
-                                        << " error " << SocketErrno() << " - "
-                                        << SocketStrerror());
+      WPI_ERROR(logger, "connect() to {} port {} error {} - {}", server, port,
+                SocketErrno(), SocketStrerror());
     }
   }
 
@@ -192,18 +189,18 @@ std::unique_ptr<NetworkStream> TCPConnector::connect(const char* server,
 #ifdef _WIN32
   mode = 0;
   if (ioctlsocket(sd, FIONBIO, &mode) == SOCKET_ERROR)
-    WPI_WARNING(logger,
-                "could not set socket to blocking: " << SocketStrerror());
+    WPI_WARNING(logger, "could not set socket to blocking: {}",
+                SocketStrerror());
 #else
   arg = fcntl(sd, F_GETFL, nullptr);
   if (arg < 0) {
-    WPI_WARNING(logger,
-                "could not set socket to blocking: " << SocketStrerror());
+    WPI_WARNING(logger, "could not set socket to blocking: {}",
+                SocketStrerror());
   } else {
     arg &= (~O_NONBLOCK);
     if (fcntl(sd, F_SETFL, arg) < 0) {
-      WPI_WARNING(logger,
-                  "could not set socket to blocking: " << SocketStrerror());
+      WPI_WARNING(logger, "could not set socket to blocking: {}",
+                  SocketStrerror());
     }
   }
 #endif
diff --git a/wpiutil/src/main/native/cpp/TCPStream.cpp b/wpiutil/src/main/native/cpp/TCPStream.cpp
index 7a0ead1dac..45671611d4 100644
--- a/wpiutil/src/main/native/cpp/TCPStream.cpp
+++ b/wpiutil/src/main/native/cpp/TCPStream.cpp
@@ -168,7 +168,7 @@ void TCPStream::close() {
   m_sd = -1;
 }
 
-StringRef TCPStream::getPeerIP() const {
+std::string_view TCPStream::getPeerIP() const {
   return m_peerIP;
 }
 
diff --git a/wpiutil/src/main/native/cpp/UDPClient.cpp b/wpiutil/src/main/native/cpp/UDPClient.cpp
index afaad9fec9..3e90d47dca 100644
--- a/wpiutil/src/main/native/cpp/UDPClient.cpp
+++ b/wpiutil/src/main/native/cpp/UDPClient.cpp
@@ -16,14 +16,15 @@
 #endif
 
 #include "wpi/Logger.h"
+#include "wpi/SmallString.h"
 #include "wpi/SocketError.h"
 
 using namespace wpi;
 
 UDPClient::UDPClient(Logger& logger) : UDPClient("", logger) {}
 
-UDPClient::UDPClient(const Twine& address, Logger& logger)
-    : m_lsd(0), m_port(0), m_address(address.str()), m_logger(logger) {}
+UDPClient::UDPClient(std::string_view address, Logger& logger)
+    : m_lsd(0), m_port(0), m_address(address), m_logger(logger) {}
 
 UDPClient::UDPClient(UDPClient&& other)
     : m_lsd(other.m_lsd),
@@ -72,7 +73,7 @@ int UDPClient::start(int port) {
   m_lsd = socket(AF_INET, SOCK_DGRAM, 0);
 
   if (m_lsd < 0) {
-    WPI_ERROR(m_logger, "could not create socket");
+    WPI_ERROR(m_logger, "{}", "could not create socket");
     return -1;
   }
 
@@ -88,7 +89,7 @@ int UDPClient::start(int port) {
     int res = inet_pton(PF_INET, m_address.c_str(), &(addr.sin_addr));
 #endif
     if (res != 1) {
-      WPI_ERROR(m_logger, "could not resolve " << m_address << " address");
+      WPI_ERROR(m_logger, "could not resolve {} address", m_address);
       return -1;
     }
   } else {
@@ -110,7 +111,7 @@ int UDPClient::start(int port) {
 
   int result = bind(m_lsd, reinterpret_cast<sockaddr*>(&addr), sizeof(addr));
   if (result != 0) {
-    WPI_ERROR(m_logger, "bind() failed: " << SocketStrerror());
+    WPI_ERROR(m_logger, "bind() failed: {}", SocketStrerror());
     return result;
   }
   m_port = port;
@@ -132,25 +133,24 @@ void UDPClient::shutdown() {
   }
 }
 
-int UDPClient::send(ArrayRef<uint8_t> data, const Twine& server, int port) {
+int UDPClient::send(ArrayRef<uint8_t> data, std::string_view server, int port) {
   // server must be a resolvable IP address
   struct sockaddr_in addr;
   std::memset(&addr, 0, sizeof(addr));
   addr.sin_family = AF_INET;
-  SmallVector<char, 128> addr_store;
-  StringRef remoteAddr = server.toNullTerminatedStringRef(addr_store);
+  SmallString<128> remoteAddr{server};
   if (remoteAddr.empty()) {
-    WPI_ERROR(m_logger, "server must be passed");
+    WPI_ERROR(m_logger, "{}", "server must be passed");
     return -1;
   }
 
 #ifdef _WIN32
-  int res = InetPton(AF_INET, remoteAddr.data(), &(addr.sin_addr));
+  int res = InetPton(AF_INET, remoteAddr.c_str(), &(addr.sin_addr));
 #else
-  int res = inet_pton(AF_INET, remoteAddr.data(), &(addr.sin_addr));
+  int res = inet_pton(AF_INET, remoteAddr.c_str(), &(addr.sin_addr));
 #endif
   if (res != 1) {
-    WPI_ERROR(m_logger, "could not resolve " << server << " address");
+    WPI_ERROR(m_logger, "could not resolve {} address", server);
     return -1;
   }
   addr.sin_port = htons(port);
@@ -162,25 +162,24 @@ int UDPClient::send(ArrayRef<uint8_t> data, const Twine& server, int port) {
   return result;
 }
 
-int UDPClient::send(StringRef data, const Twine& server, int port) {
+int UDPClient::send(std::string_view data, std::string_view server, int port) {
   // server must be a resolvable IP address
   struct sockaddr_in addr;
   std::memset(&addr, 0, sizeof(addr));
   addr.sin_family = AF_INET;
-  SmallVector<char, 128> addr_store;
-  StringRef remoteAddr = server.toNullTerminatedStringRef(addr_store);
+  SmallString<128> remoteAddr{server};
   if (remoteAddr.empty()) {
-    WPI_ERROR(m_logger, "server must be passed");
+    WPI_ERROR(m_logger, "{}", "server must be passed");
     return -1;
   }
 
 #ifdef _WIN32
-  int res = InetPton(AF_INET, remoteAddr.data(), &(addr.sin_addr));
+  int res = InetPton(AF_INET, remoteAddr.c_str(), &(addr.sin_addr));
 #else
-  int res = inet_pton(AF_INET, remoteAddr.data(), &(addr.sin_addr));
+  int res = inet_pton(AF_INET, remoteAddr.c_str(), &(addr.sin_addr));
 #endif
   if (res != 1) {
-    WPI_ERROR(m_logger, "could not resolve " << server << " address");
+    WPI_ERROR(m_logger, "could not resolve {} address", server);
     return -1;
   }
   addr.sin_port = htons(port);
@@ -242,7 +241,7 @@ int UDPClient::set_timeout(double timeout) {
   int ret = setsockopt(m_lsd, SOL_SOCKET, SO_RCVTIMEO,
                        reinterpret_cast<char*>(&tv), sizeof(tv));
   if (ret < 0) {
-    WPI_ERROR(m_logger, "set timeout failed");
+    WPI_ERROR(m_logger, "{}", "set timeout failed");
   }
   return ret;
 }
diff --git a/wpiutil/src/main/native/cpp/WebSocket.cpp b/wpiutil/src/main/native/cpp/WebSocket.cpp
index 11e3391687..e7a38736c7 100644
--- a/wpiutil/src/main/native/cpp/WebSocket.cpp
+++ b/wpiutil/src/main/native/cpp/WebSocket.cpp
@@ -6,10 +6,12 @@
 
 #include <random>
 
+#include "fmt/format.h"
 #include "wpi/Base64.h"
 #include "wpi/HttpParser.h"
 #include "wpi/SmallString.h"
 #include "wpi/SmallVector.h"
+#include "wpi/StringExtras.h"
 #include "wpi/raw_uv_ostream.h"
 #include "wpi/sha1.h"
 #include "wpi/uv/Stream.h"
@@ -47,7 +49,7 @@ class WebSocket::ClientHandshakeData {
       v = static_cast<char>(dist(gen));
     }
     raw_svector_ostream os(key);
-    Base64Encode(os, StringRef{nonce, 16});
+    Base64Encode(os, {nonce, 16});
   }
   ~ClientHandshakeData() {
     if (auto t = timer.lock()) {
@@ -67,7 +69,8 @@ class WebSocket::ClientHandshakeData {
   std::weak_ptr<uv::Timer> timer;
 };
 
-static StringRef AcceptHash(StringRef key, SmallVectorImpl<char>& buf) {
+static std::string_view AcceptHash(std::string_view key,
+                                   SmallVectorImpl<char>& buf) {
   SHA1 hash;
   hash.Update(key);
   hash.Update("258EAFA5-E914-47DA-95CA-C5AB0DC85B11");
@@ -80,7 +83,7 @@ WebSocket::WebSocket(uv::Stream& stream, bool server, const private_init&)
   // Connect closed and error signals to ourselves
   m_stream.closed.connect([this]() { SetClosed(1006, "handle closed"); });
   m_stream.error.connect([this](uv::Error err) {
-    Terminate(1006, "stream error: " + Twine(err.name()));
+    Terminate(1006, fmt::format("stream error: {}", err.name()));
   });
 
   // Start reading
@@ -95,8 +98,8 @@ WebSocket::WebSocket(uv::Stream& stream, bool server, const private_init&)
 WebSocket::~WebSocket() = default;
 
 std::shared_ptr<WebSocket> WebSocket::CreateClient(
-    uv::Stream& stream, const Twine& uri, const Twine& host,
-    ArrayRef<StringRef> protocols, const ClientOptions& options) {
+    uv::Stream& stream, std::string_view uri, std::string_view host,
+    ArrayRef<std::string_view> protocols, const ClientOptions& options) {
   auto ws = std::make_shared<WebSocket>(stream, false, private_init{});
   stream.SetData(ws);
   ws->StartClient(uri, host, protocols, options);
@@ -104,23 +107,23 @@ std::shared_ptr<WebSocket> WebSocket::CreateClient(
 }
 
 std::shared_ptr<WebSocket> WebSocket::CreateServer(uv::Stream& stream,
-                                                   StringRef key,
-                                                   StringRef version,
-                                                   StringRef protocol) {
+                                                   std::string_view key,
+                                                   std::string_view version,
+                                                   std::string_view protocol) {
   auto ws = std::make_shared<WebSocket>(stream, true, private_init{});
   stream.SetData(ws);
   ws->StartServer(key, version, protocol);
   return ws;
 }
 
-void WebSocket::Close(uint16_t code, const Twine& reason) {
+void WebSocket::Close(uint16_t code, std::string_view reason) {
   SendClose(code, reason);
   if (m_state != FAILED && m_state != CLOSED) {
     m_state = CLOSING;
   }
 }
 
-void WebSocket::Fail(uint16_t code, const Twine& reason) {
+void WebSocket::Fail(uint16_t code, std::string_view reason) {
   if (m_state == FAILED || m_state == CLOSED) {
     return;
   }
@@ -129,7 +132,7 @@ void WebSocket::Fail(uint16_t code, const Twine& reason) {
   Shutdown();
 }
 
-void WebSocket::Terminate(uint16_t code, const Twine& reason) {
+void WebSocket::Terminate(uint16_t code, std::string_view reason) {
   if (m_state == FAILED || m_state == CLOSED) {
     return;
   }
@@ -137,8 +140,8 @@ void WebSocket::Terminate(uint16_t code, const Twine& reason) {
   Shutdown();
 }
 
-void WebSocket::StartClient(const Twine& uri, const Twine& host,
-                            ArrayRef<StringRef> protocols,
+void WebSocket::StartClient(std::string_view uri, std::string_view host,
+                            ArrayRef<std::string_view> protocols,
                             const ClientOptions& options) {
   // Create client handshake data
   m_clientHandshake = std::make_unique<ClientHandshakeData>();
@@ -187,42 +190,42 @@ void WebSocket::StartClient(const Twine& uri, const Twine& host,
   });
 
   // Set up client response handling
-  m_clientHandshake->parser.status.connect([this](StringRef status) {
+  m_clientHandshake->parser.status.connect([this](std::string_view status) {
     unsigned int code = m_clientHandshake->parser.GetStatusCode();
     if (code != 101) {
       Terminate(code, status);
     }
   });
   m_clientHandshake->parser.header.connect(
-      [this](StringRef name, StringRef value) {
-        value = value.trim();
-        if (name.equals_lower("upgrade")) {
-          if (!value.equals_lower("websocket")) {
+      [this](std::string_view name, std::string_view value) {
+        value = trim(value);
+        if (equals_lower(name, "upgrade")) {
+          if (!equals_lower(value, "websocket")) {
             return Terminate(1002, "invalid upgrade response value");
           }
           m_clientHandshake->hasUpgrade = true;
-        } else if (name.equals_lower("connection")) {
-          if (!value.equals_lower("upgrade")) {
+        } else if (equals_lower(name, "connection")) {
+          if (!equals_lower(value, "upgrade")) {
             return Terminate(1002, "invalid connection response value");
           }
           m_clientHandshake->hasConnection = true;
-        } else if (name.equals_lower("sec-websocket-accept")) {
+        } else if (equals_lower(name, "sec-websocket-accept")) {
           // Check against expected response
           SmallString<64> acceptBuf;
-          if (!value.equals(AcceptHash(m_clientHandshake->key, acceptBuf))) {
+          if (!equals(value, AcceptHash(m_clientHandshake->key, acceptBuf))) {
             return Terminate(1002, "invalid accept key");
           }
           m_clientHandshake->hasAccept = true;
-        } else if (name.equals_lower("sec-websocket-extensions")) {
+        } else if (equals_lower(name, "sec-websocket-extensions")) {
           // No extensions are supported
           if (!value.empty()) {
             return Terminate(1010, "unsupported extension");
           }
-        } else if (name.equals_lower("sec-websocket-protocol")) {
+        } else if (equals_lower(name, "sec-websocket-protocol")) {
           // Make sure it was one of the provided protocols
           bool match = false;
           for (auto&& protocol : m_clientHandshake->protocols) {
-            if (value.equals_lower(protocol)) {
+            if (equals_lower(value, protocol)) {
               match = true;
               break;
             }
@@ -257,8 +260,8 @@ void WebSocket::StartClient(const Twine& uri, const Twine& host,
   }
 }
 
-void WebSocket::StartServer(StringRef key, StringRef version,
-                            StringRef protocol) {
+void WebSocket::StartServer(std::string_view key, std::string_view version,
+                            std::string_view protocol) {
   m_protocol = protocol;
 
   // Build server response
@@ -308,14 +311,14 @@ void WebSocket::StartServer(StringRef key, StringRef version,
   });
 }
 
-void WebSocket::SendClose(uint16_t code, const Twine& reason) {
+void WebSocket::SendClose(uint16_t code, std::string_view reason) {
   SmallVector<uv::Buffer, 4> bufs;
   if (code != 1005) {
     raw_uv_ostream os{bufs, 4096};
     const uint8_t codeMsb[] = {static_cast<uint8_t>((code >> 8) & 0xff),
                                static_cast<uint8_t>(code & 0xff)};
     os << ArrayRef<uint8_t>(codeMsb);
-    reason.print(os);
+    os << reason;
   }
   Send(kFlagFin | kOpClose, bufs, [](auto bufs, uv::Error) {
     for (auto&& buf : bufs) {
@@ -324,13 +327,12 @@ void WebSocket::SendClose(uint16_t code, const Twine& reason) {
   });
 }
 
-void WebSocket::SetClosed(uint16_t code, const Twine& reason, bool failed) {
+void WebSocket::SetClosed(uint16_t code, std::string_view reason, bool failed) {
   if (m_state == FAILED || m_state == CLOSED) {
     return;
   }
   m_state = failed ? FAILED : CLOSED;
-  SmallString<64> reasonBuf;
-  closed(code, reason.toStringRef(reasonBuf));
+  closed(code, reason);
 }
 
 void WebSocket::Shutdown() {
@@ -343,7 +345,7 @@ void WebSocket::HandleIncoming(uv::Buffer& buf, size_t size) {
     return;
   }
 
-  StringRef data{buf.base, size};
+  std::string_view data{buf.base, size};
 
   // Handle connecting state (mainly on client)
   if (m_state == CONNECTING) {
@@ -372,8 +374,8 @@ void WebSocket::HandleIncoming(uv::Buffer& buf, size_t size) {
       // Need at least two bytes to determine header length
       if (m_header.size() < 2u) {
         size_t toCopy = (std::min)(2u - m_header.size(), data.size());
-        m_header.append(data.bytes_begin(), data.bytes_begin() + toCopy);
-        data = data.drop_front(toCopy);
+        m_header.append(data.data(), data.data() + toCopy);
+        data.remove_prefix(toCopy);
         if (m_header.size() < 2u) {
           return;  // need more data
         }
@@ -410,8 +412,8 @@ void WebSocket::HandleIncoming(uv::Buffer& buf, size_t size) {
       // Need to complete header to calculate message size
       if (m_header.size() < m_headerSize) {
         size_t toCopy = (std::min)(m_headerSize - m_header.size(), data.size());
-        m_header.append(data.bytes_begin(), data.bytes_begin() + toCopy);
-        data = data.drop_front(toCopy);
+        m_header.append(data.data(), data.data() + toCopy);
+        data.remove_prefix(toCopy);
         if (m_header.size() < m_headerSize) {
           return;  // need more data
         }
@@ -446,8 +448,8 @@ void WebSocket::HandleIncoming(uv::Buffer& buf, size_t size) {
     if (m_frameSize != UINT64_MAX) {
       size_t need = m_frameStart + m_frameSize - m_payload.size();
       size_t toCopy = (std::min)(need, data.size());
-      m_payload.append(data.bytes_begin(), data.bytes_begin() + toCopy);
-      data = data.drop_front(toCopy);
+      m_payload.append(data.data(), data.data() + toCopy);
+      data.remove_prefix(toCopy);
       need -= toCopy;
       if (need == 0) {
         // We have a complete frame
@@ -474,8 +476,9 @@ void WebSocket::HandleIncoming(uv::Buffer& buf, size_t size) {
             switch (m_fragmentOpcode) {
               case kOpText:
                 if (!m_combineFragments || fin) {
-                  text(StringRef{reinterpret_cast<char*>(m_payload.data()),
-                                 m_payload.size()},
+                  text(std::string_view{reinterpret_cast<char*>(
+                                            m_payload.data()),
+                                        m_payload.size()},
                        fin);
                 }
                 break;
@@ -497,8 +500,8 @@ void WebSocket::HandleIncoming(uv::Buffer& buf, size_t size) {
               return Fail(1002, "incomplete fragment");
             }
             if (!m_combineFragments || fin) {
-              text(StringRef{reinterpret_cast<char*>(m_payload.data()),
-                             m_payload.size()},
+              text(std::string_view{reinterpret_cast<char*>(m_payload.data()),
+                                    m_payload.size()},
                    fin);
             }
             if (!fin) {
@@ -518,7 +521,7 @@ void WebSocket::HandleIncoming(uv::Buffer& buf, size_t size) {
             break;
           case kOpClose: {
             uint16_t code;
-            StringRef reason;
+            std::string_view reason;
             if (!fin) {
               code = 1002;
               reason = "cannot fragment control frames";
@@ -527,9 +530,9 @@ void WebSocket::HandleIncoming(uv::Buffer& buf, size_t size) {
             } else {
               code = (static_cast<uint16_t>(m_payload[0]) << 8) |
                      static_cast<uint16_t>(m_payload[1]);
-              reason = StringRef{reinterpret_cast<char*>(m_payload.data()),
-                                 m_payload.size()}
-                           .drop_front(2);
+              reason = drop_front(
+                  {reinterpret_cast<char*>(m_payload.data()), m_payload.size()},
+                  2);
             }
             // Echo the close if we didn't previously send it
             if (m_state != CLOSING) {
diff --git a/wpiutil/src/main/native/cpp/WebSocketServer.cpp b/wpiutil/src/main/native/cpp/WebSocketServer.cpp
index 637ceff104..45b9fda7b2 100644
--- a/wpiutil/src/main/native/cpp/WebSocketServer.cpp
+++ b/wpiutil/src/main/native/cpp/WebSocketServer.cpp
@@ -6,6 +6,8 @@
 
 #include <utility>
 
+#include "wpi/StringExtras.h"
+#include "wpi/fmt/raw_ostream.h"
 #include "wpi/raw_uv_ostream.h"
 #include "wpi/uv/Buffer.h"
 #include "wpi/uv/Stream.h"
@@ -13,23 +15,23 @@
 using namespace wpi;
 
 WebSocketServerHelper::WebSocketServerHelper(HttpParser& req) {
-  req.header.connect([this](StringRef name, StringRef value) {
-    if (name.equals_lower("host")) {
+  req.header.connect([this](std::string_view name, std::string_view value) {
+    if (equals_lower(name, "host")) {
       m_gotHost = true;
-    } else if (name.equals_lower("upgrade")) {
-      if (value.equals_lower("websocket")) {
+    } else if (equals_lower(name, "upgrade")) {
+      if (equals_lower(value, "websocket")) {
         m_websocket = true;
       }
-    } else if (name.equals_lower("sec-websocket-key")) {
+    } else if (equals_lower(name, "sec-websocket-key")) {
       m_key = value;
-    } else if (name.equals_lower("sec-websocket-version")) {
+    } else if (equals_lower(name, "sec-websocket-version")) {
       m_version = value;
-    } else if (name.equals_lower("sec-websocket-protocol")) {
+    } else if (equals_lower(name, "sec-websocket-protocol")) {
       // Protocols are comma delimited, repeated headers add to list
-      SmallVector<StringRef, 2> protocols;
-      value.split(protocols, ",", -1, false);
+      SmallVector<std::string_view, 2> protocols;
+      split(value, protocols, ",", -1, false);
       for (auto protocol : protocols) {
-        protocol = protocol.trim();
+        protocol = trim(protocol);
         if (!protocol.empty()) {
           m_protocols.emplace_back(protocol);
         }
@@ -43,31 +45,31 @@ WebSocketServerHelper::WebSocketServerHelper(HttpParser& req) {
   });
 }
 
-std::pair<bool, StringRef> WebSocketServerHelper::MatchProtocol(
-    ArrayRef<StringRef> protocols) {
+std::pair<bool, std::string_view> WebSocketServerHelper::MatchProtocol(
+    ArrayRef<std::string_view> protocols) {
   if (protocols.empty() && m_protocols.empty()) {
-    return std::make_pair(true, StringRef{});
+    return {true, {}};
   }
   for (auto protocol : protocols) {
     for (auto&& clientProto : m_protocols) {
       if (protocol == clientProto) {
-        return std::make_pair(true, protocol);
+        return {true, protocol};
       }
     }
   }
-  return std::make_pair(false, StringRef{});
+  return {false, {}};
 }
 
 WebSocketServer::WebSocketServer(uv::Stream& stream,
-                                 ArrayRef<StringRef> protocols,
+                                 ArrayRef<std::string_view> protocols,
                                  ServerOptions options, const private_init&)
     : m_stream{stream},
       m_helper{m_req},
       m_protocols{protocols.begin(), protocols.end()},
       m_options{std::move(options)} {
   // Header handling
-  m_req.header.connect([this](StringRef name, StringRef value) {
-    if (name.equals_lower("host")) {
+  m_req.header.connect([this](std::string_view name, std::string_view value) {
+    if (equals_lower(name, "host")) {
       if (m_options.checkHost) {
         if (!m_options.checkHost(value)) {
           Abort(401, "Unrecognized Host");
@@ -75,7 +77,7 @@ WebSocketServer::WebSocketServer(uv::Stream& stream,
       }
     }
   });
-  m_req.url.connect([this](StringRef name) {
+  m_req.url.connect([this](std::string_view name) {
     if (m_options.checkUrl) {
       if (!m_options.checkUrl(name)) {
         Abort(404, "Not Found");
@@ -96,8 +98,9 @@ WebSocketServer::WebSocketServer(uv::Stream& stream,
     }
 
     // Negotiate sub-protocol
-    SmallVector<StringRef, 2> protocols{m_protocols.begin(), m_protocols.end()};
-    StringRef protocol = m_helper.MatchProtocol(protocols).second;
+    SmallVector<std::string_view, 2> protocols{m_protocols.begin(),
+                                               m_protocols.end()};
+    std::string_view protocol = m_helper.MatchProtocol(protocols).second;
 
     // Disconnect our header reader
     m_dataConn.disconnect();
@@ -110,10 +113,11 @@ WebSocketServer::WebSocketServer(uv::Stream& stream,
     auto ws = m_helper.Accept(m_stream, protocol);
 
     // Connect the websocket open event to our connected event.
-    ws->open.connect_extended([self, s = ws.get()](auto conn, StringRef) {
-      self->connected(self->m_req.GetUrl(), *s);
-      conn.disconnect();  // one-shot
-    });
+    ws->open.connect_extended(
+        [self, s = ws.get()](auto conn, std::string_view) {
+          self->connected(self->m_req.GetUrl(), *s);
+          conn.disconnect();  // one-shot
+        });
   });
 
   // Set up stream
@@ -123,7 +127,7 @@ WebSocketServer::WebSocketServer(uv::Stream& stream,
         if (m_aborted) {
           return;
         }
-        m_req.Execute(StringRef{buf.base, size});
+        m_req.Execute(std::string_view{buf.base, size});
         if (m_req.HasError()) {
           Abort(400, "Bad Request");
         }
@@ -134,7 +138,7 @@ WebSocketServer::WebSocketServer(uv::Stream& stream,
 }
 
 std::shared_ptr<WebSocketServer> WebSocketServer::Create(
-    uv::Stream& stream, ArrayRef<StringRef> protocols,
+    uv::Stream& stream, ArrayRef<std::string_view> protocols,
     const ServerOptions& options) {
   auto server = std::make_shared<WebSocketServer>(stream, protocols, options,
                                                   private_init{});
@@ -142,7 +146,7 @@ std::shared_ptr<WebSocketServer> WebSocketServer::Create(
   return server;
 }
 
-void WebSocketServer::Abort(uint16_t code, StringRef reason) {
+void WebSocketServer::Abort(uint16_t code, std::string_view reason) {
   if (m_aborted) {
     return;
   }
@@ -153,7 +157,7 @@ void WebSocketServer::Abort(uint16_t code, StringRef reason) {
   raw_uv_ostream os{bufs, 1024};
 
   // Handle unsupported version
-  os << "HTTP/1.1 " << code << ' ' << reason << "\r\n";
+  fmt::print(os, "HTTP/1.1 {} {}\r\n", code, reason);
   if (code == 426) {
     os << "Upgrade: WebSocket\r\n";
   }
diff --git a/wpiutil/src/main/native/cpp/hostname.cpp b/wpiutil/src/main/native/cpp/hostname.cpp
index 939ed223e7..d907023ff4 100644
--- a/wpiutil/src/main/native/cpp/hostname.cpp
+++ b/wpiutil/src/main/native/cpp/hostname.cpp
@@ -6,10 +6,10 @@
 
 #include <cstdlib>
 #include <string>
+#include <string_view>
 
 #include "uv.h"
 #include "wpi/SmallVector.h"
-#include "wpi/StringRef.h"
 
 namespace wpi {
 
@@ -33,7 +33,7 @@ std::string GetHostname() {
   return rv;
 }
 
-StringRef GetHostname(SmallVectorImpl<char>& name) {
+std::string_view GetHostname(SmallVectorImpl<char>& name) {
   // Use a tmp array to not require the SmallVector to be too large.
   char tmpName[256];
   size_t size = sizeof(tmpName);
@@ -51,7 +51,7 @@ StringRef GetHostname(SmallVectorImpl<char>& name) {
     }
   }
 
-  return StringRef{name.data(), size};
+  return {name.data(), size};
 }
 
 }  // namespace wpi
diff --git a/wpiutil/src/main/native/cpp/json.cpp b/wpiutil/src/main/native/cpp/json.cpp
index ba9cd8ef7a..f1cfb14ca2 100644
--- a/wpiutil/src/main/native/cpp/json.cpp
+++ b/wpiutil/src/main/native/cpp/json.cpp
@@ -34,39 +34,51 @@ SOFTWARE.
 #define WPI_JSON_IMPLEMENTATION
 #include "wpi/json.h"
 
+#include "fmt/format.h"
 #include "wpi/raw_ostream.h"
 
 namespace wpi {
 namespace detail {
 
-exception::exception(int id_, const Twine& what_arg)
-    : id(id_), m(what_arg.str()) {}
+exception::exception(int id_, std::string_view what_arg)
+    : id(id_), m(std::string{what_arg}) {}
 
-parse_error parse_error::create(int id_, std::size_t byte_, const Twine& what_arg)
+parse_error parse_error::create(int id_, std::size_t byte_, std::string_view what_arg)
 {
-    return parse_error(id_, byte_, "[json.exception.parse_error." + Twine(id_) + "] parse error" +
-                    (byte_ != 0 ? (" at " + Twine(byte_)) : Twine("")) +
-                    ": " + what_arg);
+    if (byte_ != 0)
+        return parse_error(id_, byte_, fmt::format("[json.exception.parse_error.{}] parse error at {}: {}", id_, byte_, what_arg));
+    else
+        return parse_error(id_, byte_, fmt::format("[json.exception.parse_error.{}] parse error: {}", id_, what_arg));
 }
 
-invalid_iterator invalid_iterator::create(int id_, const Twine& what_arg)
+invalid_iterator invalid_iterator::create(int id_, std::string_view what_arg)
 {
-    return invalid_iterator(id_, "[json.exception.invalid_iterator." + Twine(id_) + "] " + what_arg);
+    return invalid_iterator(id_, fmt::format("[json.exception.invalid_iterator.{}] {}", id_, what_arg));
 }
 
-type_error type_error::create(int id_, const Twine& what_arg)
+invalid_iterator invalid_iterator::create(int id_, std::string_view what_arg, std::string_view type_info)
 {
-    return type_error(id_, "[json.exception.type_error." + Twine(id_) + "] " + what_arg);
+    return invalid_iterator(id_, fmt::format("[json.exception.invalid_iterator.{}] {} {}", id_, what_arg, type_info));
 }
 
-out_of_range out_of_range::create(int id_, const Twine& what_arg)
+type_error type_error::create(int id_, std::string_view what_arg)
 {
-    return out_of_range(id_, "[json.exception.out_of_range." + Twine(id_) + "] " + what_arg);
+    return type_error(id_, fmt::format("[json.exception.type_error.{}] {}", id_, what_arg));
 }
 
-other_error other_error::create(int id_, const Twine& what_arg)
+type_error type_error::create(int id_, std::string_view what_arg, std::string_view type_info)
 {
-    return other_error(id_, "[json.exception.other_error." + Twine(id_) + "] " + what_arg);
+    return type_error(id_, fmt::format("[json.exception.type_error.{}] {} {}", id_, what_arg, type_info));
+}
+
+out_of_range out_of_range::create(int id_, std::string_view what_arg)
+{
+    return out_of_range(id_, fmt::format("[json.exception.out_of_range.{}] {}", id_, what_arg));
+}
+
+other_error other_error::create(int id_, std::string_view what_arg)
+{
+    return other_error(id_, fmt::format("[json.exception.other_error.{}] {}", id_, what_arg));
 }
 
 }  // namespace detail
@@ -353,12 +365,12 @@ json::reference json::at(size_type idx)
         JSON_CATCH (std::out_of_range&)
         {
             // create better exception explanation
-            JSON_THROW(out_of_range::create(401, "array index " + Twine(idx) + " is out of range"));
+            JSON_THROW(out_of_range::create(401, fmt::format("array index {} is out of range", idx)));
         }
     }
     else
     {
-        JSON_THROW(type_error::create(304, "cannot use at() with " + Twine(type_name())));
+        JSON_THROW(type_error::create(304, "cannot use at() with", type_name()));
     }
 }
 
@@ -374,16 +386,16 @@ json::const_reference json::at(size_type idx) const
         JSON_CATCH (std::out_of_range&)
         {
             // create better exception explanation
-            JSON_THROW(out_of_range::create(401, "array index " + Twine(idx) + " is out of range"));
+            JSON_THROW(out_of_range::create(401, fmt::format("array index {} is out of range", idx)));
         }
     }
     else
     {
-        JSON_THROW(type_error::create(304, "cannot use at() with " + Twine(type_name())));
+        JSON_THROW(type_error::create(304, "cannot use at() with", type_name()));
     }
 }
 
-json::reference json::at(StringRef key)
+json::reference json::at(std::string_view key)
 {
     // at only works for objects
     if (JSON_LIKELY(is_object()))
@@ -392,17 +404,17 @@ json::reference json::at(StringRef key)
         if (it == m_value.object->end())
         {
             // create better exception explanation
-            JSON_THROW(out_of_range::create(403, "key '" + Twine(key) + "' not found"));
+            JSON_THROW(out_of_range::create(403, fmt::format("key '{}' not found", key)));
         }
         return it->second;
     }
     else
     {
-        JSON_THROW(type_error::create(304, "cannot use at() with " + Twine(type_name())));
+        JSON_THROW(type_error::create(304, "cannot use at() with", type_name()));
     }
 }
 
-json::const_reference json::at(StringRef key) const
+json::const_reference json::at(std::string_view key) const
 {
     // at only works for objects
     if (JSON_LIKELY(is_object()))
@@ -411,13 +423,13 @@ json::const_reference json::at(StringRef key) const
         if (it == m_value.object->end())
         {
             // create better exception explanation
-            JSON_THROW(out_of_range::create(403, "key '" + Twine(key) + "' not found"));
+            JSON_THROW(out_of_range::create(403, fmt::format("key '{}' not found", key)));
         }
         return it->second;
     }
     else
     {
-        JSON_THROW(type_error::create(304, "cannot use at() with " + Twine(type_name())));
+        JSON_THROW(type_error::create(304, "cannot use at() with", type_name()));
     }
 }
 
@@ -445,7 +457,7 @@ json::reference json::operator[](size_type idx)
         return m_value.array->operator[](idx);
     }
 
-    JSON_THROW(type_error::create(305, "cannot use operator[] with " + Twine(type_name())));
+    JSON_THROW(type_error::create(305, "cannot use operator[] with", type_name()));
 }
 
 json::const_reference json::operator[](size_type idx) const
@@ -456,10 +468,10 @@ json::const_reference json::operator[](size_type idx) const
         return m_value.array->operator[](idx);
     }
 
-    JSON_THROW(type_error::create(305, "cannot use operator[] with " + Twine(type_name())));
+    JSON_THROW(type_error::create(305, "cannot use operator[] with", type_name()));
 }
 
-json::reference json::operator[](StringRef key)
+json::reference json::operator[](std::string_view key)
 {
     // implicitly convert null value to an empty object
     if (is_null())
@@ -475,10 +487,10 @@ json::reference json::operator[](StringRef key)
         return m_value.object->operator[](key);
     }
 
-    JSON_THROW(type_error::create(305, "cannot use operator[] with " + Twine(type_name())));
+    JSON_THROW(type_error::create(305, "cannot use operator[] with", type_name()));
 }
 
-json::const_reference json::operator[](StringRef key) const
+json::const_reference json::operator[](std::string_view key) const
 {
     // const operator[] only works for objects
     if (JSON_LIKELY(is_object()))
@@ -487,10 +499,10 @@ json::const_reference json::operator[](StringRef key) const
         return m_value.object->find(key)->second;
     }
 
-    JSON_THROW(type_error::create(305, "cannot use operator[] with " + Twine(type_name())));
+    JSON_THROW(type_error::create(305, "cannot use operator[] with", type_name()));
 }
 
-json::size_type json::erase(StringRef key)
+json::size_type json::erase(std::string_view key)
 {
     // this erase only works for objects
     if (JSON_LIKELY(is_object()))
@@ -498,7 +510,7 @@ json::size_type json::erase(StringRef key)
         return m_value.object->erase(key);
     }
 
-    JSON_THROW(type_error::create(307, "cannot use erase() with " + Twine(type_name())));
+    JSON_THROW(type_error::create(307, "cannot use erase() with", type_name()));
 }
 
 void json::erase(const size_type idx)
@@ -508,18 +520,18 @@ void json::erase(const size_type idx)
     {
         if (JSON_UNLIKELY(idx >= size()))
         {
-            JSON_THROW(out_of_range::create(401, "array index " + Twine(idx) + " is out of range"));
+            JSON_THROW(out_of_range::create(401, fmt::format("array index {} is out of range", idx)));
         }
 
         m_value.array->erase(m_value.array->begin() + static_cast<difference_type>(idx));
     }
     else
     {
-        JSON_THROW(type_error::create(307, "cannot use erase() with " + Twine(type_name())));
+        JSON_THROW(type_error::create(307, "cannot use erase() with", type_name()));
     }
 }
 
-json::iterator json::find(StringRef key)
+json::iterator json::find(std::string_view key)
 {
     auto result = end();
 
@@ -531,7 +543,7 @@ json::iterator json::find(StringRef key)
     return result;
 }
 
-json::const_iterator json::find(StringRef key) const
+json::const_iterator json::find(std::string_view key) const
 {
     auto result = cend();
 
@@ -543,7 +555,7 @@ json::const_iterator json::find(StringRef key) const
     return result;
 }
 
-json::size_type json::count(StringRef key) const
+json::size_type json::count(std::string_view key) const
 {
     // return 0 for all nonobject types
     return is_object() ? m_value.object->count(key) : 0;
@@ -689,7 +701,7 @@ void json::push_back(json&& val)
     // push_back only works for null objects or arrays
     if (JSON_UNLIKELY(not(is_null() or is_array())))
     {
-        JSON_THROW(type_error::create(308, "cannot use push_back() with " + Twine(type_name())));
+        JSON_THROW(type_error::create(308, "cannot use push_back() with", type_name()));
     }
 
     // transform null object into an array
@@ -711,7 +723,7 @@ void json::push_back(const json& val)
     // push_back only works for null objects or arrays
     if (JSON_UNLIKELY(not(is_null() or is_array())))
     {
-        JSON_THROW(type_error::create(308, "cannot use push_back() with " + Twine(type_name())));
+        JSON_THROW(type_error::create(308, "cannot use push_back() with", type_name()));
     }
 
     // transform null object into an array
@@ -731,7 +743,7 @@ void json::push_back(initializer_list_t init)
     if (is_object() and init.size() == 2 and (*init.begin())->is_string())
     {
         std::string key = init.begin()->moved_or_copied();
-        push_back(std::pair<StringRef, json>(key, (init.begin() + 1)->moved_or_copied()));
+        push_back(std::pair<std::string_view, json>(key, (init.begin() + 1)->moved_or_copied()));
     }
     else
     {
@@ -756,7 +768,7 @@ json::iterator json::insert(const_iterator pos, const json& val)
         return result;
     }
 
-    JSON_THROW(type_error::create(309, "cannot use insert() with " + Twine(type_name())));
+    JSON_THROW(type_error::create(309, "cannot use insert() with", type_name()));
 }
 
 json::iterator json::insert(const_iterator pos, size_type cnt, const json& val)
@@ -776,7 +788,7 @@ json::iterator json::insert(const_iterator pos, size_type cnt, const json& val)
         return result;
     }
 
-    JSON_THROW(type_error::create(309, "cannot use insert() with " + Twine(type_name())));
+    JSON_THROW(type_error::create(309, "cannot use insert() with", type_name()));
 }
 
 json::iterator json::insert(const_iterator pos, const_iterator first, const_iterator last)
@@ -784,7 +796,7 @@ json::iterator json::insert(const_iterator pos, const_iterator first, const_iter
     // insert only works for arrays
     if (JSON_UNLIKELY(not is_array()))
     {
-        JSON_THROW(type_error::create(309, "cannot use insert() with " + Twine(type_name())));
+        JSON_THROW(type_error::create(309, "cannot use insert() with", type_name()));
     }
 
     // check if iterator pos fits to this JSON value
@@ -818,7 +830,7 @@ json::iterator json::insert(const_iterator pos, initializer_list_t ilist)
     // insert only works for arrays
     if (JSON_UNLIKELY(not is_array()))
     {
-        JSON_THROW(type_error::create(309, "cannot use insert() with " + Twine(type_name())));
+        JSON_THROW(type_error::create(309, "cannot use insert() with", type_name()));
     }
 
     // check if iterator pos fits to this JSON value
@@ -838,7 +850,7 @@ void json::insert(const_iterator first, const_iterator last)
     // insert only works for objects
     if (JSON_UNLIKELY(not is_object()))
     {
-        JSON_THROW(type_error::create(309, "cannot use insert() with " + Twine(type_name())));
+        JSON_THROW(type_error::create(309, "cannot use insert() with", type_name()));
     }
 
     // check if range iterators belong to the same JSON object
@@ -871,11 +883,11 @@ void json::update(const_reference j)
 
     if (JSON_UNLIKELY(not is_object()))
     {
-        JSON_THROW(type_error::create(312, "cannot use update() with " + Twine(type_name())));
+        JSON_THROW(type_error::create(312, "cannot use update() with", type_name()));
     }
     if (JSON_UNLIKELY(not j.is_object()))
     {
-        JSON_THROW(type_error::create(312, "cannot use update() with " + Twine(j.type_name())));
+        JSON_THROW(type_error::create(312, "cannot use update() with", j.type_name()));
     }
 
     for (auto it = j.cbegin(); it != j.cend(); ++it)
@@ -896,7 +908,7 @@ void json::update(const_iterator first, const_iterator last)
 
     if (JSON_UNLIKELY(not is_object()))
     {
-        JSON_THROW(type_error::create(312, "cannot use update() with " + Twine(type_name())));
+        JSON_THROW(type_error::create(312, "cannot use update() with", type_name()));
     }
 
     // check if range iterators belong to the same JSON object
@@ -1156,7 +1168,7 @@ json json::patch(const json& json_patch) const
                         if (JSON_UNLIKELY(static_cast<size_type>(idx) > parent.size()))
                         {
                             // avoid undefined behavior
-                            JSON_THROW(out_of_range::create(401, "array index " + Twine(idx) + " is out of range"));
+                            JSON_THROW(out_of_range::create(401, fmt::format("array index {} is out of range", idx)));
                         }
                         else
                         {
@@ -1194,7 +1206,7 @@ json json::patch(const json& json_patch) const
             }
             else
             {
-                JSON_THROW(out_of_range::create(403, "key '" + Twine(last_path) + "' not found"));
+                JSON_THROW(out_of_range::create(403, fmt::format("key '{}' not found", last_path)));
             }
         }
         else if (parent.is_array())
@@ -1227,13 +1239,13 @@ json json::patch(const json& json_patch) const
             // check if desired value is present
             if (JSON_UNLIKELY(it == val.m_value.object->end()))
             {
-                JSON_THROW(parse_error::create(105, 0, Twine(error_msg) + " must have member '" + Twine(member) + "'"));
+                JSON_THROW(parse_error::create(105, 0, fmt::format("{} must have member '{}'", error_msg, member)));
             }
 
             // check if result is of type string
             if (JSON_UNLIKELY(string_type and not it->second.is_string()))
             {
-                JSON_THROW(parse_error::create(105, 0, Twine(error_msg) + " must have string member '" + Twine(member) + "'"));
+                JSON_THROW(parse_error::create(105, 0, fmt::format("{} must have string member '{}'", error_msg, member)));
             }
 
             // no error: return value
@@ -1321,7 +1333,7 @@ json json::patch(const json& json_patch) const
                 // throw an exception if test fails
                 if (JSON_UNLIKELY(not success))
                 {
-                    JSON_THROW(other_error::create(501, "unsuccessful: " + Twine(val.dump())));
+                    JSON_THROW(other_error::create(501, fmt::format("unsuccessful: {}", val.dump())));
                 }
 
                 break;
@@ -1331,7 +1343,7 @@ json json::patch(const json& json_patch) const
             {
                 // op must be "add", "remove", "replace", "move", "copy", or
                 // "test"
-                JSON_THROW(parse_error::create(105, 0, "operation value '" + Twine(op) + "' is invalid"));
+                JSON_THROW(parse_error::create(105, 0, fmt::format("operation value '{}' is invalid", op)));
             }
         }
     }
@@ -1413,7 +1425,7 @@ json json::diff(const json& source, const json& target,
                 for (auto it = source.cbegin(); it != source.cend(); ++it)
                 {
                     // escape the key name to be used in a JSON patch
-                    const auto key = json_pointer::escape(it.key());
+                    const auto key = json_pointer::escape(std::string{it.key()});
 
                     if (target.find(it.key()) != target.end())
                     {
@@ -1437,7 +1449,7 @@ json json::diff(const json& source, const json& target,
                     if (source.find(it.key()) == source.end())
                     {
                         // found a key that is not in this -> add it
-                        const auto key = json_pointer::escape(it.key());
+                        const auto key = json_pointer::escape(std::string{it.key()});
                         result.push_back(
                         {
                             {"op", "add"}, {"path", path + "/" + key},
diff --git a/wpiutil/src/main/native/cpp/json_binary_reader.cpp b/wpiutil/src/main/native/cpp/json_binary_reader.cpp
index 9298e924f0..86d28332cf 100644
--- a/wpiutil/src/main/native/cpp/json_binary_reader.cpp
+++ b/wpiutil/src/main/native/cpp/json_binary_reader.cpp
@@ -36,6 +36,7 @@ SOFTWARE.
 
 #include <cmath>  // ldexp
 
+#include "fmt/format.h"
 #include "wpi/raw_istream.h"
 
 namespace wpi {
@@ -711,7 +712,7 @@ json json::binary_reader::parse_cbor_internal(const bool get_char)
 
         default: // anything else (0xFF is handled inside the other types)
         {
-            JSON_THROW(parse_error::create(112, chars_read, "error reading CBOR; last byte: 0x" + Twine::utohexstr(current)));
+            JSON_THROW(parse_error::create(112, chars_read, fmt::format("error reading CBOR; last byte: {:#02x}", current)));
         }
     }
 }
@@ -1034,7 +1035,7 @@ json json::binary_reader::parse_msgpack_internal()
         default: // anything else
         {
             JSON_THROW(parse_error::create(112, chars_read,
-                                           "error reading MessagePack; last byte: 0x" + Twine::utohexstr(current)));
+                fmt::format("error reading MessagePack; last byte: {:#02x}", current)));
         }
     }
 }
@@ -1106,7 +1107,8 @@ std::string json::binary_reader::get_cbor_string()
 
         default:
         {
-            JSON_THROW(parse_error::create(113, chars_read, "expected a CBOR string; last byte: 0x" + Twine::utohexstr(current)));
+            JSON_THROW(parse_error::create(113, chars_read,
+                fmt::format("expected a CBOR string; last byte: {:#02x}", current)));
         }
     }
 }
@@ -1172,7 +1174,7 @@ std::string json::binary_reader::get_msgpack_string()
         default:
         {
             JSON_THROW(parse_error::create(113, chars_read,
-                                           "expected a MessagePack string; last byte: 0x" + Twine::utohexstr(current)));
+                fmt::format("expected a MessagePack string; last byte: {:#02x}", current)));
         }
     }
 }
@@ -1200,7 +1202,7 @@ std::string json::binary_reader::get_ubjson_string(const bool get_char)
             return get_string(get_number<int64_t>());
         default:
             JSON_THROW(parse_error::create(113, chars_read,
-                                           "expected a UBJSON string; last byte: 0x" + Twine::utohexstr(current)));
+                fmt::format("expected a UBJSON string; last byte: {:#02x}", current)));
     }
 }
 
@@ -1220,7 +1222,7 @@ std::pair<std::size_t, int> json::binary_reader::get_ubjson_size_type()
         if (current != '#')
         {
             JSON_THROW(parse_error::create(112, chars_read,
-                                           "expected '#' after UBJSON type information; last byte: 0x" + Twine::utohexstr(current)));
+                fmt::format("expected '#' after UBJSON type information; last byte: {:#02x}", current)));
         }
         sz = parse_ubjson_internal();
     }
@@ -1269,7 +1271,7 @@ json json::binary_reader::get_ubjson_value(const int prefix)
             if (JSON_UNLIKELY(current > 127))
             {
                 JSON_THROW(parse_error::create(113, chars_read,
-                                               "byte after 'C' must be in range 0x00..0x7F; last byte: 0x" + Twine::utohexstr(current)));
+                    fmt::format("byte after 'C' must be in range 0x00..0x7F; last byte: {:#02x}", current)));
             }
             return std::string(1, static_cast<char>(current));
         }
@@ -1285,7 +1287,7 @@ json json::binary_reader::get_ubjson_value(const int prefix)
 
         default: // anything else
             JSON_THROW(parse_error::create(112, chars_read,
-                                           "error reading UBJSON; last byte: 0x" + Twine::utohexstr(current)));
+                fmt::format("error reading UBJSON; last byte: {:#02x}", current)));
     }
 }
 
@@ -1299,7 +1301,7 @@ json json::binary_reader::get_ubjson_array()
         if (JSON_UNLIKELY(size_and_type.first > result.max_size()))
         {
             JSON_THROW(out_of_range::create(408,
-                                            "excessive array size: " + Twine(size_and_type.first)));
+                fmt::format("excessive array size: {}", size_and_type.first)));
         }
 
         if (size_and_type.second != 0)
@@ -1344,7 +1346,7 @@ json json::binary_reader::get_ubjson_object()
         if (JSON_UNLIKELY(size_and_type.first > result.max_size()))
         {
             JSON_THROW(out_of_range::create(408,
-                                            "excessive object size: " + Twine(size_and_type.first)));
+                fmt::format("excessive object size: {}", size_and_type.first)));
         }
 
         if (size_and_type.second != 0)
diff --git a/wpiutil/src/main/native/cpp/json_binary_writer.cpp b/wpiutil/src/main/native/cpp/json_binary_writer.cpp
index 2c0bbeea70..0b6e6b7a16 100644
--- a/wpiutil/src/main/native/cpp/json_binary_writer.cpp
+++ b/wpiutil/src/main/native/cpp/json_binary_writer.cpp
@@ -34,6 +34,7 @@ SOFTWARE.
 #define WPI_JSON_IMPLEMENTATION
 #include "wpi/json.h"
 
+#include "fmt/format.h"
 #include "wpi/raw_ostream.h"
 
 namespace wpi {
@@ -75,9 +76,9 @@ class json::binary_writer
                       const bool use_type, const bool add_prefix = true);
 
   private:
-    void write_cbor_string(StringRef str);
+    void write_cbor_string(std::string_view str);
 
-    void write_msgpack_string(StringRef str);
+    void write_msgpack_string(std::string_view str);
 
     /*
     @brief write a number to output input
@@ -630,7 +631,7 @@ void json::binary_writer::write_ubjson(const json& j, const bool use_count,
                 o << static_cast<CharType>('S');
             }
             write_number_with_ubjson_prefix(j.m_value.string->size(), true);
-            o << j.m_value.string;
+            o << *j.m_value.string;
             break;
         }
 
@@ -731,7 +732,7 @@ void json::binary_writer::write_ubjson(const json& j, const bool use_count,
     }
 }
 
-void json::binary_writer::write_cbor_string(StringRef str)
+void json::binary_writer::write_cbor_string(std::string_view str)
 {
     // step 1: write control byte and the string length
     const auto N = str.size();
@@ -766,7 +767,7 @@ void json::binary_writer::write_cbor_string(StringRef str)
     o << str;
 }
 
-void json::binary_writer::write_msgpack_string(StringRef str)
+void json::binary_writer::write_msgpack_string(std::string_view str)
 {
     // step 1: write control byte and the string length
     const auto N = str.size();
@@ -862,7 +863,7 @@ void json::binary_writer::write_number_with_ubjson_prefix(const NumberType n,
     }
     else
     {
-        JSON_THROW(out_of_range::create(407, "number overflow serializing " + Twine(n)));
+        JSON_THROW(out_of_range::create(407, fmt::format("number overflow serializing {}", n)));
     }
 }
 
@@ -915,7 +916,7 @@ void json::binary_writer::write_number_with_ubjson_prefix(const NumberType n,
     // LCOV_EXCL_START
     else
     {
-        JSON_THROW(out_of_range::create(407, "number overflow serializing " + Twine(n)));
+        JSON_THROW(out_of_range::create(407, fmt::format("number overflow serializing {}", n)));
     }
     // LCOV_EXCL_STOP
 }
diff --git a/wpiutil/src/main/native/cpp/json_parser.cpp b/wpiutil/src/main/native/cpp/json_parser.cpp
index e0d7db36c4..bae8c118b6 100644
--- a/wpiutil/src/main/native/cpp/json_parser.cpp
+++ b/wpiutil/src/main/native/cpp/json_parser.cpp
@@ -38,7 +38,7 @@ SOFTWARE.
 #include <cmath>
 #include <cstdlib>
 
-#include "wpi/Format.h"
+#include "fmt/format.h"
 #include "wpi/SmallString.h"
 #include "wpi/raw_istream.h"
 #include "wpi/raw_ostream.h"
@@ -336,7 +336,7 @@ class json::lexer
     }
 
     /// return current string value
-    StringRef get_string()
+    std::string_view get_string()
     {
         return token_buffer;
     }
@@ -1407,7 +1407,7 @@ std::string json::lexer::get_token_string() const
         if (c <= '\x1F')
         {
             // escape control characters
-            ss << "<U+" << format_hex_no_prefix(c, 4, true) << '>';
+            ss << fmt::format("<U+{:04X}>", c);
         }
         else
         {
@@ -1605,7 +1605,7 @@ void json::parser::parse_internal(bool keep, json& result)
 
                 if (keep and keep_tag and not value.is_discarded())
                 {
-                    result.m_value.object->try_emplace(StringRef(key.data(), key.size()), std::move(value));
+                    result.m_value.object->try_emplace(std::string_view(key.data(), key.size()), std::move(value));
                 }
 
                 // comma -> next value
@@ -1757,8 +1757,8 @@ void json::parser::parse_internal(bool keep, json& result)
             {
                 if (allow_exceptions)
                 {
-                    JSON_THROW(out_of_range::create(406, "number overflow parsing '" +
-                                                    Twine(m_lexer.get_token_string()) + "'"));
+                    JSON_THROW(out_of_range::create(406,
+                        fmt::format("number overflow parsing '{}'", m_lexer.get_token_string())));
                 }
                 expect(token_type::uninitialized);
             }
@@ -1917,7 +1917,7 @@ void json::parser::throw_exception() const
     JSON_THROW(parse_error::create(101, m_lexer.get_position(), error_msg));
 }
 
-json json::parse(StringRef s,
+json json::parse(std::string_view s,
                         const parser_callback_t cb,
                         const bool allow_exceptions)
 {
@@ -1942,7 +1942,7 @@ json json::parse(raw_istream& i,
     return result;
 }
 
-bool json::accept(StringRef s)
+bool json::accept(std::string_view s)
 {
     raw_mem_istream is(makeArrayRef(s.data(), s.size()));
     return parser(is).accept(true);
diff --git a/wpiutil/src/main/native/cpp/json_pointer.cpp b/wpiutil/src/main/native/cpp/json_pointer.cpp
index 9cb1ec4fc3..51548b39c6 100644
--- a/wpiutil/src/main/native/cpp/json_pointer.cpp
+++ b/wpiutil/src/main/native/cpp/json_pointer.cpp
@@ -36,7 +36,9 @@ SOFTWARE.
 
 #include <numeric> // accumulate
 
+#include "fmt/format.h"
 #include "wpi/SmallString.h"
+#include "wpi/StringExtras.h"
 
 namespace wpi {
 
@@ -50,17 +52,16 @@ std::string json_pointer::to_string() const noexcept
     });
 }
 
-int json_pointer::array_index(const Twine& s)
+int json_pointer::array_index(std::string_view s)
 {
-    SmallString<128> buf;
-    StringRef str = s.toNullTerminatedStringRef(buf);
+    SmallString<128> str{s};
     std::size_t processed_chars = 0;
-    const int res = std::stoi(str, &processed_chars);
+    const int res = std::stoi(str.c_str(), &processed_chars);
 
     // check if the string was completely read
     if (JSON_UNLIKELY(processed_chars != str.size()))
     {
-        JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + Twine(s) + "'"));
+        JSON_THROW(detail::out_of_range::create(404, fmt::format("unresolved reference token '{}'", s)));
     }
 
     return res;
@@ -108,7 +109,7 @@ json& json_pointer::get_and_create(json& j) const
                 }
                 JSON_CATCH(std::invalid_argument&)
                 {
-                    JSON_THROW(detail::parse_error::create(109, 0, "array index '" + Twine(reference_token) + "' is not a number"));
+                    JSON_THROW(detail::parse_error::create(109, 0, fmt::format("array index '{}' is not a number", reference_token)));
                 }
                 break;
             }
@@ -164,8 +165,7 @@ json& json_pointer::get_unchecked(json* ptr) const
                 if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0'))
                 {
                     JSON_THROW(detail::parse_error::create(106, 0,
-                                                           "array index '" + Twine(reference_token) +
-                                                           "' must not begin with '0'"));
+                        fmt::format("array index '{}' must not begin with '0'", reference_token)));
                 }
 
                 if (reference_token == "-")
@@ -183,14 +183,16 @@ json& json_pointer::get_unchecked(json* ptr) const
                     }
                     JSON_CATCH(std::invalid_argument&)
                     {
-                        JSON_THROW(detail::parse_error::create(109, 0, "array index '" + Twine(reference_token) + "' is not a number"));
+                        JSON_THROW(detail::parse_error::create(109, 0,
+                            fmt::format("array index '{}' is not a number", reference_token)));
                     }
                 }
                 break;
             }
 
             default:
-                JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + Twine(reference_token) + "'"));
+                JSON_THROW(detail::out_of_range::create(404,
+                    fmt::format("unresolved reference token '{}'", reference_token)));
         }
     }
 
@@ -217,16 +219,14 @@ json& json_pointer::get_checked(json* ptr) const
                 {
                     // "-" always fails the range check
                     JSON_THROW(detail::out_of_range::create(402,
-                                                            "array index '-' (" + Twine(ptr->m_value.array->size()) +
-                                                            ") is out of range"));
+                        fmt::format("array index '-' ({}) is out of range", ptr->m_value.array->size())));
                 }
 
                 // error condition (cf. RFC 6901, Sect. 4)
                 if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0'))
                 {
                     JSON_THROW(detail::parse_error::create(106, 0,
-                                                           "array index '" + Twine(reference_token) +
-                                                           "' must not begin with '0'"));
+                        fmt::format("array index '{}' must not begin with '0'", reference_token)));
                 }
 
                 // note: at performs range check
@@ -236,13 +236,15 @@ json& json_pointer::get_checked(json* ptr) const
                 }
                 JSON_CATCH(std::invalid_argument&)
                 {
-                    JSON_THROW(detail::parse_error::create(109, 0, "array index '" + Twine(reference_token) + "' is not a number"));
+                    JSON_THROW(detail::parse_error::create(109, 0,
+                        fmt::format("array index '{}' is not a number", reference_token)));
                 }
                 break;
             }
 
             default:
-                JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + Twine(reference_token) + "'"));
+                JSON_THROW(detail::out_of_range::create(404,
+                    fmt::format("unresolved reference token '{}'", reference_token)));
         }
     }
 
@@ -269,16 +271,14 @@ const json& json_pointer::get_unchecked(const json* ptr) const
                 {
                     // "-" cannot be used for const access
                     JSON_THROW(detail::out_of_range::create(402,
-                                                            "array index '-' (" + Twine(ptr->m_value.array->size()) +
-                                                            ") is out of range"));
+                        fmt::format("array index '-' ({}) is out of range", ptr->m_value.array->size())));
                 }
 
                 // error condition (cf. RFC 6901, Sect. 4)
                 if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0'))
                 {
                     JSON_THROW(detail::parse_error::create(106, 0,
-                                                           "array index '" + Twine(reference_token) +
-                                                           "' must not begin with '0'"));
+                        fmt::format("array index '{}' must not begin with '0'", reference_token)));
                 }
 
                 // use unchecked array access
@@ -289,13 +289,15 @@ const json& json_pointer::get_unchecked(const json* ptr) const
                 }
                 JSON_CATCH(std::invalid_argument&)
                 {
-                    JSON_THROW(detail::parse_error::create(109, 0, "array index '" + Twine(reference_token) + "' is not a number"));
+                    JSON_THROW(detail::parse_error::create(109, 0,
+                        fmt::format("array index '{}' is not a number", reference_token)));
                 }
                 break;
             }
 
             default:
-                JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + Twine(reference_token) + "'"));
+                JSON_THROW(detail::out_of_range::create(404,
+                    fmt::format("unresolved reference token '{}'", reference_token)));
         }
     }
 
@@ -322,16 +324,14 @@ const json& json_pointer::get_checked(const json* ptr) const
                 {
                     // "-" always fails the range check
                     JSON_THROW(detail::out_of_range::create(402,
-                                                            "array index '-' (" + Twine(ptr->m_value.array->size()) +
-                                                            ") is out of range"));
+                        fmt::format("array index '-' ({}) is out of range", ptr->m_value.array->size())));
                 }
 
                 // error condition (cf. RFC 6901, Sect. 4)
                 if (JSON_UNLIKELY(reference_token.size() > 1 and reference_token[0] == '0'))
                 {
                     JSON_THROW(detail::parse_error::create(106, 0,
-                                                           "array index '" + Twine(reference_token) +
-                                                           "' must not begin with '0'"));
+                        fmt::format("array index '{}' must not begin with '0'", reference_token)));
                 }
 
                 // note: at performs range check
@@ -341,23 +341,23 @@ const json& json_pointer::get_checked(const json* ptr) const
                 }
                 JSON_CATCH(std::invalid_argument&)
                 {
-                    JSON_THROW(detail::parse_error::create(109, 0, "array index '" + Twine(reference_token) + "' is not a number"));
+                    JSON_THROW(detail::parse_error::create(109, 0,
+                        fmt::format("array index '{}' is not a number", reference_token)));
                 }
                 break;
             }
 
             default:
-                JSON_THROW(detail::out_of_range::create(404, "unresolved reference token '" + Twine(reference_token) + "'"));
+                JSON_THROW(detail::out_of_range::create(404,
+                    fmt::format("unresolved reference token '{}'", reference_token)));
         }
     }
 
     return *ptr;
 }
 
-std::vector<std::string> json_pointer::split(const Twine& reference_string)
+std::vector<std::string> json_pointer::split(std::string_view ref_str)
 {
-    SmallString<128> ref_str_buf;
-    StringRef ref_str = reference_string.toStringRef(ref_str_buf);
     std::vector<std::string> result;
 
     // special case: empty reference string -> no reference tokens
@@ -370,8 +370,7 @@ std::vector<std::string> json_pointer::split(const Twine& reference_string)
     if (JSON_UNLIKELY(ref_str[0] != '/'))
     {
         JSON_THROW(detail::parse_error::create(107, 1,
-                                               "JSON pointer must be empty or begin with '/' - was: '" +
-                                               Twine(ref_str) + "'"));
+            fmt::format("JSON pointer must be empty or begin with '/' - was: '{}'", ref_str)));
     }
 
     // extract the reference tokens:
@@ -392,11 +391,11 @@ std::vector<std::string> json_pointer::split(const Twine& reference_string)
     {
         // use the text between the beginning of the reference token
         // (start) and the last slash (slash).
-        auto reference_token = ref_str.slice(start, slash);
+        auto reference_token = slice(ref_str, start, slash);
 
         // check reference tokens are properly escaped
         for (std::size_t pos = reference_token.find_first_of('~');
-                pos != StringRef::npos;
+                pos != std::string_view::npos;
                 pos = reference_token.find_first_of('~', pos + 1))
         {
             assert(reference_token[pos] == '~');
@@ -411,7 +410,7 @@ std::vector<std::string> json_pointer::split(const Twine& reference_string)
         }
 
         // finally, store the reference token
-        std::string ref_tok = reference_token;
+        std::string ref_tok{reference_token};
         unescape(ref_tok);
         result.emplace_back(std::move(ref_tok));
     }
@@ -444,7 +443,7 @@ void json_pointer::unescape(std::string& s)
     replace_substring(s, "~0", "~");
 }
 
-void json_pointer::flatten(const Twine& reference_string,
+void json_pointer::flatten(std::string_view reference_string,
                     const json& value,
                     json& result)
 {
@@ -455,15 +454,14 @@ void json_pointer::flatten(const Twine& reference_string,
             if (value.m_value.array->empty())
             {
                 // flatten empty array as null
-                SmallString<64> buf;
-                result[reference_string.toStringRef(buf)] = nullptr;
+                result[reference_string] = nullptr;
             }
             else
             {
                 // iterate array and use index as reference string
                 for (std::size_t i = 0; i < value.m_value.array->size(); ++i)
                 {
-                    flatten(reference_string + "/" + Twine(i),
+                    flatten(fmt::format("{}/{}", reference_string, i),
                             value.m_value.array->operator[](i), result);
                 }
             }
@@ -475,15 +473,14 @@ void json_pointer::flatten(const Twine& reference_string,
             if (value.m_value.object->empty())
             {
                 // flatten empty object as null
-                SmallString<64> buf;
-                result[reference_string.toStringRef(buf)] = nullptr;
+                result[reference_string] = nullptr;
             }
             else
             {
                 // iterate object and use keys as reference string
                 for (const auto& element : *value.m_value.object)
                 {
-                    flatten(reference_string + "/" + Twine(escape(element.first())), element.second, result);
+                    flatten(fmt::format("{}/{}", reference_string, escape(std::string{element.first()})), element.second, result);
                 }
             }
             break;
@@ -492,8 +489,7 @@ void json_pointer::flatten(const Twine& reference_string,
         default:
         {
             // add primitive value with its reference string
-            SmallString<64> buf;
-            result[reference_string.toStringRef(buf)] = value;
+            result[reference_string] = value;
             break;
         }
     }
diff --git a/wpiutil/src/main/native/cpp/json_serializer.cpp b/wpiutil/src/main/native/cpp/json_serializer.cpp
index 8ab92b12cc..4f71bc817e 100644
--- a/wpiutil/src/main/native/cpp/json_serializer.cpp
+++ b/wpiutil/src/main/native/cpp/json_serializer.cpp
@@ -34,9 +34,8 @@ SOFTWARE.
 #define WPI_JSON_IMPLEMENTATION
 #include "wpi/json.h"
 
-#include "wpi/Format.h"
+#include "fmt/format.h"
 #include "wpi/SmallString.h"
-#include "wpi/StringExtras.h"
 #include "wpi/raw_os_ostream.h"
 
 #include "json_serializer.h"
@@ -1332,7 +1331,7 @@ void json::serializer::dump(const json& val, const bool pretty_print,
     }
 }
 
-void json::serializer::dump_escaped(StringRef s, const bool ensure_ascii)
+void json::serializer::dump_escaped(std::string_view s, const bool ensure_ascii)
 {
     uint32_t codepoint;
     uint8_t state = UTF8_ACCEPT;
@@ -1397,12 +1396,12 @@ void json::serializer::dump_escaped(StringRef s, const bool ensure_ascii)
                         {
                             if (codepoint <= 0xFFFF)
                             {
-                                o << '\\' << 'u' << format_hex_no_prefix(codepoint, 4);
+                                o << fmt::format("\\u{:04x}", codepoint);
                             }
                             else
                             {
-                                o << '\\' << 'u' << format_hex_no_prefix(0xD7C0 + (codepoint >> 10), 4);
-                                o << '\\' << 'u' << format_hex_no_prefix(0xDC00 + (codepoint & 0x3FF), 4);
+                                o << fmt::format("\\u{:04x}", 0xD7C0 + (codepoint >> 10));
+                                o << fmt::format("\\u{:04x}", 0xDC00 + (codepoint & 0x3FF));
                             }
                         }
                         else
@@ -1419,7 +1418,7 @@ void json::serializer::dump_escaped(StringRef s, const bool ensure_ascii)
 
             case UTF8_REJECT:  // decode found invalid UTF-8 byte
             {
-                JSON_THROW(type_error::create(316, "invalid UTF-8 byte at index " + Twine(i) + ": 0x" + Twine::utohexstr(byte)));
+                JSON_THROW(type_error::create(316, fmt::format("invalid UTF-8 byte at index {}: {:#02x}", i, byte)));
             }
 
             default:  // decode found yet incomplete multi-byte code point
@@ -1437,7 +1436,7 @@ void json::serializer::dump_escaped(StringRef s, const bool ensure_ascii)
     if (JSON_UNLIKELY(state != UTF8_ACCEPT))
     {
         // we finish reading, but do not accept: string was incomplete
-        JSON_THROW(type_error::create(316, "incomplete UTF-8 string; last byte: 0x" + Twine::utohexstr(static_cast<uint8_t>(s.back()))));
+        JSON_THROW(type_error::create(316, fmt::format("incomplete UTF-8 string; last byte: {:#02x}", s.back())));
     }
 }
 
diff --git a/wpiutil/src/main/native/cpp/json_serializer.h b/wpiutil/src/main/native/cpp/json_serializer.h
index 6c5ffbe477..35907a24a9 100644
--- a/wpiutil/src/main/native/cpp/json_serializer.h
+++ b/wpiutil/src/main/native/cpp/json_serializer.h
@@ -98,7 +98,7 @@ class json::serializer
 
     @complexity Linear in the length of string @a s.
     */
-    void dump_escaped(StringRef s, const bool ensure_ascii);
+    void dump_escaped(std::string_view s, const bool ensure_ascii);
 
     template <typename NumberType,
               detail::enable_if_t<std::is_same_v<NumberType, uint64_t>, int> = 0>
diff --git a/wpiutil/src/main/native/cpp/llvm/ConvertUTF.cpp b/wpiutil/src/main/native/cpp/llvm/ConvertUTF.cpp
index 2594d9a8de..3050e631f2 100644
--- a/wpiutil/src/main/native/cpp/llvm/ConvertUTF.cpp
+++ b/wpiutil/src/main/native/cpp/llvm/ConvertUTF.cpp
@@ -744,10 +744,10 @@ ConversionResult ConvertUTF8toUTF32(const UTF8 **sourceStart,
 namespace sys {
 namespace windows {
 std::error_code CodePageToUTF16(unsigned codepage,
-                                wpi::StringRef original,
+                                std::string_view original,
                                 wpi::SmallVectorImpl<wchar_t> &utf16) {
   if (!original.empty()) {
-    int len = ::MultiByteToWideChar(codepage, MB_ERR_INVALID_CHARS, original.begin(),
+    int len = ::MultiByteToWideChar(codepage, MB_ERR_INVALID_CHARS, original.data(),
                                     original.size(), utf16.begin(), 0);
 
     if (len == 0) {
@@ -757,7 +757,7 @@ std::error_code CodePageToUTF16(unsigned codepage,
     utf16.reserve(len + 1);
     utf16.set_size(len);
 
-    len = ::MultiByteToWideChar(codepage, MB_ERR_INVALID_CHARS, original.begin(),
+    len = ::MultiByteToWideChar(codepage, MB_ERR_INVALID_CHARS, original.data(),
                                 original.size(), utf16.begin(), utf16.size());
 
     if (len == 0) {
@@ -772,12 +772,12 @@ std::error_code CodePageToUTF16(unsigned codepage,
   return std::error_code();
 }
 
-std::error_code UTF8ToUTF16(wpi::StringRef utf8,
+std::error_code UTF8ToUTF16(std::string_view utf8,
                             wpi::SmallVectorImpl<wchar_t> &utf16) {
   return CodePageToUTF16(CP_UTF8, utf8, utf16);
 }
 
-std::error_code CurCPToUTF16(wpi::StringRef curcp,
+std::error_code CurCPToUTF16(std::string_view curcp,
                             wpi::SmallVectorImpl<wchar_t> &utf16) {
   return CodePageToUTF16(CP_ACP, curcp, utf16);
 }
diff --git a/wpiutil/src/main/native/cpp/llvm/ConvertUTFWrapper.cpp b/wpiutil/src/main/native/cpp/llvm/ConvertUTFWrapper.cpp
index 3402988d4e..bf9b1ad745 100644
--- a/wpiutil/src/main/native/cpp/llvm/ConvertUTFWrapper.cpp
+++ b/wpiutil/src/main/native/cpp/llvm/ConvertUTFWrapper.cpp
@@ -80,7 +80,7 @@ bool convertUTF16ToUTF8String(ArrayRef<UTF16> SrcUTF16,
   return true;
 }
 
-bool convertUTF8ToUTF16String(StringRef SrcUTF8,
+bool convertUTF8ToUTF16String(std::string_view SrcUTF8,
                               SmallVectorImpl<UTF16> &DstUTF16) {
   assert(DstUTF16.empty());
 
@@ -91,8 +91,8 @@ bool convertUTF8ToUTF16String(StringRef SrcUTF8,
     return true;
   }
 
-  const UTF8 *Src = reinterpret_cast<const UTF8 *>(SrcUTF8.begin());
-  const UTF8 *SrcEnd = reinterpret_cast<const UTF8 *>(SrcUTF8.end());
+  const UTF8 *Src = reinterpret_cast<const UTF8 *>(SrcUTF8.data());
+  const UTF8 *SrcEnd = reinterpret_cast<const UTF8 *>(SrcUTF8.data() + SrcUTF8.size());
 
   // Allocate the same number of UTF-16 code units as UTF-8 code units. Encoding
   // as UTF-16 should always require the same amount or less code units than the
diff --git a/wpiutil/src/main/native/cpp/llvm/Error.cpp b/wpiutil/src/main/native/cpp/llvm/Error.cpp
deleted file mode 100644
index 7bf9c5f4de..0000000000
--- a/wpiutil/src/main/native/cpp/llvm/Error.cpp
+++ /dev/null
@@ -1,138 +0,0 @@
-//===----- lib/Support/Error.cpp - Error and associated utilities ---------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#include "wpi/Error.h"
-#include "wpi/Twine.h"
-#include "wpi/ErrorHandling.h"
-#include "wpi/ManagedStatic.h"
-#include <system_error>
-
-using namespace wpi;
-
-namespace {
-
-  enum class ErrorErrorCode : int {
-    MultipleErrors = 1,
-    FileError,
-    InconvertibleError
-  };
-
-  // FIXME: This class is only here to support the transition to wpi::Error. It
-  // will be removed once this transition is complete. Clients should prefer to
-  // deal with the Error value directly, rather than converting to error_code.
-  class ErrorErrorCategory : public std::error_category {
-  public:
-    const char *name() const noexcept override { return "Error"; }
-
-    std::string message(int condition) const override {
-      switch (static_cast<ErrorErrorCode>(condition)) {
-      case ErrorErrorCode::MultipleErrors:
-        return "Multiple errors";
-      case ErrorErrorCode::InconvertibleError:
-        return "Inconvertible error value. An error has occurred that could "
-               "not be converted to a known std::error_code. Please file a "
-               "bug.";
-      case ErrorErrorCode::FileError:
-          return "A file error occurred.";
-      }
-      wpi_unreachable("Unhandled error code");
-    }
-  };
-
-}
-
-static ManagedStatic<ErrorErrorCategory> ErrorErrorCat;
-
-namespace wpi {
-
-void ErrorInfoBase::anchor() {}
-char ErrorInfoBase::ID = 0;
-char ErrorList::ID = 0;
-void ECError::anchor() {}
-char ECError::ID = 0;
-char StringError::ID = 0;
-char FileError::ID = 0;
-
-void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner) {
-  if (!E)
-    return;
-  OS << ErrorBanner;
-  handleAllErrors(std::move(E), [&](const ErrorInfoBase &EI) {
-    EI.log(OS);
-    OS << "\n";
-  });
-}
-
-
-std::error_code ErrorList::convertToErrorCode() const {
-  return std::error_code(static_cast<int>(ErrorErrorCode::MultipleErrors),
-                         *ErrorErrorCat);
-}
-
-std::error_code inconvertibleErrorCode() {
-  return std::error_code(static_cast<int>(ErrorErrorCode::InconvertibleError),
-                         *ErrorErrorCat);
-}
-
-std::error_code FileError::convertToErrorCode() const {
-  return std::error_code(static_cast<int>(ErrorErrorCode::FileError),
-                         *ErrorErrorCat);
-}
-
-Error errorCodeToError(std::error_code EC) {
-  if (!EC)
-    return Error::success();
-  return Error(std::make_unique<ECError>(ECError(EC)));
-}
-
-std::error_code errorToErrorCode(Error Err) {
-  std::error_code EC;
-  handleAllErrors(std::move(Err), [&](const ErrorInfoBase &EI) {
-    EC = EI.convertToErrorCode();
-  });
-  if (EC == inconvertibleErrorCode())
-    report_fatal_error(EC.message());
-  return EC;
-}
-
-StringError::StringError(std::error_code EC, const Twine &S)
-    : Msg(S.str()), EC(EC) {}
-
-StringError::StringError(const Twine &S, std::error_code EC)
-    : Msg(S.str()), EC(EC), PrintMsgOnly(true) {}
-
-void StringError::log(raw_ostream &OS) const {
-  if (PrintMsgOnly) {
-    OS << Msg;
-  } else {
-    OS << EC.message();
-    if (!Msg.empty())
-      OS << (" " + Msg);
-  }
-}
-
-std::error_code StringError::convertToErrorCode() const {
-  return EC;
-}
-
-Error createStringError(std::error_code EC, char const *Msg) {
-  return make_error<StringError>(Msg, EC);
-}
-
-void report_fatal_error(Error Err, bool GenCrashDiag) {
-  assert(Err && "report_fatal_error called with success value");
-  std::string ErrMsg;
-  {
-    raw_string_ostream ErrStream(ErrMsg);
-    logAllUnhandledErrors(std::move(Err), ErrStream);
-  }
-  report_fatal_error(ErrMsg);
-}
-
-} // end namespace wpi
diff --git a/wpiutil/src/main/native/cpp/llvm/ErrorHandling.cpp b/wpiutil/src/main/native/cpp/llvm/ErrorHandling.cpp
index ef79456779..8e522c4193 100644
--- a/wpiutil/src/main/native/cpp/llvm/ErrorHandling.cpp
+++ b/wpiutil/src/main/native/cpp/llvm/ErrorHandling.cpp
@@ -14,11 +14,10 @@
 
 #include "wpi/ErrorHandling.h"
 #include "wpi/SmallVector.h"
-#include "wpi/Twine.h"
-#include "wpi/Error.h"
 #include "wpi/WindowsError.h"
-#include "wpi/raw_ostream.h"
+#include "fmt/format.h"
 #include <cassert>
+#include <cstdio>
 #include <cstdlib>
 #include <mutex>
 #include <new>
@@ -68,18 +67,14 @@ void wpi::remove_fatal_error_handler() {
 }
 
 void wpi::report_fatal_error(const char *Reason, bool GenCrashDiag) {
-  report_fatal_error(Twine(Reason), GenCrashDiag);
+  report_fatal_error(std::string_view(Reason), GenCrashDiag);
 }
 
 void wpi::report_fatal_error(const std::string &Reason, bool GenCrashDiag) {
-  report_fatal_error(Twine(Reason), GenCrashDiag);
+  report_fatal_error(std::string_view(Reason), GenCrashDiag);
 }
 
-void wpi::report_fatal_error(StringRef Reason, bool GenCrashDiag) {
-  report_fatal_error(Twine(Reason), GenCrashDiag);
-}
-
-void wpi::report_fatal_error(const Twine &Reason, bool GenCrashDiag) {
+void wpi::report_fatal_error(std::string_view Reason, bool GenCrashDiag) {
   wpi::fatal_error_handler_t handler = nullptr;
   void* handlerData = nullptr;
   {
@@ -91,21 +86,9 @@ void wpi::report_fatal_error(const Twine &Reason, bool GenCrashDiag) {
   }
 
   if (handler) {
-    handler(handlerData, Reason.str(), GenCrashDiag);
+    handler(handlerData, std::string{Reason}, GenCrashDiag);
   } else {
-    // Blast the result out to stderr.  We don't try hard to make sure this
-    // succeeds (e.g. handling EINTR) and we can't use errs() here because
-    // raw ostreams can call report_fatal_error.
-    SmallVector<char, 64> Buffer;
-    raw_svector_ostream OS(Buffer);
-    OS << "LLVM ERROR: " << Reason << "\n";
-    StringRef MessageStr = OS.str();
-#ifdef _WIN32
-    int written = ::_write(2, MessageStr.data(), MessageStr.size());
-#else
-    ssize_t written = ::write(2, MessageStr.data(), MessageStr.size());
-#endif
-    (void)written; // If something went wrong, we deliberately just give up.
+    fmt::print(stderr, "LLVM ERROR: {}\n");
   }
 
   exit(1);
@@ -185,11 +168,11 @@ void wpi::wpi_unreachable_internal(const char *msg, const char *file,
   // wpi_unreachable is intended to be used to indicate "impossible"
   // situations, and not legitimate runtime errors.
   if (msg)
-    errs() << msg << "\n";
-  errs() << "UNREACHABLE executed";
+    fmt::print(stderr, "{}\n", msg);
+  std::fputs("UNREACHABLE executed", stderr);
   if (file)
-    errs() << " at " << file << ":" << line;
-  errs() << "!\n";
+    fmt::print(stderr, " at {}:{}", file, line);
+  fmt::print(stderr, "{}", "!\n");
   abort();
 #ifdef LLVM_BUILTIN_UNREACHABLE
   // Windows systems and possibly others don't declare abort() to be noreturn,
diff --git a/wpiutil/src/main/native/cpp/llvm/NativeFormatting.cpp b/wpiutil/src/main/native/cpp/llvm/NativeFormatting.cpp
deleted file mode 100644
index 985e269d58..0000000000
--- a/wpiutil/src/main/native/cpp/llvm/NativeFormatting.cpp
+++ /dev/null
@@ -1,264 +0,0 @@
-//===- NativeFormatting.cpp - Low level formatting helpers -------*- C++-*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#include "wpi/NativeFormatting.h"
-
-#include "wpi/ArrayRef.h"
-#include "wpi/SmallString.h"
-#include "wpi/StringExtras.h"
-#include "wpi/Format.h"
-
-#include <float.h>
-
-using namespace wpi;
-
-template<typename T, std::size_t N>
-static int format_to_buffer(T Value, char (&Buffer)[N]) {
-  char *EndPtr = std::end(Buffer);
-  char *CurPtr = EndPtr;
-
-  do {
-    *--CurPtr = '0' + char(Value % 10);
-    Value /= 10;
-  } while (Value);
-  return EndPtr - CurPtr;
-}
-
-static void writeWithCommas(raw_ostream &S, ArrayRef<char> Buffer) {
-  assert(!Buffer.empty());
-
-  ArrayRef<char> ThisGroup;
-  int InitialDigits = ((Buffer.size() - 1) % 3) + 1;
-  ThisGroup = Buffer.take_front(InitialDigits);
-  S.write(ThisGroup.data(), ThisGroup.size());
-
-  Buffer = Buffer.drop_front(InitialDigits);
-  assert(Buffer.size() % 3 == 0);
-  while (!Buffer.empty()) {
-    S << ',';
-    ThisGroup = Buffer.take_front(3);
-    S.write(ThisGroup.data(), 3);
-    Buffer = Buffer.drop_front(3);
-  }
-}
-
-template <typename T>
-static void write_unsigned_impl(raw_ostream &S, T N, size_t MinDigits,
-                                IntegerStyle Style, bool IsNegative) {
-  static_assert(std::is_unsigned<T>::value, "Value is not unsigned!");
-
-  char NumberBuffer[128];
-  std::memset(NumberBuffer, '0', sizeof(NumberBuffer));
-
-  size_t Len = 0;
-  Len = format_to_buffer(N, NumberBuffer);
-
-  if (IsNegative)
-    S << '-';
-
-  if (Len < MinDigits && Style != IntegerStyle::Number) {
-    for (size_t I = Len; I < MinDigits; ++I)
-      S << '0';
-  }
-
-  if (Style == IntegerStyle::Number) {
-    writeWithCommas(S, ArrayRef<char>(std::end(NumberBuffer) - Len, Len));
-  } else {
-    S.write(std::end(NumberBuffer) - Len, Len);
-  }
-}
-
-template <typename T>
-static void write_unsigned(raw_ostream &S, T N, size_t MinDigits,
-                           IntegerStyle Style, bool IsNegative = false) {
-  // Output using 32-bit div/mod if possible.
-  if (N == static_cast<uint32_t>(N))
-    write_unsigned_impl(S, static_cast<uint32_t>(N), MinDigits, Style,
-                        IsNegative);
-  else
-    write_unsigned_impl(S, N, MinDigits, Style, IsNegative);
-}
-
-template <typename T>
-static void write_signed(raw_ostream &S, T N, size_t MinDigits,
-                         IntegerStyle Style) {
-  static_assert(std::is_signed<T>::value, "Value is not signed!");
-
-  using UnsignedT = typename std::make_unsigned<T>::type;
-
-  if (N >= 0) {
-    write_unsigned(S, static_cast<UnsignedT>(N), MinDigits, Style);
-    return;
-  }
-
-  UnsignedT UN = -(UnsignedT)N;
-  write_unsigned(S, UN, MinDigits, Style, true);
-}
-
-void wpi::write_integer(raw_ostream &S, unsigned int N, size_t MinDigits,
-                         IntegerStyle Style) {
-  write_unsigned(S, N, MinDigits, Style);
-}
-
-void wpi::write_integer(raw_ostream &S, int N, size_t MinDigits,
-                         IntegerStyle Style) {
-  write_signed(S, N, MinDigits, Style);
-}
-
-void wpi::write_integer(raw_ostream &S, unsigned long N, size_t MinDigits,
-                         IntegerStyle Style) {
-  write_unsigned(S, N, MinDigits, Style);
-}
-
-void wpi::write_integer(raw_ostream &S, long N, size_t MinDigits,
-                         IntegerStyle Style) {
-  write_signed(S, N, MinDigits, Style);
-}
-
-void wpi::write_integer(raw_ostream &S, unsigned long long N, size_t MinDigits,
-                         IntegerStyle Style) {
-  write_unsigned(S, N, MinDigits, Style);
-}
-
-void wpi::write_integer(raw_ostream &S, long long N, size_t MinDigits,
-                         IntegerStyle Style) {
-  write_signed(S, N, MinDigits, Style);
-}
-
-void wpi::write_hex(raw_ostream &S, uint64_t N, HexPrintStyle Style,
-                     std::optional<size_t> Width) {
-  const size_t kMaxWidth = 128u;
-
-  size_t W = std::min(kMaxWidth, Width.value_or(0u));
-
-  unsigned Nibbles = (64 - countLeadingZeros(N) + 3) / 4;
-  bool Prefix = (Style == HexPrintStyle::PrefixLower ||
-                 Style == HexPrintStyle::PrefixUpper);
-  bool Upper =
-      (Style == HexPrintStyle::Upper || Style == HexPrintStyle::PrefixUpper);
-  unsigned PrefixChars = Prefix ? 2 : 0;
-  unsigned NumChars =
-      std::max(static_cast<unsigned>(W), std::max(1u, Nibbles) + PrefixChars);
-
-  char NumberBuffer[kMaxWidth];
-  ::memset(NumberBuffer, '0', wpi::array_lengthof(NumberBuffer));
-  if (Prefix)
-    NumberBuffer[1] = 'x';
-  char *EndPtr = NumberBuffer + NumChars;
-  char *CurPtr = EndPtr;
-  while (N) {
-    unsigned char x = static_cast<unsigned char>(N) % 16;
-    *--CurPtr = hexdigit(x, !Upper);
-    N /= 16;
-  }
-
-  S.write(NumberBuffer, NumChars);
-}
-
-void wpi::write_double(raw_ostream &S, double N, FloatStyle Style,
-                        std::optional<size_t> Precision) {
-  size_t Prec = Precision.value_or(getDefaultPrecision(Style));
-
-  if (std::isnan(N)) {
-    S << "nan";
-    return;
-  } else if (std::isinf(N)) {
-    S << "INF";
-    return;
-  }
-
-  char Letter;
-  if (Style == FloatStyle::Exponent)
-    Letter = 'e';
-  else if (Style == FloatStyle::ExponentUpper)
-    Letter = 'E';
-  else
-    Letter = 'f';
-
-  SmallString<8> Spec;
-  wpi::raw_svector_ostream Out(Spec);
-  Out << "%." << Prec << Letter;
-
-  if (Style == FloatStyle::Exponent || Style == FloatStyle::ExponentUpper) {
-#ifdef _WIN32
-// On MSVCRT and compatible, output of %e is incompatible to Posix
-// by default. Number of exponent digits should be at least 2. "%+03d"
-// FIXME: Implement our formatter to here or Support/Format.h!
-#if defined(__MINGW32__)
-    // FIXME: It should be generic to C++11.
-    if (N == 0.0 && std::signbit(N)) {
-      char NegativeZero[] = "-0.000000e+00";
-      if (Style == FloatStyle::ExponentUpper)
-        NegativeZero[strlen(NegativeZero) - 4] = 'E';
-      S << NegativeZero;
-      return;
-    }
-#else
-    int fpcl = _fpclass(N);
-
-    // negative zero
-    if (fpcl == _FPCLASS_NZ) {
-      char NegativeZero[] = "-0.000000e+00";
-      if (Style == FloatStyle::ExponentUpper)
-        NegativeZero[strlen(NegativeZero) - 4] = 'E';
-      S << NegativeZero;
-      return;
-    }
-#endif
-
-    char buf[32];
-    unsigned len;
-    len = format(Spec.c_str(), N).snprint(buf, sizeof(buf));
-    if (len <= sizeof(buf) - 2) {
-      if (len >= 5 && (buf[len - 5] == 'e' || buf[len - 5] == 'E') &&
-          buf[len - 3] == '0') {
-        int cs = buf[len - 4];
-        if (cs == '+' || cs == '-') {
-          int c1 = buf[len - 2];
-          int c0 = buf[len - 1];
-          if (isdigit(static_cast<unsigned char>(c1)) &&
-              isdigit(static_cast<unsigned char>(c0))) {
-            // Trim leading '0': "...e+012" -> "...e+12\0"
-            buf[len - 3] = c1;
-            buf[len - 2] = c0;
-            buf[--len] = 0;
-          }
-        }
-      }
-      S << buf;
-      return;
-    }
-#endif
-  }
-
-  if (Style == FloatStyle::Percent)
-    N *= 100.0;
-
-  char Buf[32];
-  format(Spec.c_str(), N).snprint(Buf, sizeof(Buf));
-  S << Buf;
-  if (Style == FloatStyle::Percent)
-    S << '%';
-}
-
-bool wpi::isPrefixedHexStyle(HexPrintStyle S) {
-  return (S == HexPrintStyle::PrefixLower || S == HexPrintStyle::PrefixUpper);
-}
-
-size_t wpi::getDefaultPrecision(FloatStyle Style) {
-  switch (Style) {
-  case FloatStyle::Exponent:
-  case FloatStyle::ExponentUpper:
-    return 6; // Number of decimal places.
-  case FloatStyle::Fixed:
-  case FloatStyle::Percent:
-    return 2; // Number of decimal places.
-  }
-  LLVM_BUILTIN_UNREACHABLE;
-}
diff --git a/wpiutil/src/main/native/cpp/llvm/StringMap.cpp b/wpiutil/src/main/native/cpp/llvm/StringMap.cpp
index f89a8aebea..768801d848 100644
--- a/wpiutil/src/main/native/cpp/llvm/StringMap.cpp
+++ b/wpiutil/src/main/native/cpp/llvm/StringMap.cpp
@@ -89,7 +89,7 @@ void StringMapImpl::init(unsigned InitSize) {
 /// specified bucket will be non-null.  Otherwise, it will be null.  In either
 /// case, the FullHashValue field of the bucket will be set to the hash value
 /// of the string.
-unsigned StringMapImpl::LookupBucketFor(StringRef Name) {
+unsigned StringMapImpl::LookupBucketFor(std::string_view Name) {
   unsigned HTSize = NumBuckets;
   if (HTSize == 0) {  // Hash table unallocated so far?
     init(16);
@@ -128,7 +128,7 @@ unsigned StringMapImpl::LookupBucketFor(StringRef Name) {
       // Do the comparison like this because Name isn't necessarily
       // null-terminated!
       char *ItemStr = (char*)BucketItem+ItemSize;
-      if (Name == StringRef(ItemStr, BucketItem->getKeyLength())) {
+      if (Name == std::string_view(ItemStr, BucketItem->getKeyLength())) {
         // We found a match!
         return BucketNo;
       }
@@ -146,7 +146,7 @@ unsigned StringMapImpl::LookupBucketFor(StringRef Name) {
 /// FindKey - Look up the bucket that contains the specified key. If it exists
 /// in the map, return the bucket number of the key.  Otherwise return -1.
 /// This does not modify the map.
-int StringMapImpl::FindKey(StringRef Key) const {
+int StringMapImpl::FindKey(std::string_view Key) const {
   unsigned HTSize = NumBuckets;
   if (HTSize == 0) return -1;  // Really empty table?
   unsigned FullHashValue = HashString(Key);
@@ -171,7 +171,7 @@ int StringMapImpl::FindKey(StringRef Key) const {
       // Do the comparison like this because NameStart isn't necessarily
       // null-terminated!
       char *ItemStr = (char*)BucketItem+ItemSize;
-      if (Key == StringRef(ItemStr, BucketItem->getKeyLength())) {
+      if (Key == std::string_view(ItemStr, BucketItem->getKeyLength())) {
         // We found a match!
         return BucketNo;
       }
@@ -190,14 +190,14 @@ int StringMapImpl::FindKey(StringRef Key) const {
 /// delete it.  This aborts if the value isn't in the table.
 void StringMapImpl::RemoveKey(StringMapEntryBase *V) {
   const char *VStr = (char*)V + ItemSize;
-  StringMapEntryBase *V2 = RemoveKey(StringRef(VStr, V->getKeyLength()));
+  StringMapEntryBase *V2 = RemoveKey(std::string_view(VStr, V->getKeyLength()));
   (void)V2;
   assert(V == V2 && "Didn't find key?");
 }
 
 /// RemoveKey - Remove the StringMapEntry for the specified key from the
 /// table, returning it.  If the key is not in the table, this returns null.
-StringMapEntryBase *StringMapImpl::RemoveKey(StringRef Key) {
+StringMapEntryBase *StringMapImpl::RemoveKey(std::string_view Key) {
   int Bucket = FindKey(Key);
   if (Bucket == -1) return nullptr;
 
diff --git a/wpiutil/src/main/native/cpp/llvm/StringRef.cpp b/wpiutil/src/main/native/cpp/llvm/StringRef.cpp
deleted file mode 100644
index ea44bead79..0000000000
--- a/wpiutil/src/main/native/cpp/llvm/StringRef.cpp
+++ /dev/null
@@ -1,507 +0,0 @@
-//===-- StringRef.cpp - Lightweight String References ---------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#include "wpi/StringRef.h"
-#include "wpi/Hashing.h"
-#include "wpi/StringExtras.h"
-#include "wpi/SmallVector.h"
-#include <bitset>
-#include <climits>
-#include <ostream>
-
-using namespace wpi;
-
-// MSVC emits references to this into the translation units which reference it.
-#ifndef _MSC_VER
-const size_t StringRef::npos;
-#endif
-
-// strncasecmp() is not available on non-POSIX systems, so define an
-// alternative function here.
-static int ascii_strncasecmp(const char *LHS, const char *RHS, size_t Length) noexcept {
-  for (size_t I = 0; I < Length; ++I) {
-    unsigned char LHC = toLower(LHS[I]);
-    unsigned char RHC = toLower(RHS[I]);
-    if (LHC != RHC)
-      return LHC < RHC ? -1 : 1;
-  }
-  return 0;
-}
-
-/// compare_lower - Compare strings, ignoring case.
-int StringRef::compare_lower(StringRef RHS) const noexcept {
-  if (int Res = ascii_strncasecmp(Data, RHS.Data, std::min(Length, RHS.Length)))
-    return Res;
-  if (Length == RHS.Length)
-    return 0;
-  return Length < RHS.Length ? -1 : 1;
-}
-
-/// Check if this string starts with the given \p Prefix, ignoring case.
-bool StringRef::startswith_lower(StringRef Prefix) const noexcept {
-  return Length >= Prefix.Length &&
-      ascii_strncasecmp(Data, Prefix.Data, Prefix.Length) == 0;
-}
-
-/// Check if this string ends with the given \p Suffix, ignoring case.
-bool StringRef::endswith_lower(StringRef Suffix) const noexcept {
-  return Length >= Suffix.Length &&
-      ascii_strncasecmp(end() - Suffix.Length, Suffix.Data, Suffix.Length) == 0;
-}
-
-size_t StringRef::find_lower(char C, size_t From) const noexcept {
-  char L = toLower(C);
-  return find_if([L](char D) { return toLower(D) == L; }, From);
-}
-
-/// compare_numeric - Compare strings, handle embedded numbers.
-int StringRef::compare_numeric(StringRef RHS) const noexcept {
-  for (size_t I = 0, E = std::min(Length, RHS.Length); I != E; ++I) {
-    // Check for sequences of digits.
-    if (isDigit(Data[I]) && isDigit(RHS.Data[I])) {
-      // The longer sequence of numbers is considered larger.
-      // This doesn't really handle prefixed zeros well.
-      size_t J;
-      for (J = I + 1; J != E + 1; ++J) {
-        bool ld = J < Length && isDigit(Data[J]);
-        bool rd = J < RHS.Length && isDigit(RHS.Data[J]);
-        if (ld != rd)
-          return rd ? -1 : 1;
-        if (!rd)
-          break;
-      }
-      // The two number sequences have the same length (J-I), just memcmp them.
-      if (int Res = compareMemory(Data + I, RHS.Data + I, J - I))
-        return Res < 0 ? -1 : 1;
-      // Identical number sequences, continue search after the numbers.
-      I = J - 1;
-      continue;
-    }
-    if (Data[I] != RHS.Data[I])
-      return (unsigned char)Data[I] < (unsigned char)RHS.Data[I] ? -1 : 1;
-  }
-  if (Length == RHS.Length)
-    return 0;
-  return Length < RHS.Length ? -1 : 1;
-}
-
-//===----------------------------------------------------------------------===//
-// String Operations
-//===----------------------------------------------------------------------===//
-
-std::string StringRef::lower() const {
-  std::string Result(size(), char());
-  for (size_type i = 0, e = size(); i != e; ++i) {
-    Result[i] = toLower(Data[i]);
-  }
-  return Result;
-}
-
-std::string StringRef::upper() const {
-  std::string Result(size(), char());
-  for (size_type i = 0, e = size(); i != e; ++i) {
-    Result[i] = toUpper(Data[i]);
-  }
-  return Result;
-}
-
-//===----------------------------------------------------------------------===//
-// String Searching
-//===----------------------------------------------------------------------===//
-
-
-/// find - Search for the first string \arg Str in the string.
-///
-/// \return - The index of the first occurrence of \arg Str, or npos if not
-/// found.
-size_t StringRef::find(StringRef Str, size_t From) const noexcept {
-  if (From > Length)
-    return npos;
-
-  const char *Start = Data + From;
-  size_t Size = Length - From;
-
-  const char *Needle = Str.data();
-  size_t N = Str.size();
-  if (N == 0)
-    return From;
-  if (Size < N)
-    return npos;
-  if (N == 1) {
-    const char *Ptr = (const char *)::memchr(Start, Needle[0], Size);
-    return Ptr == nullptr ? npos : Ptr - Data;
-  }
-
-  const char *Stop = Start + (Size - N + 1);
-
-  // For short haystacks or unsupported needles fall back to the naive algorithm
-  if (Size < 16 || N > 255) {
-    do {
-      if (std::memcmp(Start, Needle, N) == 0)
-        return Start - Data;
-      ++Start;
-    } while (Start < Stop);
-    return npos;
-  }
-
-  // Build the bad char heuristic table, with uint8_t to reduce cache thrashing.
-  uint8_t BadCharSkip[256];
-  std::memset(BadCharSkip, N, 256);
-  for (unsigned i = 0; i != N-1; ++i)
-    BadCharSkip[(uint8_t)Str[i]] = N-1-i;
-
-  do {
-    uint8_t Last = Start[N - 1];
-    if (LLVM_UNLIKELY(Last == (uint8_t)Needle[N - 1]))
-      if (std::memcmp(Start, Needle, N - 1) == 0)
-        return Start - Data;
-
-    // Otherwise skip the appropriate number of bytes.
-    Start += BadCharSkip[Last];
-  } while (Start < Stop);
-
-  return npos;
-}
-
-size_t StringRef::find_lower(StringRef Str, size_t From) const noexcept {
-  StringRef This = substr(From);
-  while (This.size() >= Str.size()) {
-    if (This.startswith_lower(Str))
-      return From;
-    This = This.drop_front();
-    ++From;
-  }
-  return npos;
-}
-
-size_t StringRef::rfind_lower(char C, size_t From) const noexcept {
-  From = std::min(From, Length);
-  size_t i = From;
-  while (i != 0) {
-    --i;
-    if (toLower(Data[i]) == toLower(C))
-      return i;
-  }
-  return npos;
-}
-
-/// rfind - Search for the last string \arg Str in the string.
-///
-/// \return - The index of the last occurrence of \arg Str, or npos if not
-/// found.
-size_t StringRef::rfind(StringRef Str) const noexcept {
-  size_t N = Str.size();
-  if (N > Length)
-    return npos;
-  for (size_t i = Length - N + 1, e = 0; i != e;) {
-    --i;
-    if (substr(i, N).equals(Str))
-      return i;
-  }
-  return npos;
-}
-
-size_t StringRef::rfind_lower(StringRef Str) const noexcept {
-  size_t N = Str.size();
-  if (N > Length)
-    return npos;
-  for (size_t i = Length - N + 1, e = 0; i != e;) {
-    --i;
-    if (substr(i, N).equals_lower(Str))
-      return i;
-  }
-  return npos;
-}
-
-/// find_first_of - Find the first character in the string that is in \arg
-/// Chars, or npos if not found.
-///
-/// Note: O(size() + Chars.size())
-StringRef::size_type StringRef::find_first_of(StringRef Chars,
-                                              size_t From) const noexcept {
-  std::bitset<1 << CHAR_BIT> CharBits;
-  for (size_type i = 0; i != Chars.size(); ++i)
-    CharBits.set((unsigned char)Chars[i]);
-
-  for (size_type i = std::min(From, Length), e = Length; i != e; ++i)
-    if (CharBits.test((unsigned char)Data[i]))
-      return i;
-  return npos;
-}
-
-/// find_first_not_of - Find the first character in the string that is not
-/// \arg C or npos if not found.
-StringRef::size_type StringRef::find_first_not_of(char C, size_t From) const noexcept {
-  for (size_type i = std::min(From, Length), e = Length; i != e; ++i)
-    if (Data[i] != C)
-      return i;
-  return npos;
-}
-
-/// find_first_not_of - Find the first character in the string that is not
-/// in the string \arg Chars, or npos if not found.
-///
-/// Note: O(size() + Chars.size())
-StringRef::size_type StringRef::find_first_not_of(StringRef Chars,
-                                                  size_t From) const noexcept {
-  std::bitset<1 << CHAR_BIT> CharBits;
-  for (size_type i = 0; i != Chars.size(); ++i)
-    CharBits.set((unsigned char)Chars[i]);
-
-  for (size_type i = std::min(From, Length), e = Length; i != e; ++i)
-    if (!CharBits.test((unsigned char)Data[i]))
-      return i;
-  return npos;
-}
-
-/// find_last_of - Find the last character in the string that is in \arg C,
-/// or npos if not found.
-///
-/// Note: O(size() + Chars.size())
-StringRef::size_type StringRef::find_last_of(StringRef Chars,
-                                             size_t From) const noexcept {
-  std::bitset<1 << CHAR_BIT> CharBits;
-  for (size_type i = 0; i != Chars.size(); ++i)
-    CharBits.set((unsigned char)Chars[i]);
-
-  for (size_type i = std::min(From, Length) - 1, e = -1; i != e; --i)
-    if (CharBits.test((unsigned char)Data[i]))
-      return i;
-  return npos;
-}
-
-/// find_last_not_of - Find the last character in the string that is not
-/// \arg C, or npos if not found.
-StringRef::size_type StringRef::find_last_not_of(char C, size_t From) const noexcept {
-  for (size_type i = std::min(From, Length) - 1, e = -1; i != e; --i)
-    if (Data[i] != C)
-      return i;
-  return npos;
-}
-
-/// find_last_not_of - Find the last character in the string that is not in
-/// \arg Chars, or npos if not found.
-///
-/// Note: O(size() + Chars.size())
-StringRef::size_type StringRef::find_last_not_of(StringRef Chars,
-                                                 size_t From) const noexcept {
-  std::bitset<1 << CHAR_BIT> CharBits;
-  for (size_type i = 0, e = Chars.size(); i != e; ++i)
-    CharBits.set((unsigned char)Chars[i]);
-
-  for (size_type i = std::min(From, Length) - 1, e = -1; i != e; --i)
-    if (!CharBits.test((unsigned char)Data[i]))
-      return i;
-  return npos;
-}
-
-void StringRef::split(SmallVectorImpl<StringRef> &A,
-                      StringRef Separator, int MaxSplit,
-                      bool KeepEmpty) const {
-  StringRef S = *this;
-
-  // Count down from MaxSplit. When MaxSplit is -1, this will just split
-  // "forever". This doesn't support splitting more than 2^31 times
-  // intentionally; if we ever want that we can make MaxSplit a 64-bit integer
-  // but that seems unlikely to be useful.
-  while (MaxSplit-- != 0) {
-    size_t Idx = S.find(Separator);
-    if (Idx == npos)
-      break;
-
-    // Push this split.
-    if (KeepEmpty || Idx > 0)
-      A.push_back(S.slice(0, Idx));
-
-    // Jump forward.
-    S = S.slice(Idx + Separator.size(), npos);
-  }
-
-  // Push the tail.
-  if (KeepEmpty || !S.empty())
-    A.push_back(S);
-}
-
-void StringRef::split(SmallVectorImpl<StringRef> &A, char Separator,
-                      int MaxSplit, bool KeepEmpty) const {
-  StringRef S = *this;
-
-  // Count down from MaxSplit. When MaxSplit is -1, this will just split
-  // "forever". This doesn't support splitting more than 2^31 times
-  // intentionally; if we ever want that we can make MaxSplit a 64-bit integer
-  // but that seems unlikely to be useful.
-  while (MaxSplit-- != 0) {
-    size_t Idx = S.find(Separator);
-    if (Idx == npos)
-      break;
-
-    // Push this split.
-    if (KeepEmpty || Idx > 0)
-      A.push_back(S.slice(0, Idx));
-
-    // Jump forward.
-    S = S.slice(Idx + 1, npos);
-  }
-
-  // Push the tail.
-  if (KeepEmpty || !S.empty())
-    A.push_back(S);
-}
-
-//===----------------------------------------------------------------------===//
-// Helpful Algorithms
-//===----------------------------------------------------------------------===//
-
-/// count - Return the number of non-overlapped occurrences of \arg Str in
-/// the string.
-size_t StringRef::count(StringRef Str) const noexcept {
-  size_t Count = 0;
-  size_t N = Str.size();
-  if (N > Length)
-    return 0;
-  for (size_t i = 0, e = Length - N + 1; i != e; ++i)
-    if (substr(i, N).equals(Str))
-      ++Count;
-  return Count;
-}
-
-static unsigned GetAutoSenseRadix(StringRef &Str) noexcept {
-  if (Str.empty())
-    return 10;
-
-  if (Str.startswith("0x") || Str.startswith("0X")) {
-    Str = Str.substr(2);
-    return 16;
-  }
-
-  if (Str.startswith("0b") || Str.startswith("0B")) {
-    Str = Str.substr(2);
-    return 2;
-  }
-
-  if (Str.startswith("0o")) {
-    Str = Str.substr(2);
-    return 8;
-  }
-
-  if (Str[0] == '0' && Str.size() > 1 && isDigit(Str[1])) {
-    Str = Str.substr(1);
-    return 8;
-  }
-
-  return 10;
-}
-
-bool wpi::consumeUnsignedInteger(StringRef &Str, unsigned Radix,
-                                  unsigned long long &Result) noexcept {
-  // Autosense radix if not specified.
-  if (Radix == 0)
-    Radix = GetAutoSenseRadix(Str);
-
-  // Empty strings (after the radix autosense) are invalid.
-  if (Str.empty()) return true;
-
-  // Parse all the bytes of the string given this radix.  Watch for overflow.
-  StringRef Str2 = Str;
-  Result = 0;
-  while (!Str2.empty()) {
-    unsigned CharVal;
-    if (Str2[0] >= '0' && Str2[0] <= '9')
-      CharVal = Str2[0] - '0';
-    else if (Str2[0] >= 'a' && Str2[0] <= 'z')
-      CharVal = Str2[0] - 'a' + 10;
-    else if (Str2[0] >= 'A' && Str2[0] <= 'Z')
-      CharVal = Str2[0] - 'A' + 10;
-    else
-      break;
-
-    // If the parsed value is larger than the integer radix, we cannot
-    // consume any more characters.
-    if (CharVal >= Radix)
-      break;
-
-    // Add in this character.
-    unsigned long long PrevResult = Result;
-    Result = Result * Radix + CharVal;
-
-    // Check for overflow by shifting back and seeing if bits were lost.
-    if (Result / Radix < PrevResult)
-      return true;
-
-    Str2 = Str2.substr(1);
-  }
-
-  // We consider the operation a failure if no characters were consumed
-  // successfully.
-  if (Str.size() == Str2.size())
-    return true;
-
-  Str = Str2;
-  return false;
-}
-
-bool wpi::consumeSignedInteger(StringRef &Str, unsigned Radix,
-                                long long &Result) noexcept {
-  unsigned long long ULLVal;
-
-  // Handle positive strings first.
-  if (Str.empty() || Str.front() != '-') {
-    if (consumeUnsignedInteger(Str, Radix, ULLVal) ||
-        // Check for value so large it overflows a signed value.
-        (long long)ULLVal < 0)
-      return true;
-    Result = ULLVal;
-    return false;
-  }
-
-  // Get the positive part of the value.
-  StringRef Str2 = Str.drop_front(1);
-  if (consumeUnsignedInteger(Str2, Radix, ULLVal) ||
-      // Reject values so large they'd overflow as negative signed, but allow
-      // "-0".  This negates the unsigned so that the negative isn't undefined
-      // on signed overflow.
-      (long long)-ULLVal > 0)
-    return true;
-
-  Str = Str2;
-  Result = -ULLVal;
-  return false;
-}
-
-/// GetAsUnsignedInteger - Workhorse method that converts a integer character
-/// sequence of radix up to 36 to an unsigned long long value.
-bool wpi::getAsUnsignedInteger(StringRef Str, unsigned Radix,
-                                unsigned long long &Result) noexcept {
-  if (consumeUnsignedInteger(Str, Radix, Result))
-    return true;
-
-  // For getAsUnsignedInteger, we require the whole string to be consumed or
-  // else we consider it a failure.
-  return !Str.empty();
-}
-
-bool wpi::getAsSignedInteger(StringRef Str, unsigned Radix,
-                              long long &Result) noexcept {
-  if (consumeSignedInteger(Str, Radix, Result))
-    return true;
-
-  // For getAsSignedInteger, we require the whole string to be consumed or else
-  // we consider it a failure.
-  return !Str.empty();
-}
-
-std::ostream &wpi::operator<<(std::ostream &os, StringRef string) {
-  os.write(string.data(), string.size());
-  return os;
-}
-
-// Implementation of StringRef hashing.
-hash_code wpi::hash_value(StringRef S) {
-  return hash_combine_range(S.begin(), S.end());
-}
diff --git a/wpiutil/src/main/native/cpp/llvm/Twine.cpp b/wpiutil/src/main/native/cpp/llvm/Twine.cpp
deleted file mode 100644
index b8dd7c308e..0000000000
--- a/wpiutil/src/main/native/cpp/llvm/Twine.cpp
+++ /dev/null
@@ -1,176 +0,0 @@
-//===-- Twine.cpp - Fast Temporary String Concatenation -------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#include "wpi/Twine.h"
-#include "wpi/SmallString.h"
-#include "wpi/raw_ostream.h"
-using namespace wpi;
-
-std::string Twine::str() const {
-  // If we're storing only a std::string, just return it.
-  if (LHSKind == StdStringKind && RHSKind == EmptyKind)
-    return *LHS.stdString;
-
-  // Otherwise, flatten and copy the contents first.
-  SmallString<256> Vec;
-  return toStringRef(Vec).str();
-}
-
-void Twine::toVector(SmallVectorImpl<char> &Out) const {
-  raw_svector_ostream OS(Out);
-  print(OS);
-}
-
-StringRef Twine::toNullTerminatedStringRef(SmallVectorImpl<char> &Out) const {
-  if (isUnary()) {
-    switch (getLHSKind()) {
-    case CStringKind:
-      // Already null terminated, yay!
-      return StringRef(LHS.cString);
-    case StdStringKind: {
-      const std::string *str = LHS.stdString;
-      return StringRef(str->c_str(), str->size());
-    }
-    default:
-      break;
-    }
-  }
-  toVector(Out);
-  Out.push_back(0);
-  Out.pop_back();
-  return StringRef(Out.data(), Out.size());
-}
-
-void Twine::printOneChild(raw_ostream &OS, Child Ptr,
-                          NodeKind Kind) const {
-  switch (Kind) {
-  case Twine::NullKind: break;
-  case Twine::EmptyKind: break;
-  case Twine::TwineKind:
-    Ptr.twine->print(OS);
-    break;
-  case Twine::CStringKind:
-    OS << Ptr.cString;
-    break;
-  case Twine::StdStringKind:
-    OS << *Ptr.stdString;
-    break;
-  case Twine::StringRefKind:
-    OS << *Ptr.stringRef;
-    break;
-  case Twine::StringViewKind:
-    OS << *Ptr.stringView;
-    break;
-  case Twine::SmallStringKind:
-    OS << *Ptr.smallString;
-    break;
-  case Twine::CharKind:
-    OS << Ptr.character;
-    break;
-  case Twine::DecUIKind:
-    OS << Ptr.decUI;
-    break;
-  case Twine::DecIKind:
-    OS << Ptr.decI;
-    break;
-  case Twine::DecULKind:
-    OS << *Ptr.decUL;
-    break;
-  case Twine::DecLKind:
-    OS << *Ptr.decL;
-    break;
-  case Twine::DecULLKind:
-    OS << *Ptr.decULL;
-    break;
-  case Twine::DecLLKind:
-    OS << *Ptr.decLL;
-    break;
-  case Twine::UHexKind:
-    OS.write_hex(*Ptr.uHex);
-    break;
-  }
-}
-
-void Twine::printOneChildRepr(raw_ostream &OS, Child Ptr,
-                              NodeKind Kind) const {
-  switch (Kind) {
-  case Twine::NullKind:
-    OS << "null"; break;
-  case Twine::EmptyKind:
-    OS << "empty"; break;
-  case Twine::TwineKind:
-    OS << "rope:";
-    Ptr.twine->printRepr(OS);
-    break;
-  case Twine::CStringKind:
-    OS << "cstring:\""
-       << Ptr.cString << "\"";
-    break;
-  case Twine::StdStringKind:
-    OS << "std::string:\""
-       << Ptr.stdString << "\"";
-    break;
-  case Twine::StringRefKind:
-    OS << "stringref:\""
-       << Ptr.stringRef << "\"";
-    break;
-  case Twine::StringViewKind:
-    OS << "std::string_view:\""
-       << Ptr.stringView << "\"";
-    break;
-  case Twine::SmallStringKind:
-    OS << "smallstring:\"" << *Ptr.smallString << "\"";
-    break;
-  case Twine::CharKind:
-    OS << "char:\"" << Ptr.character << "\"";
-    break;
-  case Twine::DecUIKind:
-    OS << "decUI:\"" << Ptr.decUI << "\"";
-    break;
-  case Twine::DecIKind:
-    OS << "decI:\"" << Ptr.decI << "\"";
-    break;
-  case Twine::DecULKind:
-    OS << "decUL:\"" << *Ptr.decUL << "\"";
-    break;
-  case Twine::DecLKind:
-    OS << "decL:\"" << *Ptr.decL << "\"";
-    break;
-  case Twine::DecULLKind:
-    OS << "decULL:\"" << *Ptr.decULL << "\"";
-    break;
-  case Twine::DecLLKind:
-    OS << "decLL:\"" << *Ptr.decLL << "\"";
-    break;
-  case Twine::UHexKind:
-    OS << "uhex:\"" << Ptr.uHex << "\"";
-    break;
-  }
-}
-
-void Twine::print(raw_ostream &OS) const {
-  printOneChild(OS, LHS, getLHSKind());
-  printOneChild(OS, RHS, getRHSKind());
-}
-
-void Twine::printRepr(raw_ostream &OS) const {
-  OS << "(Twine ";
-  printOneChildRepr(OS, LHS, getLHSKind());
-  OS << " ";
-  printOneChildRepr(OS, RHS, getRHSKind());
-  OS << ")";
-}
-
-LLVM_DUMP_METHOD void Twine::dump() const {
-  print(errs());
-}
-
-LLVM_DUMP_METHOD void Twine::dumpRepr() const {
-  printRepr(errs());
-}
diff --git a/wpiutil/src/main/native/cpp/llvm/Windows/WindowsSupport.h b/wpiutil/src/main/native/cpp/llvm/Windows/WindowsSupport.h
index d830e330ec..7307337977 100644
--- a/wpiutil/src/main/native/cpp/llvm/Windows/WindowsSupport.h
+++ b/wpiutil/src/main/native/cpp/llvm/Windows/WindowsSupport.h
@@ -36,13 +36,12 @@
 
 #include "wpi/SmallVector.h"
 #include "wpi/StringExtras.h"
-#include "wpi/StringRef.h"
-#include "wpi/Twine.h"
 #include "wpi/Chrono.h"
 #include "wpi/Compiler.h"
 #include "wpi/VersionTuple.h"
 #include <cassert>
 #include <string>
+#include <string_view>
 #include <system_error>
 #define WIN32_NO_STATUS
 #include <windows.h>
diff --git a/wpiutil/src/main/native/cpp/llvm/raw_ostream.cpp b/wpiutil/src/main/native/cpp/llvm/raw_ostream.cpp
index 9c7e72dd64..b33df58266 100644
--- a/wpiutil/src/main/native/cpp/llvm/raw_ostream.cpp
+++ b/wpiutil/src/main/native/cpp/llvm/raw_ostream.cpp
@@ -22,9 +22,7 @@
 #include "wpi/StringExtras.h"
 #include "wpi/Compiler.h"
 #include "wpi/ErrorHandling.h"
-#include "wpi/Format.h"
 #include "wpi/MathExtras.h"
-#include "wpi/NativeFormatting.h"
 #include "wpi/WindowsError.h"
 #include "wpi/fs.h"
 #include <algorithm>
@@ -113,32 +111,7 @@ void raw_ostream::SetBufferAndMode(char *BufferStart, size_t Size,
   assert(OutBufStart <= OutBufEnd && "Invalid size!");
 }
 
-raw_ostream &raw_ostream::operator<<(unsigned long N) {
-  write_integer(*this, static_cast<uint64_t>(N), 0, IntegerStyle::Integer);
-  return *this;
-}
-
-raw_ostream &raw_ostream::operator<<(long N) {
-  write_integer(*this, static_cast<int64_t>(N), 0, IntegerStyle::Integer);
-  return *this;
-}
-
-raw_ostream &raw_ostream::operator<<(unsigned long long N) {
-  write_integer(*this, static_cast<uint64_t>(N), 0, IntegerStyle::Integer);
-  return *this;
-}
-
-raw_ostream &raw_ostream::operator<<(long long N) {
-  write_integer(*this, static_cast<int64_t>(N), 0, IntegerStyle::Integer);
-  return *this;
-}
-
-raw_ostream &raw_ostream::write_hex(unsigned long long N) {
-  wpi::write_hex(*this, N, HexPrintStyle::Lower);
-  return *this;
-}
-
-raw_ostream &raw_ostream::write_escaped(StringRef Str,
+raw_ostream &raw_ostream::write_escaped(std::string_view Str,
                                         bool UseHexEscapes) {
   for (unsigned char c : Str) {
     switch (c) {
@@ -178,16 +151,6 @@ raw_ostream &raw_ostream::write_escaped(StringRef Str,
   return *this;
 }
 
-raw_ostream &raw_ostream::operator<<(const void *P) {
-  wpi::write_hex(*this, (uintptr_t)P, HexPrintStyle::PrefixLower);
-  return *this;
-}
-
-raw_ostream &raw_ostream::operator<<(double N) {
-  wpi::write_double(*this, N, FloatStyle::Exponent);
-  return *this;
-}
-
 void raw_ostream::flush_nonempty() {
   assert(OutBufCur > OutBufStart && "Invalid call to flush_nonempty.");
   size_t Length = OutBufCur - OutBufStart;
@@ -277,170 +240,6 @@ void raw_ostream::copy_to_buffer(const char *Ptr, size_t Size) {
   OutBufCur += Size;
 }
 
-// Formatted output.
-raw_ostream &raw_ostream::operator<<(const format_object_base &Fmt) {
-  // If we have more than a few bytes left in our output buffer, try
-  // formatting directly onto its end.
-  size_t NextBufferSize = 127;
-  size_t BufferBytesLeft = OutBufEnd - OutBufCur;
-  if (BufferBytesLeft > 3) {
-    size_t BytesUsed = Fmt.print(OutBufCur, BufferBytesLeft);
-
-    // Common case is that we have plenty of space.
-    if (BytesUsed <= BufferBytesLeft) {
-      OutBufCur += BytesUsed;
-      return *this;
-    }
-
-    // Otherwise, we overflowed and the return value tells us the size to try
-    // again with.
-    NextBufferSize = BytesUsed;
-  }
-
-  // If we got here, we didn't have enough space in the output buffer for the
-  // string.  Try printing into a SmallVector that is resized to have enough
-  // space.  Iterate until we win.
-  SmallVector<char, 128> V;
-
-  while (true) {
-    V.resize(NextBufferSize);
-
-    // Try formatting into the SmallVector.
-    size_t BytesUsed = Fmt.print(V.data(), NextBufferSize);
-
-    // If BytesUsed fit into the vector, we win.
-    if (BytesUsed <= NextBufferSize)
-      return write(V.data(), BytesUsed);
-
-    // Otherwise, try again with a new size.
-    assert(BytesUsed > NextBufferSize && "Didn't grow buffer!?");
-    NextBufferSize = BytesUsed;
-  }
-}
-
-raw_ostream &raw_ostream::operator<<(const FormattedString &FS) {
-  if (FS.Str.size() >= FS.Width || FS.Justify == FormattedString::JustifyNone) {
-    this->operator<<(FS.Str);
-    return *this;
-  }
-  const size_t Difference = FS.Width - FS.Str.size();
-  switch (FS.Justify) {
-  case FormattedString::JustifyLeft:
-    this->operator<<(FS.Str);
-    this->indent(Difference);
-    break;
-  case FormattedString::JustifyRight:
-    this->indent(Difference);
-    this->operator<<(FS.Str);
-    break;
-  case FormattedString::JustifyCenter: {
-    int PadAmount = Difference / 2;
-    this->indent(PadAmount);
-    this->operator<<(FS.Str);
-    this->indent(Difference - PadAmount);
-    break;
-  }
-  default:
-    wpi_unreachable("Bad Justification");
-  }
-  return *this;
-}
-
-raw_ostream &raw_ostream::operator<<(const FormattedNumber &FN) {
-  if (FN.Hex) {
-    HexPrintStyle Style;
-    if (FN.Upper && FN.HexPrefix)
-      Style = HexPrintStyle::PrefixUpper;
-    else if (FN.Upper && !FN.HexPrefix)
-      Style = HexPrintStyle::Upper;
-    else if (!FN.Upper && FN.HexPrefix)
-      Style = HexPrintStyle::PrefixLower;
-    else
-      Style = HexPrintStyle::Lower;
-    wpi::write_hex(*this, FN.HexValue, Style, FN.Width);
-  } else {
-    wpi::SmallString<16> Buffer;
-    wpi::raw_svector_ostream Stream(Buffer);
-    wpi::write_integer(Stream, FN.DecValue, 0, IntegerStyle::Integer);
-    if (Buffer.size() < FN.Width)
-      indent(FN.Width - Buffer.size());
-    (*this) << Buffer;
-  }
-  return *this;
-}
-
-raw_ostream &raw_ostream::operator<<(const FormattedBytes &FB) {
-  if (FB.Bytes.empty())
-    return *this;
-
-  size_t LineIndex = 0;
-  auto Bytes = FB.Bytes;
-  const size_t Size = Bytes.size();
-  HexPrintStyle HPS = FB.Upper ? HexPrintStyle::Upper : HexPrintStyle::Lower;
-  uint64_t OffsetWidth = 0;
-  if (FB.FirstByteOffset.has_value()) {
-    // Figure out how many nibbles are needed to print the largest offset
-    // represented by this data set, so that we can align the offset field
-    // to the right width.
-    size_t Lines = Size / FB.NumPerLine;
-    uint64_t MaxOffset = *FB.FirstByteOffset + Lines * FB.NumPerLine;
-    unsigned Power = 0;
-    if (MaxOffset > 0)
-      Power = wpi::Log2_64_Ceil(MaxOffset);
-    OffsetWidth = std::max<uint64_t>(4, wpi::alignTo(Power, 4) / 4);
-  }
-
-  // The width of a block of data including all spaces for group separators.
-  unsigned NumByteGroups =
-      alignTo(FB.NumPerLine, FB.ByteGroupSize) / FB.ByteGroupSize;
-  unsigned BlockCharWidth = FB.NumPerLine * 2 + NumByteGroups - 1;
-
-  while (!Bytes.empty()) {
-    indent(FB.IndentLevel);
-
-    if (FB.FirstByteOffset.has_value()) {
-      uint64_t Offset = FB.FirstByteOffset.value();
-      wpi::write_hex(*this, Offset + LineIndex, HPS, OffsetWidth);
-      *this << ": ";
-    }
-
-    auto Line = Bytes.take_front(FB.NumPerLine);
-
-    size_t CharsPrinted = 0;
-    // Print the hex bytes for this line in groups
-    for (size_t I = 0; I < Line.size(); ++I, CharsPrinted += 2) {
-      if (I && (I % FB.ByteGroupSize) == 0) {
-        ++CharsPrinted;
-        *this << " ";
-      }
-      wpi::write_hex(*this, Line[I], HPS, 2);
-    }
-
-    if (FB.ASCII) {
-      // Print any spaces needed for any bytes that we didn't print on this
-      // line so that the ASCII bytes are correctly aligned.
-      assert(BlockCharWidth >= CharsPrinted);
-      indent(BlockCharWidth - CharsPrinted + 2);
-      *this << "|";
-
-      // Print the ASCII char values for each byte on this line
-      for (uint8_t Byte : Line) {
-        if (isPrint(Byte))
-          *this << static_cast<char>(Byte);
-        else
-          *this << '.';
-      }
-      *this << '|';
-    }
-
-    Bytes = Bytes.drop_front(Line.size());
-    LineIndex += Line.size();
-    if (LineIndex < Size)
-      *this << '\n';
-  }
-  return *this;
-}
-
 template <char C>
 static raw_ostream &write_padding(raw_ostream &OS, unsigned NumChars) {
   static const char Chars[] = {C, C, C, C, C, C, C, C, C, C, C, C, C, C, C, C,
@@ -474,19 +273,11 @@ raw_ostream &raw_ostream::write_zeros(unsigned NumZeros) {
 
 void raw_ostream::anchor() {}
 
-//===----------------------------------------------------------------------===//
-//  Formatted Output
-//===----------------------------------------------------------------------===//
-
-// Out of line virtual method.
-void format_object_base::home() {
-}
-
 //===----------------------------------------------------------------------===//
 //  raw_fd_ostream
 //===----------------------------------------------------------------------===//
 
-static int getFD(StringRef Filename, std::error_code &EC,
+static int getFD(std::string_view Filename, std::error_code &EC,
                  fs::CreationDisposition Disp, fs::FileAccess Access,
                  fs::OpenFlags Flags) {
   assert((Access & fs::FA_Write) &&
@@ -521,25 +312,25 @@ static int getFD(StringRef Filename, std::error_code &EC,
   return FD;
 }
 
-raw_fd_ostream::raw_fd_ostream(StringRef Filename, std::error_code &EC)
+raw_fd_ostream::raw_fd_ostream(std::string_view Filename, std::error_code &EC)
     : raw_fd_ostream(Filename, EC, fs::CD_CreateAlways, fs::FA_Write,
                      fs::OF_None) {}
 
-raw_fd_ostream::raw_fd_ostream(StringRef Filename, std::error_code &EC,
+raw_fd_ostream::raw_fd_ostream(std::string_view Filename, std::error_code &EC,
                                fs::CreationDisposition Disp)
     : raw_fd_ostream(Filename, EC, Disp, fs::FA_Write, fs::OF_None) {}
 
-raw_fd_ostream::raw_fd_ostream(StringRef Filename, std::error_code &EC,
+raw_fd_ostream::raw_fd_ostream(std::string_view Filename, std::error_code &EC,
                                fs::FileAccess Access)
     : raw_fd_ostream(Filename, EC, fs::CD_CreateAlways, Access,
                      fs::OF_None) {}
 
-raw_fd_ostream::raw_fd_ostream(StringRef Filename, std::error_code &EC,
+raw_fd_ostream::raw_fd_ostream(std::string_view Filename, std::error_code &EC,
                                fs::OpenFlags Flags)
     : raw_fd_ostream(Filename, EC, fs::CD_CreateAlways, fs::FA_Write,
                      Flags) {}
 
-raw_fd_ostream::raw_fd_ostream(StringRef Filename, std::error_code &EC,
+raw_fd_ostream::raw_fd_ostream(std::string_view Filename, std::error_code &EC,
                                fs::CreationDisposition Disp,
                                fs::FileAccess Access,
                                fs::OpenFlags Flags)
@@ -622,7 +413,7 @@ raw_fd_ostream::~raw_fd_ostream() {
 // the input is UTF-8 or transcode from the local codepage to UTF-8 before
 // quoting it. If they don't, this may mess up the encoding, but this is still
 // probably the best compromise we can make.
-static bool write_console_impl(int FD, StringRef Data) {
+static bool write_console_impl(int FD, std::string_view Data) {
   SmallVector<wchar_t, 256> WideText;
 
   // Fall back to ::write if it wasn't valid UTF-8.
@@ -665,7 +456,7 @@ void raw_fd_ostream::write_impl(const char *Ptr, size_t Size) {
   // If this is a Windows console device, try re-encoding from UTF-8 to UTF-16
   // and using WriteConsoleW. If that fails, fall back to plain write().
   if (IsWindowsConsole)
-    if (write_console_impl(FD, StringRef(Ptr, Size)))
+    if (write_console_impl(FD, std::string_view(Ptr, Size)))
       return;
 #endif
 
diff --git a/wpiutil/src/main/native/cpp/raw_istream.cpp b/wpiutil/src/main/native/cpp/raw_istream.cpp
index 4cf4dfab28..a179b982ba 100644
--- a/wpiutil/src/main/native/cpp/raw_istream.cpp
+++ b/wpiutil/src/main/native/cpp/raw_istream.cpp
@@ -14,9 +14,9 @@
 
 #include <cstdlib>
 #include <cstring>
+#include <string_view>
 
 #include "wpi/SmallVector.h"
-#include "wpi/StringRef.h"
 #include "wpi/fs.h"
 
 #if defined(_MSC_VER)
@@ -33,13 +33,13 @@
 
 using namespace wpi;
 
-StringRef raw_istream::getline(SmallVectorImpl<char>& buf, int maxLen) {
+std::string_view raw_istream::getline(SmallVectorImpl<char>& buf, int maxLen) {
   buf.clear();
   for (int i = 0; i < maxLen; ++i) {
     char c;
     read(c);
     if (has_error()) {
-      return StringRef{buf.data(), buf.size()};
+      return {buf.data(), buf.size()};
     }
     if (c == '\r') {
       continue;
@@ -49,7 +49,7 @@ StringRef raw_istream::getline(SmallVectorImpl<char>& buf, int maxLen) {
       break;
     }
   }
-  return StringRef{buf.data(), buf.size()};
+  return {buf.data(), buf.size()};
 }
 
 void raw_mem_istream::close() {}
@@ -69,16 +69,16 @@ void raw_mem_istream::read_impl(void* data, size_t len) {
   set_read_count(len);
 }
 
-static int getFD(const Twine& Filename, std::error_code& EC) {
+static int getFD(std::string_view Filename, std::error_code& EC) {
   // Handle "-" as stdin. Note that when we do this, we consider ourself
   // the owner of stdin. This means that we can do things like close the
   // file descriptor when we're done and set the "binary" flag globally.
-  if (Filename.isSingleStringRef() && Filename.getSingleStringRef() == "-") {
+  if (Filename == "-") {
     EC = std::error_code();
     return STDIN_FILENO;
   }
 
-  fs::file_t F = fs::OpenFileForRead(Filename.str(), EC);
+  fs::file_t F = fs::OpenFileForRead(Filename, EC);
   if (EC) {
     return -1;
   }
@@ -89,7 +89,7 @@ static int getFD(const Twine& Filename, std::error_code& EC) {
   return FD;
 }
 
-raw_fd_istream::raw_fd_istream(const Twine& filename, std::error_code& ec,
+raw_fd_istream::raw_fd_istream(std::string_view filename, std::error_code& ec,
                                size_t bufSize)
     : raw_fd_istream(getFD(filename, ec), true, bufSize) {}
 
diff --git a/wpiutil/src/main/native/cpp/sha1.cpp b/wpiutil/src/main/native/cpp/sha1.cpp
index 3ad297a4dc..5319afb1db 100644
--- a/wpiutil/src/main/native/cpp/sha1.cpp
+++ b/wpiutil/src/main/native/cpp/sha1.cpp
@@ -216,7 +216,7 @@ SHA1::SHA1() {
   reset(digest, buf_size, transforms);
 }
 
-void SHA1::Update(StringRef s) {
+void SHA1::Update(std::string_view s) {
   raw_mem_istream is(makeArrayRef(s.data(), s.size()));
   Update(is);
 }
@@ -293,7 +293,7 @@ std::string SHA1::Final() {
   return os.str();
 }
 
-StringRef SHA1::Final(SmallVectorImpl<char>& buf) {
+std::string_view SHA1::Final(SmallVectorImpl<char>& buf) {
   raw_svector_ostream os(buf);
 
   finalize(digest, buffer, buf_size, transforms, os, true);
@@ -301,7 +301,7 @@ StringRef SHA1::Final(SmallVectorImpl<char>& buf) {
   return os.str();
 }
 
-StringRef SHA1::RawFinal(SmallVectorImpl<char>& buf) {
+std::string_view SHA1::RawFinal(SmallVectorImpl<char>& buf) {
   raw_svector_ostream os(buf);
 
   finalize(digest, buffer, buf_size, transforms, os, false);
@@ -309,7 +309,7 @@ StringRef SHA1::RawFinal(SmallVectorImpl<char>& buf) {
   return os.str();
 }
 
-std::string SHA1::FromFile(StringRef filename) {
+std::string SHA1::FromFile(std::string_view filename) {
   std::error_code ec;
   raw_fd_istream stream(filename, ec);
   SHA1 checksum;
diff --git a/wpiutil/src/main/native/cpp/uv/FsEvent.cpp b/wpiutil/src/main/native/cpp/uv/FsEvent.cpp
index 0b9dfe85ef..3c83d1d00a 100644
--- a/wpiutil/src/main/native/cpp/uv/FsEvent.cpp
+++ b/wpiutil/src/main/native/cpp/uv/FsEvent.cpp
@@ -22,8 +22,8 @@ std::shared_ptr<FsEvent> FsEvent::Create(Loop& loop) {
   return h;
 }
 
-void FsEvent::Start(const Twine& path, unsigned int flags) {
-  SmallString<128> pathBuf;
+void FsEvent::Start(std::string_view path, unsigned int flags) {
+  SmallString<128> pathBuf{path};
   Invoke(
       &uv_fs_event_start, GetRaw(),
       [](uv_fs_event_t* handle, const char* filename, int events, int status) {
@@ -34,7 +34,7 @@ void FsEvent::Start(const Twine& path, unsigned int flags) {
           h.fsEvent(filename, events);
         }
       },
-      path.toNullTerminatedStringRef(pathBuf).data(), flags);
+      pathBuf.c_str(), flags);
 }
 
 std::string FsEvent::GetPath() {
diff --git a/wpiutil/src/main/native/cpp/uv/GetAddrInfo.cpp b/wpiutil/src/main/native/cpp/uv/GetAddrInfo.cpp
index cb0a679e61..e4f7aa4f53 100644
--- a/wpiutil/src/main/native/cpp/uv/GetAddrInfo.cpp
+++ b/wpiutil/src/main/native/cpp/uv/GetAddrInfo.cpp
@@ -4,6 +4,7 @@
 
 #include "wpi/uv/GetAddrInfo.h"
 
+#include "wpi/SmallString.h"
 #include "wpi/uv/Loop.h"
 #include "wpi/uv/util.h"
 
@@ -14,10 +15,10 @@ GetAddrInfoReq::GetAddrInfoReq() {
 }
 
 void GetAddrInfo(Loop& loop, const std::shared_ptr<GetAddrInfoReq>& req,
-                 const Twine& node, const Twine& service,
+                 std::string_view node, std::string_view service,
                  const addrinfo* hints) {
-  SmallVector<char, 128> nodeStr;
-  SmallVector<char, 128> serviceStr;
+  SmallString<128> nodeStr{node};
+  SmallString<128> serviceStr{service};
   int err = uv_getaddrinfo(
       loop.GetRaw(), req->GetRaw(),
       [](uv_getaddrinfo_t* req, int status, addrinfo* res) {
@@ -30,10 +31,8 @@ void GetAddrInfo(Loop& loop, const std::shared_ptr<GetAddrInfoReq>& req,
         uv_freeaddrinfo(res);
         h.Release();  // this is always a one-shot
       },
-      node.isNull() ? nullptr : node.toNullTerminatedStringRef(nodeStr).data(),
-      service.isNull() ? nullptr
-                       : service.toNullTerminatedStringRef(serviceStr).data(),
-      hints);
+      node.empty() ? nullptr : nodeStr.c_str(),
+      service.empty() ? nullptr : serviceStr.c_str(), hints);
   if (err < 0) {
     loop.ReportError(err);
   } else {
@@ -42,7 +41,7 @@ void GetAddrInfo(Loop& loop, const std::shared_ptr<GetAddrInfoReq>& req,
 }
 
 void GetAddrInfo(Loop& loop, std::function<void(const addrinfo&)> callback,
-                 const Twine& node, const Twine& service,
+                 std::string_view node, std::string_view service,
                  const addrinfo* hints) {
   auto req = std::make_shared<GetAddrInfoReq>();
   req->resolved.connect(callback);
diff --git a/wpiutil/src/main/native/cpp/uv/GetNameInfo.cpp b/wpiutil/src/main/native/cpp/uv/GetNameInfo.cpp
index 701fc77fb7..7bc412d6ff 100644
--- a/wpiutil/src/main/native/cpp/uv/GetNameInfo.cpp
+++ b/wpiutil/src/main/native/cpp/uv/GetNameInfo.cpp
@@ -44,7 +44,7 @@ void GetNameInfo(Loop& loop,
 }
 
 void GetNameInfo4(Loop& loop, const std::shared_ptr<GetNameInfoReq>& req,
-                  const Twine& ip, unsigned int port, int flags) {
+                  std::string_view ip, unsigned int port, int flags) {
   sockaddr_in addr;
   int err = NameToAddr(ip, port, &addr);
   if (err < 0) {
@@ -56,7 +56,7 @@ void GetNameInfo4(Loop& loop, const std::shared_ptr<GetNameInfoReq>& req,
 
 void GetNameInfo4(Loop& loop,
                   std::function<void(const char*, const char*)> callback,
-                  const Twine& ip, unsigned int port, int flags) {
+                  std::string_view ip, unsigned int port, int flags) {
   sockaddr_in addr;
   int err = NameToAddr(ip, port, &addr);
   if (err < 0) {
@@ -67,7 +67,7 @@ void GetNameInfo4(Loop& loop,
 }
 
 void GetNameInfo6(Loop& loop, const std::shared_ptr<GetNameInfoReq>& req,
-                  const Twine& ip, unsigned int port, int flags) {
+                  std::string_view ip, unsigned int port, int flags) {
   sockaddr_in6 addr;
   int err = NameToAddr(ip, port, &addr);
   if (err < 0) {
@@ -79,7 +79,7 @@ void GetNameInfo6(Loop& loop, const std::shared_ptr<GetNameInfoReq>& req,
 
 void GetNameInfo6(Loop& loop,
                   std::function<void(const char*, const char*)> callback,
-                  const Twine& ip, unsigned int port, int flags) {
+                  std::string_view ip, unsigned int port, int flags) {
   sockaddr_in6 addr;
   int err = NameToAddr(ip, port, &addr);
   if (err < 0) {
diff --git a/wpiutil/src/main/native/cpp/uv/NameToAddr.cpp b/wpiutil/src/main/native/cpp/uv/NameToAddr.cpp
index 55ec9c14fe..23ec6da6fa 100644
--- a/wpiutil/src/main/native/cpp/uv/NameToAddr.cpp
+++ b/wpiutil/src/main/native/cpp/uv/NameToAddr.cpp
@@ -10,53 +10,49 @@
 
 namespace wpi::uv {
 
-int NameToAddr(const Twine& ip, unsigned int port, sockaddr_in* addr) {
-  SmallString<128> tmp;
-  StringRef ipStr = ip.toNullTerminatedStringRef(tmp);
-  if (ipStr.empty()) {
+int NameToAddr(std::string_view ip, unsigned int port, sockaddr_in* addr) {
+  if (ip.empty()) {
     std::memset(addr, 0, sizeof(sockaddr_in));
     addr->sin_family = PF_INET;
     addr->sin_addr.s_addr = INADDR_ANY;
     addr->sin_port = htons(port);
     return 0;
   } else {
-    return uv_ip4_addr(ipStr.data(), port, addr);
+    SmallString<128> ipBuf{ip};
+    return uv_ip4_addr(ipBuf.c_str(), port, addr);
   }
 }
 
-int NameToAddr(const Twine& ip, unsigned int port, sockaddr_in6* addr) {
-  SmallString<128> tmp;
-  StringRef ipStr = ip.toNullTerminatedStringRef(tmp);
-  if (ipStr.empty()) {
+int NameToAddr(std::string_view ip, unsigned int port, sockaddr_in6* addr) {
+  if (ip.empty()) {
     std::memset(addr, 0, sizeof(sockaddr_in6));
     addr->sin6_family = PF_INET6;
     addr->sin6_addr = in6addr_any;
     addr->sin6_port = htons(port);
     return 0;
   } else {
-    return uv_ip6_addr(ipStr.data(), port, addr);
+    SmallString<128> ipBuf{ip};
+    return uv_ip6_addr(ipBuf.c_str(), port, addr);
   }
 }
 
-int NameToAddr(const Twine& ip, in_addr* addr) {
-  SmallString<128> tmp;
-  StringRef ipStr = ip.toNullTerminatedStringRef(tmp);
-  if (ipStr.empty()) {
+int NameToAddr(std::string_view ip, in_addr* addr) {
+  if (ip.empty()) {
     addr->s_addr = INADDR_ANY;
     return 0;
   } else {
-    return uv_inet_pton(AF_INET, ipStr.data(), addr);
+    SmallString<128> ipBuf{ip};
+    return uv_inet_pton(AF_INET, ipBuf.c_str(), addr);
   }
 }
 
-int NameToAddr(const Twine& ip, in6_addr* addr) {
-  SmallString<128> tmp;
-  StringRef ipStr = ip.toNullTerminatedStringRef(tmp);
-  if (ipStr.empty()) {
+int NameToAddr(std::string_view ip, in6_addr* addr) {
+  if (ip.empty()) {
     *addr = in6addr_any;
     return 0;
   } else {
-    return uv_inet_pton(AF_INET6, ipStr.data(), addr);
+    SmallString<128> ipBuf{ip};
+    return uv_inet_pton(AF_INET6, ipBuf.c_str(), addr);
   }
 }
 
diff --git a/wpiutil/src/main/native/cpp/uv/Pipe.cpp b/wpiutil/src/main/native/cpp/uv/Pipe.cpp
index 4834d69988..ae4f6ef842 100644
--- a/wpiutil/src/main/native/cpp/uv/Pipe.cpp
+++ b/wpiutil/src/main/native/cpp/uv/Pipe.cpp
@@ -62,17 +62,15 @@ Pipe* Pipe::DoAccept() {
   return Accept().get();
 }
 
-void Pipe::Bind(const Twine& name) {
-  SmallString<128> nameBuf;
-  Invoke(&uv_pipe_bind, GetRaw(),
-         name.toNullTerminatedStringRef(nameBuf).data());
+void Pipe::Bind(std::string_view name) {
+  SmallString<128> nameBuf{name};
+  Invoke(&uv_pipe_bind, GetRaw(), nameBuf.c_str());
 }
 
-void Pipe::Connect(const Twine& name,
+void Pipe::Connect(std::string_view name,
                    const std::shared_ptr<PipeConnectReq>& req) {
-  SmallString<128> nameBuf;
-  uv_pipe_connect(req->GetRaw(), GetRaw(),
-                  name.toNullTerminatedStringRef(nameBuf).data(),
+  SmallString<128> nameBuf{name};
+  uv_pipe_connect(req->GetRaw(), GetRaw(), nameBuf.c_str(),
                   [](uv_connect_t* req, int status) {
                     auto& h = *static_cast<PipeConnectReq*>(req->data);
                     if (status < 0) {
@@ -85,7 +83,7 @@ void Pipe::Connect(const Twine& name,
   req->Keep();
 }
 
-void Pipe::Connect(const Twine& name, std::function<void()> callback) {
+void Pipe::Connect(std::string_view name, std::function<void()> callback) {
   auto req = std::make_shared<PipeConnectReq>();
   req->connected.connect(callback);
   Connect(name, req);
diff --git a/wpiutil/src/main/native/cpp/uv/Process.cpp b/wpiutil/src/main/native/cpp/uv/Process.cpp
index 90be6d5bed..f41f492a6c 100644
--- a/wpiutil/src/main/native/cpp/uv/Process.cpp
+++ b/wpiutil/src/main/native/cpp/uv/Process.cpp
@@ -10,7 +10,7 @@
 
 namespace wpi::uv {
 
-std::shared_ptr<Process> Process::SpawnArray(Loop& loop, const Twine& file,
+std::shared_ptr<Process> Process::SpawnArray(Loop& loop, std::string_view file,
                                              ArrayRef<Option> options) {
   // convert Option array to libuv structure
   uv_process_options_t coptions;
@@ -20,8 +20,8 @@ std::shared_ptr<Process> Process::SpawnArray(Loop& loop, const Twine& file,
     h.exited(status, signal);
   };
 
-  SmallString<128> fileBuf;
-  coptions.file = file.toNullTerminatedStringRef(fileBuf).data();
+  SmallString<128> fileBuf{file};
+  coptions.file = fileBuf.c_str();
   coptions.cwd = nullptr;
   coptions.flags = 0;
   coptions.uid = 0;
diff --git a/wpiutil/src/main/native/cpp/uv/Tcp.cpp b/wpiutil/src/main/native/cpp/uv/Tcp.cpp
index e02f1b659b..c1b3cbb120 100644
--- a/wpiutil/src/main/native/cpp/uv/Tcp.cpp
+++ b/wpiutil/src/main/native/cpp/uv/Tcp.cpp
@@ -61,7 +61,7 @@ Tcp* Tcp::DoAccept() {
   return Accept().get();
 }
 
-void Tcp::Bind(const Twine& ip, unsigned int port, unsigned int flags) {
+void Tcp::Bind(std::string_view ip, unsigned int port, unsigned int flags) {
   sockaddr_in addr;
   int err = NameToAddr(ip, port, &addr);
   if (err < 0) {
@@ -71,7 +71,7 @@ void Tcp::Bind(const Twine& ip, unsigned int port, unsigned int flags) {
   }
 }
 
-void Tcp::Bind6(const Twine& ip, unsigned int port, unsigned int flags) {
+void Tcp::Bind6(std::string_view ip, unsigned int port, unsigned int flags) {
   sockaddr_in6 addr;
   int err = NameToAddr(ip, port, &addr);
   if (err < 0) {
@@ -123,7 +123,7 @@ void Tcp::Connect(const sockaddr& addr, std::function<void()> callback) {
   Connect(addr, req);
 }
 
-void Tcp::Connect(const Twine& ip, unsigned int port,
+void Tcp::Connect(std::string_view ip, unsigned int port,
                   const std::shared_ptr<TcpConnectReq>& req) {
   sockaddr_in addr;
   int err = NameToAddr(ip, port, &addr);
@@ -134,7 +134,7 @@ void Tcp::Connect(const Twine& ip, unsigned int port,
   }
 }
 
-void Tcp::Connect(const Twine& ip, unsigned int port,
+void Tcp::Connect(std::string_view ip, unsigned int port,
                   std::function<void()> callback) {
   sockaddr_in addr;
   int err = NameToAddr(ip, port, &addr);
@@ -145,7 +145,7 @@ void Tcp::Connect(const Twine& ip, unsigned int port,
   }
 }
 
-void Tcp::Connect6(const Twine& ip, unsigned int port,
+void Tcp::Connect6(std::string_view ip, unsigned int port,
                    const std::shared_ptr<TcpConnectReq>& req) {
   sockaddr_in6 addr;
   int err = NameToAddr(ip, port, &addr);
@@ -156,7 +156,7 @@ void Tcp::Connect6(const Twine& ip, unsigned int port,
   }
 }
 
-void Tcp::Connect6(const Twine& ip, unsigned int port,
+void Tcp::Connect6(std::string_view ip, unsigned int port,
                    std::function<void()> callback) {
   sockaddr_in6 addr;
   int err = NameToAddr(ip, port, &addr);
diff --git a/wpiutil/src/main/native/cpp/uv/Udp.cpp b/wpiutil/src/main/native/cpp/uv/Udp.cpp
index 715f5cb3fd..130a417e3f 100644
--- a/wpiutil/src/main/native/cpp/uv/Udp.cpp
+++ b/wpiutil/src/main/native/cpp/uv/Udp.cpp
@@ -47,7 +47,7 @@ std::shared_ptr<Udp> Udp::Create(Loop& loop, unsigned int flags) {
   return h;
 }
 
-void Udp::Bind(const Twine& ip, unsigned int port, unsigned int flags) {
+void Udp::Bind(std::string_view ip, unsigned int port, unsigned int flags) {
   sockaddr_in addr;
   int err = NameToAddr(ip, port, &addr);
   if (err < 0) {
@@ -57,7 +57,7 @@ void Udp::Bind(const Twine& ip, unsigned int port, unsigned int flags) {
   }
 }
 
-void Udp::Bind6(const Twine& ip, unsigned int port, unsigned int flags) {
+void Udp::Bind6(std::string_view ip, unsigned int port, unsigned int flags) {
   sockaddr_in6 addr;
   int err = NameToAddr(ip, port, &addr);
   if (err < 0) {
@@ -67,7 +67,7 @@ void Udp::Bind6(const Twine& ip, unsigned int port, unsigned int flags) {
   }
 }
 
-void Udp::Connect(const Twine& ip, unsigned int port) {
+void Udp::Connect(std::string_view ip, unsigned int port) {
   sockaddr_in addr;
   int err = NameToAddr(ip, port, &addr);
   if (err < 0) {
@@ -77,7 +77,7 @@ void Udp::Connect(const Twine& ip, unsigned int port) {
   }
 }
 
-void Udp::Connect6(const Twine& ip, unsigned int port) {
+void Udp::Connect6(std::string_view ip, unsigned int port) {
   sockaddr_in6 addr;
   int err = NameToAddr(ip, port, &addr);
   if (err < 0) {
@@ -107,20 +107,18 @@ sockaddr_storage Udp::GetSock() {
   return name;
 }
 
-void Udp::SetMembership(const Twine& multicastAddr, const Twine& interfaceAddr,
+void Udp::SetMembership(std::string_view multicastAddr,
+                        std::string_view interfaceAddr,
                         uv_membership membership) {
-  SmallString<128> multicastAddrBuf;
-  SmallString<128> interfaceAddrBuf;
-  Invoke(&uv_udp_set_membership, GetRaw(),
-         multicastAddr.toNullTerminatedStringRef(multicastAddrBuf).data(),
-         interfaceAddr.toNullTerminatedStringRef(interfaceAddrBuf).data(),
-         membership);
+  SmallString<128> multicastAddrBuf{multicastAddr};
+  SmallString<128> interfaceAddrBuf{interfaceAddr};
+  Invoke(&uv_udp_set_membership, GetRaw(), multicastAddrBuf.c_str(),
+         interfaceAddrBuf.c_str(), membership);
 }
 
-void Udp::SetMulticastInterface(const Twine& interfaceAddr) {
-  SmallString<128> interfaceAddrBuf;
-  Invoke(&uv_udp_set_multicast_interface, GetRaw(),
-         interfaceAddr.toNullTerminatedStringRef(interfaceAddrBuf).data());
+void Udp::SetMulticastInterface(std::string_view interfaceAddr) {
+  SmallString<128> interfaceAddrBuf{interfaceAddr};
+  Invoke(&uv_udp_set_multicast_interface, GetRaw(), interfaceAddrBuf.c_str());
 }
 
 void Udp::Send(const sockaddr& addr, ArrayRef<Buffer> bufs,
diff --git a/wpiutil/src/main/native/include/wpi/Base64.h b/wpiutil/src/main/native/include/wpi/Base64.h
index cc5531d6a7..bea6e18fb4 100644
--- a/wpiutil/src/main/native/include/wpi/Base64.h
+++ b/wpiutil/src/main/native/include/wpi/Base64.h
@@ -7,26 +7,26 @@
 
 #include <cstddef>
 #include <string>
-
-#include "wpi/StringRef.h"
+#include <string_view>
 
 namespace wpi {
 template <typename T>
 class SmallVectorImpl;
 class raw_ostream;
 
-size_t Base64Decode(raw_ostream& os, StringRef encoded);
+size_t Base64Decode(raw_ostream& os, std::string_view encoded);
 
-size_t Base64Decode(StringRef encoded, std::string* plain);
+size_t Base64Decode(std::string_view encoded, std::string* plain);
 
-StringRef Base64Decode(StringRef encoded, size_t* num_read,
-                       SmallVectorImpl<char>& buf);
+std::string_view Base64Decode(std::string_view encoded, size_t* num_read,
+                              SmallVectorImpl<char>& buf);
 
-void Base64Encode(raw_ostream& os, StringRef plain);
+void Base64Encode(raw_ostream& os, std::string_view plain);
 
-void Base64Encode(StringRef plain, std::string* encoded);
+void Base64Encode(std::string_view plain, std::string* encoded);
 
-StringRef Base64Encode(StringRef plain, SmallVectorImpl<char>& buf);
+std::string_view Base64Encode(std::string_view plain,
+                              SmallVectorImpl<char>& buf);
 
 }  // namespace wpi
 
diff --git a/wpiutil/src/main/native/include/wpi/ConvertUTF.h b/wpiutil/src/main/native/include/wpi/ConvertUTF.h
index a9bdb606b4..99aac6a89b 100644
--- a/wpiutil/src/main/native/include/wpi/ConvertUTF.h
+++ b/wpiutil/src/main/native/include/wpi/ConvertUTF.h
@@ -91,10 +91,10 @@
 #define LLVM_SUPPORT_CONVERTUTF_H
 
 #include "wpi/ArrayRef.h"
-#include "wpi/StringRef.h"
 
 #include <cstddef>
 #include <string>
+#include <string_view>
 #include <system_error>
 
 // Wrap everything in namespace wpi so that programs can link with wpiutil and
@@ -243,15 +243,15 @@ bool convertUTF16ToUTF8String(ArrayRef<UTF16> SrcUTF16,
  *
  * \returns true on success
  */
-bool convertUTF8ToUTF16String(StringRef SrcUTF8,
+bool convertUTF8ToUTF16String(std::string_view SrcUTF8,
                               SmallVectorImpl<UTF16> &DstUTF16);
 
 #if defined(_WIN32)
 namespace sys {
 namespace windows {
-std::error_code UTF8ToUTF16(StringRef utf8, SmallVectorImpl<wchar_t> &utf16);
+std::error_code UTF8ToUTF16(std::string_view utf8, SmallVectorImpl<wchar_t> &utf16);
 /// Convert to UTF16 from the current code page used in the system
-std::error_code CurCPToUTF16(StringRef utf8, SmallVectorImpl<wchar_t> &utf16);
+std::error_code CurCPToUTF16(std::string_view utf8, SmallVectorImpl<wchar_t> &utf16);
 std::error_code UTF16ToUTF8(const wchar_t *utf16, size_t utf16_len,
                             SmallVectorImpl<char> &utf8);
 /// Convert from UTF16 to the current code page used in the system
diff --git a/wpiutil/src/main/native/include/wpi/Demangle.h b/wpiutil/src/main/native/include/wpi/Demangle.h
index 13d8cf1d71..03a7d3f254 100644
--- a/wpiutil/src/main/native/include/wpi/Demangle.h
+++ b/wpiutil/src/main/native/include/wpi/Demangle.h
@@ -6,8 +6,7 @@
 #define WPIUTIL_WPI_DEMANGLE_H_
 
 #include <string>
-
-#include "wpi/Twine.h"
+#include <string_view>
 
 namespace wpi {
 
@@ -17,7 +16,7 @@ namespace wpi {
  * @param mangledSymbol the mangled symbol.
  * @return The demangled symbol, or mangledSymbol if demangling fails.
  */
-std::string Demangle(const Twine& mangledSymbol);
+std::string Demangle(std::string_view mangledSymbol);
 
 }  // namespace wpi
 
diff --git a/wpiutil/src/main/native/include/wpi/DenseMapInfo.h b/wpiutil/src/main/native/include/wpi/DenseMapInfo.h
index 81ccdc710b..f6b1d4b7c0 100644
--- a/wpiutil/src/main/native/include/wpi/DenseMapInfo.h
+++ b/wpiutil/src/main/native/include/wpi/DenseMapInfo.h
@@ -16,11 +16,11 @@
 
 #include "wpi/ArrayRef.h"
 #include "wpi/Hashing.h"
-#include "wpi/StringRef.h"
 #include "wpi/PointerLikeTypeTraits.h"
 #include <cassert>
 #include <cstddef>
 #include <cstdint>
+#include <string_view>
 #include <utility>
 
 namespace wpi {
@@ -206,26 +206,26 @@ struct DenseMapInfo<std::pair<T, U>> {
   }
 };
 
-// Provide DenseMapInfo for StringRefs.
-template <> struct DenseMapInfo<StringRef> {
-  static inline StringRef getEmptyKey() {
-    return StringRef(reinterpret_cast<const char *>(~static_cast<uintptr_t>(0)),
+// Provide DenseMapInfo for std::string_view.
+template <> struct DenseMapInfo<std::string_view> {
+  static inline std::string_view getEmptyKey() {
+    return std::string_view(reinterpret_cast<const char *>(~static_cast<uintptr_t>(0)),
                      0);
   }
 
-  static inline StringRef getTombstoneKey() {
-    return StringRef(reinterpret_cast<const char *>(~static_cast<uintptr_t>(1)),
+  static inline std::string_view getTombstoneKey() {
+    return std::string_view(reinterpret_cast<const char *>(~static_cast<uintptr_t>(1)),
                      0);
   }
 
-  static unsigned getHashValue(StringRef Val) {
+  static unsigned getHashValue(std::string_view Val) {
     assert(Val.data() != getEmptyKey().data() && "Cannot hash the empty key!");
     assert(Val.data() != getTombstoneKey().data() &&
            "Cannot hash the tombstone key!");
     return (unsigned)(hash_value(Val));
   }
 
-  static bool isEqual(StringRef LHS, StringRef RHS) {
+  static bool isEqual(std::string_view LHS, std::string_view RHS) {
     if (RHS.data() == getEmptyKey().data())
       return LHS.data() == getEmptyKey().data();
     if (RHS.data() == getTombstoneKey().data())
diff --git a/wpiutil/src/main/native/include/wpi/Error.h b/wpiutil/src/main/native/include/wpi/Error.h
deleted file mode 100644
index c0f1781acb..0000000000
--- a/wpiutil/src/main/native/include/wpi/Error.h
+++ /dev/null
@@ -1,1187 +0,0 @@
-//===- llvm/Support/Error.h - Recoverable error handling --------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file defines an API used to report recoverable errors.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef WPIUTIL_WPI_ERROR_H
-#define WPIUTIL_WPI_ERROR_H
-
-#include "wpi/STLExtras.h"
-#include "wpi/SmallVector.h"
-#include "wpi/StringExtras.h"
-#include "wpi/Twine.h"
-#include "wpi/AlignOf.h"
-#include "wpi/Compiler.h"
-#include "wpi/ErrorHandling.h"
-#include "wpi/ErrorOr.h"
-#include "wpi/Format.h"
-#include "wpi/raw_ostream.h"
-#include <algorithm>
-#include <cassert>
-#include <cstdint>
-#include <cstdlib>
-#include <functional>
-#include <memory>
-#include <new>
-#include <string>
-#include <system_error>
-#include <type_traits>
-#include <utility>
-#include <vector>
-
-namespace wpi {
-
-class ErrorSuccess;
-
-/// Base class for error info classes. Do not extend this directly: Extend
-/// the ErrorInfo template subclass instead.
-class ErrorInfoBase {
-public:
-  virtual ~ErrorInfoBase() = default;
-
-  /// Print an error message to an output stream.
-  virtual void log(raw_ostream &OS) const = 0;
-
-  /// Return the error message as a string.
-  virtual std::string message() const {
-    std::string Msg;
-    raw_string_ostream OS(Msg);
-    log(OS);
-    return OS.str();
-  }
-
-  /// Convert this error to a std::error_code.
-  ///
-  /// This is a temporary crutch to enable interaction with code still
-  /// using std::error_code. It will be removed in the future.
-  virtual std::error_code convertToErrorCode() const = 0;
-
-  // Returns the class ID for this type.
-  static const void *classID() { return &ID; }
-
-  // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
-  virtual const void *dynamicClassID() const = 0;
-
-  // Check whether this instance is a subclass of the class identified by
-  // ClassID.
-  virtual bool isA(const void *const ClassID) const {
-    return ClassID == classID();
-  }
-
-  // Check whether this instance is a subclass of ErrorInfoT.
-  template <typename ErrorInfoT> bool isA() const {
-    return isA(ErrorInfoT::classID());
-  }
-
-private:
-  virtual void anchor();
-
-  static char ID;
-};
-
-/// Lightweight error class with error context and mandatory checking.
-///
-/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
-/// are represented by setting the pointer to a ErrorInfoBase subclass
-/// instance containing information describing the failure. Success is
-/// represented by a null pointer value.
-///
-/// Instances of Error also contains a 'Checked' flag, which must be set
-/// before the destructor is called, otherwise the destructor will trigger a
-/// runtime error. This enforces at runtime the requirement that all Error
-/// instances be checked or returned to the caller.
-///
-/// There are two ways to set the checked flag, depending on what state the
-/// Error instance is in. For Error instances indicating success, it
-/// is sufficient to invoke the boolean conversion operator. E.g.:
-///
-///   @code{.cpp}
-///   Error foo(<...>);
-///
-///   if (auto E = foo(<...>))
-///     return E; // <- Return E if it is in the error state.
-///   // We have verified that E was in the success state. It can now be safely
-///   // destroyed.
-///   @endcode
-///
-/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
-/// without testing the return value will raise a runtime error, even if foo
-/// returns success.
-///
-/// For Error instances representing failure, you must use either the
-/// handleErrors or handleAllErrors function with a typed handler. E.g.:
-///
-///   @code{.cpp}
-///   class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
-///     // Custom error info.
-///   };
-///
-///   Error foo(<...>) { return make_error<MyErrorInfo>(...); }
-///
-///   auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
-///   auto NewE =
-///     handleErrors(E,
-///       [](const MyErrorInfo &M) {
-///         // Deal with the error.
-///       },
-///       [](std::unique_ptr<OtherError> M) -> Error {
-///         if (canHandle(*M)) {
-///           // handle error.
-///           return Error::success();
-///         }
-///         // Couldn't handle this error instance. Pass it up the stack.
-///         return Error(std::move(M));
-///       );
-///   // Note - we must check or return NewE in case any of the handlers
-///   // returned a new error.
-///   @endcode
-///
-/// The handleAllErrors function is identical to handleErrors, except
-/// that it has a void return type, and requires all errors to be handled and
-/// no new errors be returned. It prevents errors (assuming they can all be
-/// handled) from having to be bubbled all the way to the top-level.
-///
-/// *All* Error instances must be checked before destruction, even if
-/// they're moved-assigned or constructed from Success values that have already
-/// been checked. This enforces checking through all levels of the call stack.
-class LLVM_NODISCARD Error {
-  // Both ErrorList and FileError need to be able to yank ErrorInfoBase
-  // pointers out of this class to add to the error list.
-  friend class ErrorList;
-  friend class FileError;
-
-  // handleErrors needs to be able to set the Checked flag.
-  template <typename... HandlerTs>
-  friend Error handleErrors(Error E, HandlerTs &&... Handlers);
-
-  // Expected<T> needs to be able to steal the payload when constructed from an
-  // error.
-  template <typename T> friend class Expected;
-
-protected:
-  /// Create a success value. Prefer using 'Error::success()' for readability
-  Error() {
-    setPtr(nullptr);
-    setChecked(false);
-  }
-
-public:
-  /// Create a success value.
-  static ErrorSuccess success();
-
-  // Errors are not copy-constructable.
-  Error(const Error &Other) = delete;
-
-  /// Move-construct an error value. The newly constructed error is considered
-  /// unchecked, even if the source error had been checked. The original error
-  /// becomes a checked Success value, regardless of its original state.
-  Error(Error &&Other) noexcept {
-    setChecked(true);
-    *this = std::move(Other);
-  }
-
-  /// Create an error value. Prefer using the 'make_error' function, but
-  /// this constructor can be useful when "re-throwing" errors from handlers.
-  Error(std::unique_ptr<ErrorInfoBase> Payload) {
-    setPtr(Payload.release());
-    setChecked(false);
-  }
-
-  // Errors are not copy-assignable.
-  Error &operator=(const Error &Other) = delete;
-
-  /// Move-assign an error value. The current error must represent success, you
-  /// you cannot overwrite an unhandled error. The current error is then
-  /// considered unchecked. The source error becomes a checked success value,
-  /// regardless of its original state.
-  Error &operator=(Error &&Other) noexcept {
-    // Don't allow overwriting of unchecked values.
-    assertIsChecked();
-    setPtr(Other.getPtr());
-
-    // This Error is unchecked, even if the source error was checked.
-    setChecked(false);
-
-    // Null out Other's payload and set its checked bit.
-    Other.setPtr(nullptr);
-    Other.setChecked(true);
-
-    return *this;
-  }
-
-  /// Destroy a Error. Fails with a call to abort() if the error is
-  /// unchecked.
-  ~Error() {
-    assertIsChecked();
-    delete getPtr();
-  }
-
-  /// Bool conversion. Returns true if this Error is in a failure state,
-  /// and false if it is in an accept state. If the error is in a Success state
-  /// it will be considered checked.
-  explicit operator bool() {
-    setChecked(getPtr() == nullptr);
-    return getPtr() != nullptr;
-  }
-
-  /// Check whether one error is a subclass of another.
-  template <typename ErrT> bool isA() const {
-    return getPtr() && getPtr()->isA(ErrT::classID());
-  }
-
-  /// Returns the dynamic class id of this error, or null if this is a success
-  /// value.
-  const void* dynamicClassID() const {
-    if (!getPtr())
-      return nullptr;
-    return getPtr()->dynamicClassID();
-  }
-
-private:
-  void assertIsChecked() {
-  }
-
-  ErrorInfoBase *getPtr() const {
-    return reinterpret_cast<ErrorInfoBase*>(
-             reinterpret_cast<uintptr_t>(Payload) &
-             ~static_cast<uintptr_t>(0x1));
-  }
-
-  void setPtr(ErrorInfoBase *EI) {
-    Payload = EI;
-  }
-
-  bool getChecked() const {
-    return true;
-  }
-
-  void setChecked(bool V) {
-    Payload = reinterpret_cast<ErrorInfoBase*>(
-                (reinterpret_cast<uintptr_t>(Payload) &
-                  ~static_cast<uintptr_t>(0x1)) |
-                  (V ? 0 : 1));
-  }
-
-  std::unique_ptr<ErrorInfoBase> takePayload() {
-    std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
-    setPtr(nullptr);
-    setChecked(true);
-    return Tmp;
-  }
-
-  friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
-    if (auto P = E.getPtr())
-      P->log(OS);
-    else
-      OS << "success";
-    return OS;
-  }
-
-  ErrorInfoBase *Payload = nullptr;
-};
-
-/// Subclass of Error for the sole purpose of identifying the success path in
-/// the type system. This allows to catch invalid conversion to Expected<T> at
-/// compile time.
-class ErrorSuccess final : public Error {};
-
-inline ErrorSuccess Error::success() { return ErrorSuccess(); }
-
-/// Make a Error instance representing failure using the given error info
-/// type.
-template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
-  return Error(std::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
-}
-
-/// Base class for user error types. Users should declare their error types
-/// like:
-///
-/// class MyError : public ErrorInfo<MyError> {
-///   ....
-/// };
-///
-/// This class provides an implementation of the ErrorInfoBase::kind
-/// method, which is used by the Error RTTI system.
-template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
-class ErrorInfo : public ParentErrT {
-public:
-  using ParentErrT::ParentErrT; // inherit constructors
-
-  static const void *classID() { return &ThisErrT::ID; }
-
-  const void *dynamicClassID() const override { return &ThisErrT::ID; }
-
-  bool isA(const void *const ClassID) const override {
-    return ClassID == classID() || ParentErrT::isA(ClassID);
-  }
-};
-
-/// Special ErrorInfo subclass representing a list of ErrorInfos.
-/// Instances of this class are constructed by joinError.
-class ErrorList final : public ErrorInfo<ErrorList> {
-  // handleErrors needs to be able to iterate the payload list of an
-  // ErrorList.
-  template <typename... HandlerTs>
-  friend Error handleErrors(Error E, HandlerTs &&... Handlers);
-
-  // joinErrors is implemented in terms of join.
-  friend Error joinErrors(Error, Error);
-
-public:
-  void log(raw_ostream &OS) const override {
-    OS << "Multiple errors:\n";
-    for (auto &ErrPayload : Payloads) {
-      ErrPayload->log(OS);
-      OS << "\n";
-    }
-  }
-
-  std::error_code convertToErrorCode() const override;
-
-  // Used by ErrorInfo::classID.
-  static char ID;
-
-private:
-  ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
-            std::unique_ptr<ErrorInfoBase> Payload2) {
-    assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&
-           "ErrorList constructor payloads should be singleton errors");
-    Payloads.push_back(std::move(Payload1));
-    Payloads.push_back(std::move(Payload2));
-  }
-
-  static Error join(Error E1, Error E2) {
-    if (!E1)
-      return E2;
-    if (!E2)
-      return E1;
-    if (E1.isA<ErrorList>()) {
-      auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
-      if (E2.isA<ErrorList>()) {
-        auto E2Payload = E2.takePayload();
-        auto &E2List = static_cast<ErrorList &>(*E2Payload);
-        for (auto &Payload : E2List.Payloads)
-          E1List.Payloads.push_back(std::move(Payload));
-      } else
-        E1List.Payloads.push_back(E2.takePayload());
-
-      return E1;
-    }
-    if (E2.isA<ErrorList>()) {
-      auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
-      E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
-      return E2;
-    }
-    return Error(std::unique_ptr<ErrorList>(
-        new ErrorList(E1.takePayload(), E2.takePayload())));
-  }
-
-  std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
-};
-
-/// Concatenate errors. The resulting Error is unchecked, and contains the
-/// ErrorInfo(s), if any, contained in E1, followed by the
-/// ErrorInfo(s), if any, contained in E2.
-inline Error joinErrors(Error E1, Error E2) {
-  return ErrorList::join(std::move(E1), std::move(E2));
-}
-
-/// Tagged union holding either a T or a Error.
-///
-/// This class parallels ErrorOr, but replaces error_code with Error. Since
-/// Error cannot be copied, this class replaces getError() with
-/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
-/// error class type.
-template <class T> class LLVM_NODISCARD Expected {
-  template <class T1> friend class ExpectedAsOutParameter;
-  template <class OtherT> friend class Expected;
-
-  static const bool isRef = std::is_reference<T>::value;
-
-  using wrap = std::reference_wrapper<typename std::remove_reference<T>::type>;
-
-  using error_type = std::unique_ptr<ErrorInfoBase>;
-
-public:
-  using storage_type = typename std::conditional<isRef, wrap, T>::type;
-  using value_type = T;
-
-private:
-  using reference = typename std::remove_reference<T>::type &;
-  using const_reference = const typename std::remove_reference<T>::type &;
-  using pointer = typename std::remove_reference<T>::type *;
-  using const_pointer = const typename std::remove_reference<T>::type *;
-
-public:
-  /// Create an Expected<T> error value from the given Error.
-  Expected(Error Err)
-      : HasError(true)
-  {
-    assert(Err && "Cannot create Expected<T> from Error success value.");
-    new (getErrorStorage()) error_type(Err.takePayload());
-  }
-
-  /// Forbid to convert from Error::success() implicitly, this avoids having
-  /// Expected<T> foo() { return Error::success(); } which compiles otherwise
-  /// but triggers the assertion above.
-  Expected(ErrorSuccess) = delete;
-
-  /// Create an Expected<T> success value from the given OtherT value, which
-  /// must be convertible to T.
-  template <typename OtherT>
-  Expected(OtherT &&Val,
-           typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
-               * = nullptr)
-      : HasError(false)
-  {
-    new (getStorage()) storage_type(std::forward<OtherT>(Val));
-  }
-
-  /// Move construct an Expected<T> value.
-  Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
-
-  /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
-  /// must be convertible to T.
-  template <class OtherT>
-  Expected(Expected<OtherT> &&Other,
-           typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
-               * = nullptr) {
-    moveConstruct(std::move(Other));
-  }
-
-  /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
-  /// isn't convertible to T.
-  template <class OtherT>
-  explicit Expected(
-      Expected<OtherT> &&Other,
-      typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
-          nullptr) {
-    moveConstruct(std::move(Other));
-  }
-
-  /// Move-assign from another Expected<T>.
-  Expected &operator=(Expected &&Other) {
-    moveAssign(std::move(Other));
-    return *this;
-  }
-
-  /// Destroy an Expected<T>.
-  ~Expected() {
-    assertIsChecked();
-    if (!HasError)
-      getStorage()->~storage_type();
-    else
-      getErrorStorage()->~error_type();
-  }
-
-  /// Return false if there is an error.
-  explicit operator bool() {
-    return !HasError;
-  }
-
-  /// Returns a reference to the stored T value.
-  reference get() {
-    assertIsChecked();
-    return *getStorage();
-  }
-
-  /// Returns a const reference to the stored T value.
-  const_reference get() const {
-    assertIsChecked();
-    return const_cast<Expected<T> *>(this)->get();
-  }
-
-  /// Check that this Expected<T> is an error of type ErrT.
-  template <typename ErrT> bool errorIsA() const {
-    return HasError && (*getErrorStorage())->template isA<ErrT>();
-  }
-
-  /// Take ownership of the stored error.
-  /// After calling this the Expected<T> is in an indeterminate state that can
-  /// only be safely destructed. No further calls (beside the destructor) should
-  /// be made on the Expected<T> vaule.
-  Error takeError() {
-    return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
-  }
-
-  /// Returns a pointer to the stored T value.
-  pointer operator->() {
-    assertIsChecked();
-    return toPointer(getStorage());
-  }
-
-  /// Returns a const pointer to the stored T value.
-  const_pointer operator->() const {
-    assertIsChecked();
-    return toPointer(getStorage());
-  }
-
-  /// Returns a reference to the stored T value.
-  reference operator*() {
-    assertIsChecked();
-    return *getStorage();
-  }
-
-  /// Returns a const reference to the stored T value.
-  const_reference operator*() const {
-    assertIsChecked();
-    return *getStorage();
-  }
-
-private:
-  template <class T1>
-  static bool compareThisIfSameType(const T1 &a, const T1 &b) {
-    return &a == &b;
-  }
-
-  template <class T1, class T2>
-  static bool compareThisIfSameType(const T1 &a, const T2 &b) {
-    return false;
-  }
-
-  template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
-    HasError = Other.HasError;
-
-    if (!HasError)
-      new (getStorage()) storage_type(std::move(*Other.getStorage()));
-    else
-      new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
-  }
-
-  template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
-    assertIsChecked();
-
-    if (compareThisIfSameType(*this, Other))
-      return;
-
-    this->~Expected();
-    new (this) Expected(std::move(Other));
-  }
-
-  pointer toPointer(pointer Val) { return Val; }
-
-  const_pointer toPointer(const_pointer Val) const { return Val; }
-
-  pointer toPointer(wrap *Val) { return &Val->get(); }
-
-  const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
-
-  storage_type *getStorage() {
-    assert(!HasError && "Cannot get value when an error exists!");
-    return reinterpret_cast<storage_type *>(TStorage.buffer);
-  }
-
-  const storage_type *getStorage() const {
-    assert(!HasError && "Cannot get value when an error exists!");
-    return reinterpret_cast<const storage_type *>(TStorage.buffer);
-  }
-
-  error_type *getErrorStorage() {
-    assert(HasError && "Cannot get error when a value exists!");
-    return reinterpret_cast<error_type *>(ErrorStorage.buffer);
-  }
-
-  const error_type *getErrorStorage() const {
-    assert(HasError && "Cannot get error when a value exists!");
-    return reinterpret_cast<const error_type *>(ErrorStorage.buffer);
-  }
-
-  // Used by ExpectedAsOutParameter to reset the checked flag.
-  void setUnchecked() {
-  }
-
-  void assertIsChecked() {
-  }
-
-  union {
-    AlignedCharArrayUnion<storage_type> TStorage;
-    AlignedCharArrayUnion<error_type> ErrorStorage;
-  };
-  bool HasError : 1;
-};
-
-/// Report a serious error, calling any installed error handler. See
-/// ErrorHandling.h.
-LLVM_ATTRIBUTE_NORETURN void report_fatal_error(Error Err,
-                                                bool gen_crash_diag = true);
-
-/// Report a fatal error if Err is a failure value.
-///
-/// This function can be used to wrap calls to fallible functions ONLY when it
-/// is known that the Error will always be a success value. E.g.
-///
-///   @code{.cpp}
-///   // foo only attempts the fallible operation if DoFallibleOperation is
-///   // true. If DoFallibleOperation is false then foo always returns
-///   // Error::success().
-///   Error foo(bool DoFallibleOperation);
-///
-///   cantFail(foo(false));
-///   @endcode
-inline void cantFail(Error Err, const char *Msg = nullptr) {
-  if (Err) {
-    if (!Msg)
-      Msg = "Failure value returned from cantFail wrapped call";
-    wpi_unreachable(Msg);
-  }
-}
-
-/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
-/// returns the contained value.
-///
-/// This function can be used to wrap calls to fallible functions ONLY when it
-/// is known that the Error will always be a success value. E.g.
-///
-///   @code{.cpp}
-///   // foo only attempts the fallible operation if DoFallibleOperation is
-///   // true. If DoFallibleOperation is false then foo always returns an int.
-///   Expected<int> foo(bool DoFallibleOperation);
-///
-///   int X = cantFail(foo(false));
-///   @endcode
-template <typename T>
-T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
-  if (ValOrErr)
-    return std::move(*ValOrErr);
-  else {
-    if (!Msg)
-      Msg = "Failure value returned from cantFail wrapped call";
-    wpi_unreachable(Msg);
-  }
-}
-
-/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
-/// returns the contained reference.
-///
-/// This function can be used to wrap calls to fallible functions ONLY when it
-/// is known that the Error will always be a success value. E.g.
-///
-///   @code{.cpp}
-///   // foo only attempts the fallible operation if DoFallibleOperation is
-///   // true. If DoFallibleOperation is false then foo always returns a Bar&.
-///   Expected<Bar&> foo(bool DoFallibleOperation);
-///
-///   Bar &X = cantFail(foo(false));
-///   @endcode
-template <typename T>
-T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
-  if (ValOrErr)
-    return *ValOrErr;
-  else {
-    if (!Msg)
-      Msg = "Failure value returned from cantFail wrapped call";
-    wpi_unreachable(Msg);
-  }
-}
-
-/// Helper for testing applicability of, and applying, handlers for
-/// ErrorInfo types.
-template <typename HandlerT>
-class ErrorHandlerTraits
-    : public ErrorHandlerTraits<decltype(
-          &std::remove_reference<HandlerT>::type::operator())> {};
-
-// Specialization functions of the form 'Error (const ErrT&)'.
-template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
-public:
-  static bool appliesTo(const ErrorInfoBase &E) {
-    return E.template isA<ErrT>();
-  }
-
-  template <typename HandlerT>
-  static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
-    assert(appliesTo(*E) && "Applying incorrect handler");
-    return H(static_cast<ErrT &>(*E));
-  }
-};
-
-// Specialization functions of the form 'void (const ErrT&)'.
-template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
-public:
-  static bool appliesTo(const ErrorInfoBase &E) {
-    return E.template isA<ErrT>();
-  }
-
-  template <typename HandlerT>
-  static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
-    assert(appliesTo(*E) && "Applying incorrect handler");
-    H(static_cast<ErrT &>(*E));
-    return Error::success();
-  }
-};
-
-/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
-template <typename ErrT>
-class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
-public:
-  static bool appliesTo(const ErrorInfoBase &E) {
-    return E.template isA<ErrT>();
-  }
-
-  template <typename HandlerT>
-  static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
-    assert(appliesTo(*E) && "Applying incorrect handler");
-    std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
-    return H(std::move(SubE));
-  }
-};
-
-/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
-template <typename ErrT>
-class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
-public:
-  static bool appliesTo(const ErrorInfoBase &E) {
-    return E.template isA<ErrT>();
-  }
-
-  template <typename HandlerT>
-  static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
-    assert(appliesTo(*E) && "Applying incorrect handler");
-    std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
-    H(std::move(SubE));
-    return Error::success();
-  }
-};
-
-// Specialization for member functions of the form 'RetT (const ErrT&)'.
-template <typename C, typename RetT, typename ErrT>
-class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
-    : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
-
-// Specialization for member functions of the form 'RetT (const ErrT&) const'.
-template <typename C, typename RetT, typename ErrT>
-class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
-    : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
-
-// Specialization for member functions of the form 'RetT (const ErrT&)'.
-template <typename C, typename RetT, typename ErrT>
-class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
-    : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
-
-// Specialization for member functions of the form 'RetT (const ErrT&) const'.
-template <typename C, typename RetT, typename ErrT>
-class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
-    : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
-
-/// Specialization for member functions of the form
-/// 'RetT (std::unique_ptr<ErrT>)'.
-template <typename C, typename RetT, typename ErrT>
-class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
-    : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
-
-/// Specialization for member functions of the form
-/// 'RetT (std::unique_ptr<ErrT>) const'.
-template <typename C, typename RetT, typename ErrT>
-class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
-    : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
-
-inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
-  return Error(std::move(Payload));
-}
-
-template <typename HandlerT, typename... HandlerTs>
-Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
-                      HandlerT &&Handler, HandlerTs &&... Handlers) {
-  if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
-    return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
-                                               std::move(Payload));
-  return handleErrorImpl(std::move(Payload),
-                         std::forward<HandlerTs>(Handlers)...);
-}
-
-/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
-/// unhandled errors (or Errors returned by handlers) are re-concatenated and
-/// returned.
-/// Because this function returns an error, its result must also be checked
-/// or returned. If you intend to handle all errors use handleAllErrors
-/// (which returns void, and will abort() on unhandled errors) instead.
-template <typename... HandlerTs>
-Error handleErrors(Error E, HandlerTs &&... Hs) {
-  if (!E)
-    return Error::success();
-
-  std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
-
-  if (Payload->isA<ErrorList>()) {
-    ErrorList &List = static_cast<ErrorList &>(*Payload);
-    Error R;
-    for (auto &P : List.Payloads)
-      R = ErrorList::join(
-          std::move(R),
-          handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
-    return R;
-  }
-
-  return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
-}
-
-/// Behaves the same as handleErrors, except that by contract all errors
-/// *must* be handled by the given handlers (i.e. there must be no remaining
-/// errors after running the handlers, or wpi_unreachable is called).
-template <typename... HandlerTs>
-void handleAllErrors(Error E, HandlerTs &&... Handlers) {
-  cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
-}
-
-/// Check that E is a non-error, then drop it.
-/// If E is an error, wpi_unreachable will be called.
-inline void handleAllErrors(Error E) {
-  cantFail(std::move(E));
-}
-
-/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
-///
-/// If the incoming value is a success value it is returned unmodified. If it
-/// is a failure value then it the contained error is passed to handleErrors.
-/// If handleErrors is able to handle the error then the RecoveryPath functor
-/// is called to supply the final result. If handleErrors is not able to
-/// handle all errors then the unhandled errors are returned.
-///
-/// This utility enables the follow pattern:
-///
-///   @code{.cpp}
-///   enum FooStrategy { Aggressive, Conservative };
-///   Expected<Foo> foo(FooStrategy S);
-///
-///   auto ResultOrErr =
-///     handleExpected(
-///       foo(Aggressive),
-///       []() { return foo(Conservative); },
-///       [](AggressiveStrategyError&) {
-///         // Implicitly conusme this - we'll recover by using a conservative
-///         // strategy.
-///       });
-///
-///   @endcode
-template <typename T, typename RecoveryFtor, typename... HandlerTs>
-Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
-                           HandlerTs &&... Handlers) {
-  if (ValOrErr)
-    return ValOrErr;
-
-  if (auto Err = handleErrors(ValOrErr.takeError(),
-                              std::forward<HandlerTs>(Handlers)...))
-    return std::move(Err);
-
-  return RecoveryPath();
-}
-
-/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
-/// will be printed before the first one is logged. A newline will be printed
-/// after each error.
-///
-/// This function is compatible with the helpers from Support/WithColor.h. You
-/// can pass any of them as the OS. Please consider using them instead of
-/// including 'error: ' in the ErrorBanner.
-///
-/// This is useful in the base level of your program to allow clean termination
-/// (allowing clean deallocation of resources, etc.), while reporting error
-/// information to the user.
-void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner = {});
-
-/// Consume a Error without doing anything. This method should be used
-/// only where an error can be considered a reasonable and expected return
-/// value.
-///
-/// Uses of this method are potentially indicative of design problems: If it's
-/// legitimate to do nothing while processing an "error", the error-producer
-/// might be more clearly refactored to return an Optional<T>.
-inline void consumeError(Error Err) {
-  handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
-}
-
-/// Helper for converting an Error to a bool.
-///
-/// This method returns true if Err is in an error state, or false if it is
-/// in a success state.  Puts Err in a checked state in both cases (unlike
-/// Error::operator bool(), which only does this for success states).
-inline bool errorToBool(Error Err) {
-  bool IsError = static_cast<bool>(Err);
-  if (IsError)
-    consumeError(std::move(Err));
-  return IsError;
-}
-
-/// Helper for Errors used as out-parameters.
-///
-/// This helper is for use with the Error-as-out-parameter idiom, where an error
-/// is passed to a function or method by reference, rather than being returned.
-/// In such cases it is helpful to set the checked bit on entry to the function
-/// so that the error can be written to (unchecked Errors abort on assignment)
-/// and clear the checked bit on exit so that clients cannot accidentally forget
-/// to check the result. This helper performs these actions automatically using
-/// RAII:
-///
-///   @code{.cpp}
-///   Result foo(Error &Err) {
-///     ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
-///     // <body of foo>
-///     // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
-///   }
-///   @endcode
-///
-/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
-/// used with optional Errors (Error pointers that are allowed to be null). If
-/// ErrorAsOutParameter took an Error reference, an instance would have to be
-/// created inside every condition that verified that Error was non-null. By
-/// taking an Error pointer we can just create one instance at the top of the
-/// function.
-class ErrorAsOutParameter {
-public:
-  ErrorAsOutParameter(Error *Err) : Err(Err) {
-    // Raise the checked bit if Err is success.
-    if (Err)
-      (void)!!*Err;
-  }
-
-  ~ErrorAsOutParameter() {
-    // Clear the checked bit.
-    if (Err && !*Err)
-      *Err = Error::success();
-  }
-
-private:
-  Error *Err;
-};
-
-/// Helper for Expected<T>s used as out-parameters.
-///
-/// See ErrorAsOutParameter.
-template <typename T>
-class ExpectedAsOutParameter {
-public:
-  ExpectedAsOutParameter(Expected<T> *ValOrErr)
-    : ValOrErr(ValOrErr) {
-    if (ValOrErr)
-      (void)!!*ValOrErr;
-  }
-
-  ~ExpectedAsOutParameter() {
-    if (ValOrErr)
-      ValOrErr->setUnchecked();
-  }
-
-private:
-  Expected<T> *ValOrErr;
-};
-
-/// This class wraps a std::error_code in a Error.
-///
-/// This is useful if you're writing an interface that returns a Error
-/// (or Expected) and you want to call code that still returns
-/// std::error_codes.
-class ECError : public ErrorInfo<ECError> {
-  friend Error errorCodeToError(std::error_code);
-
-  virtual void anchor() override;
-
-public:
-  void setErrorCode(std::error_code EC) { this->EC = EC; }
-  std::error_code convertToErrorCode() const override { return EC; }
-  void log(raw_ostream &OS) const override { OS << EC.message(); }
-
-  // Used by ErrorInfo::classID.
-  static char ID;
-
-protected:
-  ECError() = default;
-  ECError(std::error_code EC) : EC(EC) {}
-
-  std::error_code EC;
-};
-
-/// The value returned by this function can be returned from convertToErrorCode
-/// for Error values where no sensible translation to std::error_code exists.
-/// It should only be used in this situation, and should never be used where a
-/// sensible conversion to std::error_code is available, as attempts to convert
-/// to/from this error will result in a fatal error. (i.e. it is a programmatic
-///error to try to convert such a value).
-std::error_code inconvertibleErrorCode();
-
-/// Helper for converting an std::error_code to a Error.
-Error errorCodeToError(std::error_code EC);
-
-/// Helper for converting an ECError to a std::error_code.
-///
-/// This method requires that Err be Error() or an ECError, otherwise it
-/// will trigger a call to abort().
-std::error_code errorToErrorCode(Error Err);
-
-/// Convert an ErrorOr<T> to an Expected<T>.
-template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
-  if (auto EC = EO.getError())
-    return errorCodeToError(EC);
-  return std::move(*EO);
-}
-
-/// Convert an Expected<T> to an ErrorOr<T>.
-template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
-  if (auto Err = E.takeError())
-    return errorToErrorCode(std::move(Err));
-  return std::move(*E);
-}
-
-/// This class wraps a string in an Error.
-///
-/// StringError is useful in cases where the client is not expected to be able
-/// to consume the specific error message programmatically (for example, if the
-/// error message is to be presented to the user).
-///
-/// StringError can also be used when additional information is to be printed
-/// along with a error_code message. Depending on the constructor called, this
-/// class can either display:
-///    1. the error_code message (ECError behavior)
-///    2. a string
-///    3. the error_code message and a string
-///
-/// These behaviors are useful when subtyping is required; for example, when a
-/// specific library needs an explicit error type. In the example below,
-/// PDBError is derived from StringError:
-///
-///   @code{.cpp}
-///   Expected<int> foo() {
-///      return wpi::make_error<PDBError>(pdb_error_code::dia_failed_loading,
-///                                       "Additional information");
-///   }
-///   @endcode
-///
-class StringError : public ErrorInfo<StringError> {
-public:
-  static char ID;
-
-  // Prints EC + S and converts to EC
-  StringError(std::error_code EC, const Twine &S = Twine());
-
-  // Prints S and converts to EC
-  StringError(const Twine &S, std::error_code EC);
-
-  void log(raw_ostream &OS) const override;
-  std::error_code convertToErrorCode() const override;
-
-  const std::string &getMessage() const { return Msg; }
-
-private:
-  std::string Msg;
-  std::error_code EC;
-  const bool PrintMsgOnly = false;
-};
-
-/// Create formatted StringError object.
-template <typename... Ts>
-Error createStringError(std::error_code EC, char const *Fmt,
-                        const Ts &... Vals) {
-  std::string Buffer;
-  raw_string_ostream Stream(Buffer);
-  Stream << format(Fmt, Vals...);
-  return make_error<StringError>(Stream.str(), EC);
-}
-
-Error createStringError(std::error_code EC, char const *Msg);
-
-/// This class wraps a filename and another Error.
-///
-/// In some cases, an error needs to live along a 'source' name, in order to
-/// show more detailed information to the user.
-class FileError final : public ErrorInfo<FileError> {
-
-  friend Error createFileError(std::string, Error);
-
-public:
-  void log(raw_ostream &OS) const override {
-    assert(Err && !FileName.empty() && "Trying to log after takeError().");
-    OS << "'" << FileName << "': ";
-    Err->log(OS);
-  }
-
-  Error takeError() { return Error(std::move(Err)); }
-
-  std::error_code convertToErrorCode() const override;
-
-  // Used by ErrorInfo::classID.
-  static char ID;
-
-private:
-  FileError(std::string F, std::unique_ptr<ErrorInfoBase> E) {
-    assert(E && "Cannot create FileError from Error success value.");
-    assert(!F.empty() &&
-           "The file name provided to FileError must not be empty.");
-    FileName = F;
-    Err = std::move(E);
-  }
-
-  static Error build(std::string F, Error E) {
-    return Error(std::unique_ptr<FileError>(new FileError(F, E.takePayload())));
-  }
-
-  std::string FileName;
-  std::unique_ptr<ErrorInfoBase> Err;
-};
-
-/// Concatenate a source file path and/or name with an Error. The resulting
-/// Error is unchecked.
-inline Error createFileError(std::string F, Error E) {
-  return FileError::build(F, std::move(E));
-}
-
-Error createFileError(std::string F, ErrorSuccess) = delete;
-
-/// Helper for check-and-exit error handling.
-///
-/// For tool use only. NOT FOR USE IN LIBRARY CODE.
-///
-class ExitOnError {
-public:
-  /// Create an error on exit helper.
-  ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
-      : Banner(std::move(Banner)),
-        GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
-
-  /// Set the banner string for any errors caught by operator().
-  void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
-
-  /// Set the exit-code mapper function.
-  void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
-    this->GetExitCode = std::move(GetExitCode);
-  }
-
-  /// Check Err. If it's in a failure state log the error(s) and exit.
-  void operator()(Error Err) const { checkError(std::move(Err)); }
-
-  /// Check E. If it's in a success state then return the contained value. If
-  /// it's in a failure state log the error(s) and exit.
-  template <typename T> T operator()(Expected<T> &&E) const {
-    checkError(E.takeError());
-    return std::move(*E);
-  }
-
-  /// Check E. If it's in a success state then return the contained reference. If
-  /// it's in a failure state log the error(s) and exit.
-  template <typename T> T& operator()(Expected<T&> &&E) const {
-    checkError(E.takeError());
-    return *E;
-  }
-
-private:
-  void checkError(Error Err) const {
-    if (Err) {
-      int ExitCode = GetExitCode(Err);
-      logAllUnhandledErrors(std::move(Err), errs(), Banner);
-      exit(ExitCode);
-    }
-  }
-
-  std::string Banner;
-  std::function<int(const Error &)> GetExitCode;
-};
-
-} // end namespace wpi
-
-#endif // WPIUTIL_WPI_ERROR_H
diff --git a/wpiutil/src/main/native/include/wpi/ErrorHandling.h b/wpiutil/src/main/native/include/wpi/ErrorHandling.h
index 5c89c5eeea..da9af4b178 100644
--- a/wpiutil/src/main/native/include/wpi/ErrorHandling.h
+++ b/wpiutil/src/main/native/include/wpi/ErrorHandling.h
@@ -17,11 +17,9 @@
 
 #include "wpi/Compiler.h"
 #include <string>
+#include <string_view>
 
 namespace wpi {
-class StringRef;
-  class Twine;
-
   /// An error handler callback.
   typedef void (*fatal_error_handler_t)(void *user_data,
                                         const std::string& reason,
@@ -73,9 +71,7 @@ LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const char *reason,
                                                 bool gen_crash_diag = true);
 LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const std::string &reason,
                                                 bool gen_crash_diag = true);
-LLVM_ATTRIBUTE_NORETURN void report_fatal_error(StringRef reason,
-                                                bool gen_crash_diag = true);
-LLVM_ATTRIBUTE_NORETURN void report_fatal_error(const Twine &reason,
+LLVM_ATTRIBUTE_NORETURN void report_fatal_error(std::string_view reason,
                                                 bool gen_crash_diag = true);
 
 /// Installs a new bad alloc error handler that should be used whenever a
diff --git a/wpiutil/src/main/native/include/wpi/ErrorOr.h b/wpiutil/src/main/native/include/wpi/ErrorOr.h
deleted file mode 100644
index e1803fddae..0000000000
--- a/wpiutil/src/main/native/include/wpi/ErrorOr.h
+++ /dev/null
@@ -1,279 +0,0 @@
-//===- llvm/Support/ErrorOr.h - Error Smart Pointer -------------*- C++ -*-===//
-//
-//                             The LLVM Linker
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-///
-/// \file
-///
-/// Provides ErrorOr<T> smart pointer.
-///
-//===----------------------------------------------------------------------===//
-
-#ifndef WPIUTIL_WPI_ERROROR_H
-#define WPIUTIL_WPI_ERROROR_H
-
-#include "wpi/AlignOf.h"
-#include <cassert>
-#include <system_error>
-#include <type_traits>
-#include <utility>
-
-namespace wpi {
-
-/// Represents either an error or a value T.
-///
-/// ErrorOr<T> is a pointer-like class that represents the result of an
-/// operation. The result is either an error, or a value of type T. This is
-/// designed to emulate the usage of returning a pointer where nullptr indicates
-/// failure. However instead of just knowing that the operation failed, we also
-/// have an error_code and optional user data that describes why it failed.
-///
-/// It is used like the following.
-/// \code
-///   ErrorOr<Buffer> getBuffer();
-///
-///   auto buffer = getBuffer();
-///   if (error_code ec = buffer.getError())
-///     return ec;
-///   buffer->write("adena");
-/// \endcode
-///
-///
-/// Implicit conversion to bool returns true if there is a usable value. The
-/// unary * and -> operators provide pointer like access to the value. Accessing
-/// the value when there is an error has undefined behavior.
-///
-/// When T is a reference type the behavior is slightly different. The reference
-/// is held in a std::reference_wrapper<std::remove_reference<T>::type>, and
-/// there is special handling to make operator -> work as if T was not a
-/// reference.
-///
-/// T cannot be a rvalue reference.
-template<class T>
-class ErrorOr {
-  template <class OtherT> friend class ErrorOr;
-
-  static const bool isRef = std::is_reference<T>::value;
-
-  using wrap = std::reference_wrapper<typename std::remove_reference<T>::type>;
-
-public:
-  using storage_type = typename std::conditional<isRef, wrap, T>::type;
-
-private:
-  using reference = typename std::remove_reference<T>::type &;
-  using const_reference = const typename std::remove_reference<T>::type &;
-  using pointer = typename std::remove_reference<T>::type *;
-  using const_pointer = const typename std::remove_reference<T>::type *;
-
-public:
-  template <class E>
-  ErrorOr(E ErrorCode,
-          typename std::enable_if<std::is_error_code_enum<E>::value ||
-                                      std::is_error_condition_enum<E>::value,
-                                  void *>::type = nullptr)
-      : HasError(true) {
-    new (getErrorStorage()) std::error_code(make_error_code(ErrorCode));
-  }
-
-  ErrorOr(std::error_code EC) : HasError(true) {
-    new (getErrorStorage()) std::error_code(EC);
-  }
-
-  template <class OtherT>
-  ErrorOr(OtherT &&Val,
-          typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
-              * = nullptr)
-      : HasError(false) {
-    new (getStorage()) storage_type(std::forward<OtherT>(Val));
-  }
-
-  ErrorOr(const ErrorOr &Other) {
-    copyConstruct(Other);
-  }
-
-  template <class OtherT>
-  ErrorOr(
-      const ErrorOr<OtherT> &Other,
-      typename std::enable_if<std::is_convertible<OtherT, T>::value>::type * =
-          nullptr) {
-    copyConstruct(Other);
-  }
-
-  template <class OtherT>
-  explicit ErrorOr(
-      const ErrorOr<OtherT> &Other,
-      typename std::enable_if<
-          !std::is_convertible<OtherT, const T &>::value>::type * = nullptr) {
-    copyConstruct(Other);
-  }
-
-  ErrorOr(ErrorOr &&Other) {
-    moveConstruct(std::move(Other));
-  }
-
-  template <class OtherT>
-  ErrorOr(
-      ErrorOr<OtherT> &&Other,
-      typename std::enable_if<std::is_convertible<OtherT, T>::value>::type * =
-          nullptr) {
-    moveConstruct(std::move(Other));
-  }
-
-  // This might eventually need SFINAE but it's more complex than is_convertible
-  // & I'm too lazy to write it right now.
-  template <class OtherT>
-  explicit ErrorOr(
-      ErrorOr<OtherT> &&Other,
-      typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
-          nullptr) {
-    moveConstruct(std::move(Other));
-  }
-
-  ErrorOr &operator=(const ErrorOr &Other) {
-    copyAssign(Other);
-    return *this;
-  }
-
-  ErrorOr &operator=(ErrorOr &&Other) {
-    moveAssign(std::move(Other));
-    return *this;
-  }
-
-  ~ErrorOr() {
-    if (!HasError)
-      getStorage()->~storage_type();
-  }
-
-  /// Return false if there is an error.
-  explicit operator bool() const {
-    return !HasError;
-  }
-
-  reference get() { return *getStorage(); }
-  const_reference get() const { return const_cast<ErrorOr<T> *>(this)->get(); }
-
-  std::error_code getError() const {
-    return HasError ? *getErrorStorage() : std::error_code();
-  }
-
-  pointer operator ->() {
-    return toPointer(getStorage());
-  }
-
-  const_pointer operator->() const { return toPointer(getStorage()); }
-
-  reference operator *() {
-    return *getStorage();
-  }
-
-  const_reference operator*() const { return *getStorage(); }
-
-private:
-  template <class OtherT>
-  void copyConstruct(const ErrorOr<OtherT> &Other) {
-    if (!Other.HasError) {
-      // Get the other value.
-      HasError = false;
-      new (getStorage()) storage_type(*Other.getStorage());
-    } else {
-      // Get other's error.
-      HasError = true;
-      new (getErrorStorage()) std::error_code(Other.getError());
-    }
-  }
-
-  template <class T1>
-  static bool compareThisIfSameType(const T1 &a, const T1 &b) {
-    return &a == &b;
-  }
-
-  template <class T1, class T2>
-  static bool compareThisIfSameType(const T1 &a, const T2 &b) {
-    return false;
-  }
-
-  template <class OtherT>
-  void copyAssign(const ErrorOr<OtherT> &Other) {
-    if (compareThisIfSameType(*this, Other))
-      return;
-
-    this->~ErrorOr();
-    new (this) ErrorOr(Other);
-  }
-
-  template <class OtherT>
-  void moveConstruct(ErrorOr<OtherT> &&Other) {
-    if (!Other.HasError) {
-      // Get the other value.
-      HasError = false;
-      new (getStorage()) storage_type(std::move(*Other.getStorage()));
-    } else {
-      // Get other's error.
-      HasError = true;
-      new (getErrorStorage()) std::error_code(Other.getError());
-    }
-  }
-
-  template <class OtherT>
-  void moveAssign(ErrorOr<OtherT> &&Other) {
-    if (compareThisIfSameType(*this, Other))
-      return;
-
-    this->~ErrorOr();
-    new (this) ErrorOr(std::move(Other));
-  }
-
-  pointer toPointer(pointer Val) {
-    return Val;
-  }
-
-  const_pointer toPointer(const_pointer Val) const { return Val; }
-
-  pointer toPointer(wrap *Val) {
-    return &Val->get();
-  }
-
-  const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
-
-  storage_type *getStorage() {
-    assert(!HasError && "Cannot get value when an error exists!");
-    return reinterpret_cast<storage_type*>(TStorage.buffer);
-  }
-
-  const storage_type *getStorage() const {
-    assert(!HasError && "Cannot get value when an error exists!");
-    return reinterpret_cast<const storage_type*>(TStorage.buffer);
-  }
-
-  std::error_code *getErrorStorage() {
-    assert(HasError && "Cannot get error when a value exists!");
-    return reinterpret_cast<std::error_code *>(ErrorStorage.buffer);
-  }
-
-  const std::error_code *getErrorStorage() const {
-    return const_cast<ErrorOr<T> *>(this)->getErrorStorage();
-  }
-
-  union {
-    AlignedCharArrayUnion<storage_type> TStorage;
-    AlignedCharArrayUnion<std::error_code> ErrorStorage;
-  };
-  bool HasError : 1;
-};
-
-template <class T, class E>
-typename std::enable_if<std::is_error_code_enum<E>::value ||
-                            std::is_error_condition_enum<E>::value,
-                        bool>::type
-operator==(const ErrorOr<T> &Err, E Code) {
-  return Err.getError() == Code;
-}
-
-} // end namespace wpi
-
-#endif // LLVM_SUPPORT_ERROROR_H
diff --git a/wpiutil/src/main/native/include/wpi/Format.h b/wpiutil/src/main/native/include/wpi/Format.h
deleted file mode 100644
index ac4886a110..0000000000
--- a/wpiutil/src/main/native/include/wpi/Format.h
+++ /dev/null
@@ -1,265 +0,0 @@
-//===- Format.h - Efficient printf-style formatting for streams -*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the format() function, which can be used with other
-// LLVM subsystems to provide printf-style formatting.  This gives all the power
-// and risk of printf.  This can be used like this (with raw_ostreams as an
-// example):
-//
-//    OS << "mynumber: " << format("%4.5f", 1234.412) << '\n';
-//
-// Or if you prefer:
-//
-//  OS << format("mynumber: %4.5f\n", 1234.412);
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef WPIUTIL_WPI_FORMAT_H
-#define WPIUTIL_WPI_FORMAT_H
-
-#include "wpi/ArrayRef.h"
-#include "wpi/StringRef.h"
-#include <cassert>
-#include <cstdint>
-#include <cstdio>
-#include <optional>
-#include <tuple>
-#include <utility>
-
-namespace wpi {
-
-/// This is a helper class used for handling formatted output.  It is the
-/// abstract base class of a templated derived class.
-class format_object_base {
-protected:
-  const char *Fmt;
-  ~format_object_base() = default; // Disallow polymorphic deletion.
-  format_object_base(const format_object_base &) = default;
-  virtual void home(); // Out of line virtual method.
-
-  /// Call snprintf() for this object, on the given buffer and size.
-  virtual int snprint(char *Buffer, unsigned BufferSize) const = 0;
-
-public:
-  format_object_base(const char *fmt) : Fmt(fmt) {}
-
-  /// Format the object into the specified buffer.  On success, this returns
-  /// the length of the formatted string.  If the buffer is too small, this
-  /// returns a length to retry with, which will be larger than BufferSize.
-  unsigned print(char *Buffer, unsigned BufferSize) const {
-    assert(BufferSize && "Invalid buffer size!");
-
-    // Print the string, leaving room for the terminating null.
-    int N = snprint(Buffer, BufferSize);
-
-    // VC++ and old GlibC return negative on overflow, just double the size.
-    if (N < 0)
-      return BufferSize * 2;
-
-    // Other implementations yield number of bytes needed, not including the
-    // final '\0'.
-    if (unsigned(N) >= BufferSize)
-      return N + 1;
-
-    // Otherwise N is the length of output (not including the final '\0').
-    return N;
-  }
-};
-
-/// These are templated helper classes used by the format function that
-/// capture the object to be formatted and the format string. When actually
-/// printed, this synthesizes the string into a temporary buffer provided and
-/// returns whether or not it is big enough.
-
-// Helper to validate that format() parameters are scalars or pointers.
-template <typename... Args> struct validate_format_parameters;
-template <typename Arg, typename... Args>
-struct validate_format_parameters<Arg, Args...> {
-  static_assert(std::is_scalar<Arg>::value,
-                "format can't be used with non fundamental / non pointer type");
-  validate_format_parameters() { validate_format_parameters<Args...>(); }
-};
-template <> struct validate_format_parameters<> {};
-
-template <typename... Ts>
-class format_object final : public format_object_base {
-  std::tuple<Ts...> Vals;
-
-  template <std::size_t... Is>
-  int snprint_tuple(char *Buffer, unsigned BufferSize,
-                    std::index_sequence<Is...>) const {
-#ifdef _MSC_VER
-    return _snprintf(Buffer, BufferSize, Fmt, std::get<Is>(Vals)...);
-#else
-#ifdef __GNUC__
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wformat-nonliteral"
-#endif
-    return snprintf(Buffer, BufferSize, Fmt, std::get<Is>(Vals)...);
-#ifdef __GNUC__
-#pragma GCC diagnostic pop
-#endif
-#endif
-  }
-
-public:
-  format_object(const char *fmt, const Ts &... vals)
-      : format_object_base(fmt), Vals(vals...) {
-    validate_format_parameters<Ts...>();
-  }
-
-  int snprint(char *Buffer, unsigned BufferSize) const override {
-    return snprint_tuple(Buffer, BufferSize, std::index_sequence_for<Ts...>());
-  }
-};
-
-/// These are helper functions used to produce formatted output.  They use
-/// template type deduction to construct the appropriate instance of the
-/// format_object class to simplify their construction.
-///
-/// This is typically used like:
-/// \code
-///   OS << format("%0.4f", myfloat) << '\n';
-/// \endcode
-
-template <typename... Ts>
-inline format_object<Ts...> format(const char *Fmt, const Ts &... Vals) {
-  return format_object<Ts...>(Fmt, Vals...);
-}
-
-/// This is a helper class for left_justify, right_justify, and center_justify.
-class FormattedString {
-public:
-  enum Justification { JustifyNone, JustifyLeft, JustifyRight, JustifyCenter };
-  FormattedString(StringRef S, unsigned W, Justification J)
-      : Str(S), Width(W), Justify(J) {}
-
-private:
-  StringRef Str;
-  unsigned Width;
-  Justification Justify;
-  friend class raw_ostream;
-};
-
-/// left_justify - append spaces after string so total output is
-/// \p Width characters.  If \p Str is larger that \p Width, full string
-/// is written with no padding.
-inline FormattedString left_justify(StringRef Str, unsigned Width) {
-  return FormattedString(Str, Width, FormattedString::JustifyLeft);
-}
-
-/// right_justify - add spaces before string so total output is
-/// \p Width characters.  If \p Str is larger that \p Width, full string
-/// is written with no padding.
-inline FormattedString right_justify(StringRef Str, unsigned Width) {
-  return FormattedString(Str, Width, FormattedString::JustifyRight);
-}
-
-/// center_justify - add spaces before and after string so total output is
-/// \p Width characters.  If \p Str is larger that \p Width, full string
-/// is written with no padding.
-inline FormattedString center_justify(StringRef Str, unsigned Width) {
-  return FormattedString(Str, Width, FormattedString::JustifyCenter);
-}
-
-/// This is a helper class used for format_hex() and format_decimal().
-class FormattedNumber {
-  uint64_t HexValue;
-  int64_t DecValue;
-  unsigned Width;
-  bool Hex;
-  bool Upper;
-  bool HexPrefix;
-  friend class raw_ostream;
-
-public:
-  FormattedNumber(uint64_t HV, int64_t DV, unsigned W, bool H, bool U,
-                  bool Prefix)
-      : HexValue(HV), DecValue(DV), Width(W), Hex(H), Upper(U),
-        HexPrefix(Prefix) {}
-};
-
-/// format_hex - Output \p N as a fixed width hexadecimal. If number will not
-/// fit in width, full number is still printed.  Examples:
-///   OS << format_hex(255, 4)              => 0xff
-///   OS << format_hex(255, 4, true)        => 0xFF
-///   OS << format_hex(255, 6)              => 0x00ff
-///   OS << format_hex(255, 2)              => 0xff
-inline FormattedNumber format_hex(uint64_t N, unsigned Width,
-                                  bool Upper = false) {
-  assert(Width <= 18 && "hex width must be <= 18");
-  return FormattedNumber(N, 0, Width, true, Upper, true);
-}
-
-/// format_hex_no_prefix - Output \p N as a fixed width hexadecimal. Does not
-/// prepend '0x' to the outputted string.  If number will not fit in width,
-/// full number is still printed.  Examples:
-///   OS << format_hex_no_prefix(255, 2)              => ff
-///   OS << format_hex_no_prefix(255, 2, true)        => FF
-///   OS << format_hex_no_prefix(255, 4)              => 00ff
-///   OS << format_hex_no_prefix(255, 1)              => ff
-inline FormattedNumber format_hex_no_prefix(uint64_t N, unsigned Width,
-                                            bool Upper = false) {
-  assert(Width <= 16 && "hex width must be <= 16");
-  return FormattedNumber(N, 0, Width, true, Upper, false);
-}
-
-/// format_decimal - Output \p N as a right justified, fixed-width decimal. If
-/// number will not fit in width, full number is still printed.  Examples:
-///   OS << format_decimal(0, 5)     => "    0"
-///   OS << format_decimal(255, 5)   => "  255"
-///   OS << format_decimal(-1, 3)    => " -1"
-///   OS << format_decimal(12345, 3) => "12345"
-inline FormattedNumber format_decimal(int64_t N, unsigned Width) {
-  return FormattedNumber(0, N, Width, false, false, false);
-}
-
-class FormattedBytes {
-  ArrayRef<uint8_t> Bytes;
-
-  // If not nullopt, display offsets for each line relative to starting value.
-  std::optional<uint64_t> FirstByteOffset;
-  uint32_t IndentLevel;  // Number of characters to indent each line.
-  uint32_t NumPerLine;   // Number of bytes to show per line.
-  uint8_t ByteGroupSize; // How many hex bytes are grouped without spaces
-  bool Upper;            // Show offset and hex bytes as upper case.
-  bool ASCII;            // Show the ASCII bytes for the hex bytes to the right.
-  friend class raw_ostream;
-
-public:
-  FormattedBytes(ArrayRef<uint8_t> B, uint32_t IL, std::optional<uint64_t> O,
-                 uint32_t NPL, uint8_t BGS, bool U, bool A)
-      : Bytes(B), FirstByteOffset(O), IndentLevel(IL), NumPerLine(NPL),
-        ByteGroupSize(BGS), Upper(U), ASCII(A) {
-
-    if (ByteGroupSize > NumPerLine)
-      ByteGroupSize = NumPerLine;
-  }
-};
-
-inline FormattedBytes
-format_bytes(ArrayRef<uint8_t> Bytes, std::optional<uint64_t> FirstByteOffset = std::nullopt,
-             uint32_t NumPerLine = 16, uint8_t ByteGroupSize = 4,
-             uint32_t IndentLevel = 0, bool Upper = false) {
-  return FormattedBytes(Bytes, IndentLevel, FirstByteOffset, NumPerLine,
-                        ByteGroupSize, Upper, false);
-}
-
-inline FormattedBytes
-format_bytes_with_ascii(ArrayRef<uint8_t> Bytes,
-                        std::optional<uint64_t> FirstByteOffset = std::nullopt,
-                        uint32_t NumPerLine = 16, uint8_t ByteGroupSize = 4,
-                        uint32_t IndentLevel = 0, bool Upper = false) {
-  return FormattedBytes(Bytes, IndentLevel, FirstByteOffset, NumPerLine,
-                        ByteGroupSize, Upper, true);
-}
-
-} // end namespace wpi
-
-#endif
diff --git a/wpiutil/src/main/native/include/wpi/Hashing.h b/wpiutil/src/main/native/include/wpi/Hashing.h
index d59d695f65..e58bfdd192 100644
--- a/wpiutil/src/main/native/include/wpi/Hashing.h
+++ b/wpiutil/src/main/native/include/wpi/Hashing.h
@@ -53,6 +53,7 @@
 #include <cassert>
 #include <cstring>
 #include <string>
+#include <string_view>
 #include <utility>
 
 #ifdef _WIN32
@@ -660,6 +661,11 @@ hash_code hash_value(const std::basic_string<T> &arg) {
   return hash_combine_range(arg.begin(), arg.end());
 }
 
+template <typename T>
+hash_code hash_value(const std::basic_string_view<T> &arg) {
+  return hash_combine_range(arg.begin(), arg.end());
+}
+
 } // namespace wpi
 
 #ifdef _WIN32
diff --git a/wpiutil/src/main/native/include/wpi/HttpParser.h b/wpiutil/src/main/native/include/wpi/HttpParser.h
index 96d03db21b..72e5dad7b6 100644
--- a/wpiutil/src/main/native/include/wpi/HttpParser.h
+++ b/wpiutil/src/main/native/include/wpi/HttpParser.h
@@ -7,9 +7,10 @@
 
 #include <stdint.h>
 
+#include <string_view>
+
 #include "wpi/Signal.h"
 #include "wpi/SmallString.h"
-#include "wpi/StringRef.h"
 #include "wpi/http_parser.h"
 
 namespace wpi {
@@ -58,9 +59,10 @@ class HttpParser {
    * @param in input data
    * @return Trailing input data after the parse.
    */
-  StringRef Execute(StringRef in) {
-    return in.drop_front(
+  std::string_view Execute(std::string_view in) {
+    in.remove_prefix(
         http_parser_execute(&m_parser, &m_settings, in.data(), in.size()));
+    return in;
   }
 
   /**
@@ -136,7 +138,7 @@ class HttpParser {
   /**
    * Get URL.  Valid in and after the url callback has been called.
    */
-  StringRef GetUrl() const { return m_urlBuf; }
+  std::string_view GetUrl() const { return m_urlBuf.str(); }
 
   /**
    * Message begin callback.
@@ -148,7 +150,7 @@ class HttpParser {
    *
    * The parameter to the callback is the complete URL string.
    */
-  sig::Signal<StringRef> url;
+  sig::Signal<std::string_view> url;
 
   /**
    * Status callback.
@@ -156,14 +158,14 @@ class HttpParser {
    * The parameter to the callback is the complete status string.
    * GetStatusCode() can be used to get the numeric status code.
    */
-  sig::Signal<StringRef> status;
+  sig::Signal<std::string_view> status;
 
   /**
    * Header field callback.
    *
    * The parameters to the callback are the field name and field value.
    */
-  sig::Signal<StringRef, StringRef> header;
+  sig::Signal<std::string_view, std::string_view> header;
 
   /**
    * Headers complete callback.
@@ -183,7 +185,7 @@ class HttpParser {
    * multiple times arbitrarily (e.g. it's possible that it may be called with
    * just a few characters at a time).
    */
-  sig::Signal<StringRef, bool> body;
+  sig::Signal<std::string_view, bool> body;
 
   /**
    * Headers complete callback.
diff --git a/wpiutil/src/main/native/include/wpi/HttpServerConnection.h b/wpiutil/src/main/native/include/wpi/HttpServerConnection.h
index d2f815d6a3..b882dead51 100644
--- a/wpiutil/src/main/native/include/wpi/HttpServerConnection.h
+++ b/wpiutil/src/main/native/include/wpi/HttpServerConnection.h
@@ -6,11 +6,10 @@
 #define WPIUTIL_WPI_HTTPSERVERCONNECTION_H_
 
 #include <memory>
+#include <string_view>
 
 #include "wpi/ArrayRef.h"
 #include "wpi/HttpParser.h"
-#include "wpi/StringRef.h"
-#include "wpi/Twine.h"
 #include "wpi/uv/Stream.h"
 
 namespace wpi {
@@ -64,9 +63,9 @@ class HttpServerConnection {
    *                      be set to false.
    * @param extra Extra HTTP headers to send, including final "\r\n"
    */
-  virtual void BuildHeader(raw_ostream& os, int code, const Twine& codeText,
-                           const Twine& contentType, uint64_t contentLength,
-                           const Twine& extra = Twine{});
+  virtual void BuildHeader(raw_ostream& os, int code, std::string_view codeText,
+                           std::string_view contentType, uint64_t contentLength,
+                           std::string_view extra = {});
 
   /**
    * Send data to client.
@@ -91,9 +90,10 @@ class HttpServerConnection {
    * @param content Response message content
    * @param extraHeader Extra HTTP headers to send, including final "\r\n"
    */
-  virtual void SendResponse(int code, const Twine& codeText,
-                            const Twine& contentType, StringRef content,
-                            const Twine& extraHeader = Twine{});
+  virtual void SendResponse(int code, std::string_view codeText,
+                            std::string_view contentType,
+                            std::string_view content,
+                            std::string_view extraHeader = {});
 
   /**
    * Send HTTP response from static data, along with other header information
@@ -109,10 +109,10 @@ class HttpServerConnection {
    * @param gzipped True if content is gzip compressed
    * @param extraHeader Extra HTTP headers to send, including final "\r\n"
    */
-  virtual void SendStaticResponse(int code, const Twine& codeText,
-                                  const Twine& contentType, StringRef content,
-                                  bool gzipped,
-                                  const Twine& extraHeader = Twine{});
+  virtual void SendStaticResponse(int code, std::string_view codeText,
+                                  std::string_view contentType,
+                                  std::string_view content, bool gzipped,
+                                  std::string_view extraHeader = {});
 
   /**
    * Send error header and message.
@@ -123,7 +123,7 @@ class HttpServerConnection {
    * @param code HTTP error code (e.g. 404)
    * @param message Additional message text
    */
-  virtual void SendError(int code, const Twine& message = Twine{});
+  virtual void SendError(int code, std::string_view message = {});
 
   /** The HTTP request. */
   HttpParser m_request{HttpParser::kRequest};
diff --git a/wpiutil/src/main/native/include/wpi/HttpUtil.h b/wpiutil/src/main/native/include/wpi/HttpUtil.h
index 320ea4fae5..b0c97f88b7 100644
--- a/wpiutil/src/main/native/include/wpi/HttpUtil.h
+++ b/wpiutil/src/main/native/include/wpi/HttpUtil.h
@@ -9,6 +9,7 @@
 #include <memory>
 #include <optional>
 #include <string>
+#include <string_view>
 #include <utility>
 #include <vector>
 
@@ -17,8 +18,6 @@
 #include "wpi/SmallString.h"
 #include "wpi/SmallVector.h"
 #include "wpi/StringMap.h"
-#include "wpi/StringRef.h"
-#include "wpi/Twine.h"
 #include "wpi/raw_istream.h"
 #include "wpi/raw_socket_istream.h"
 #include "wpi/raw_socket_ostream.h"
@@ -29,15 +28,15 @@ namespace wpi {
 // @param buf Buffer for output
 // @param error Set to true if an error occurred
 // @return Escaped string
-StringRef UnescapeURI(const Twine& str, SmallVectorImpl<char>& buf,
-                      bool* error);
+std::string_view UnescapeURI(std::string_view str, SmallVectorImpl<char>& buf,
+                             bool* error);
 
 // Escape a string with %xx-encoding.
 // @param buf Buffer for output
 // @param spacePlus If true, encodes spaces to '+' rather than "%20"
 // @return Escaped string
-StringRef EscapeURI(const Twine& str, SmallVectorImpl<char>& buf,
-                    bool spacePlus = true);
+std::string_view EscapeURI(std::string_view str, SmallVectorImpl<char>& buf,
+                           bool spacePlus = true);
 
 // Parse a set of HTTP headers.  Saves just the Content-Type and Content-Length
 // fields.
@@ -55,7 +54,7 @@ bool ParseHttpHeaders(raw_istream& is, SmallVectorImpl<char>* contentType,
 // @param saveBuf If not null, all scanned characters up to but not including
 //     the boundary are saved to this string
 // @return False if error occurred on input stream, true if boundary found.
-bool FindMultipartBoundary(wpi::raw_istream& is, StringRef boundary,
+bool FindMultipartBoundary(wpi::raw_istream& is, std::string_view boundary,
                            std::string* saveBuf);
 
 /**
@@ -77,7 +76,7 @@ class HttpQueryMap {
    *
    * @param query query string
    */
-  explicit HttpQueryMap(StringRef query);
+  explicit HttpQueryMap(std::string_view query);
 
   /**
    * Gets an element of the query string.  Both the name and the returned
@@ -88,11 +87,11 @@ class HttpQueryMap {
    * @return Optional unescaped value.  Returns an empty optional if the
    *         name is not present in the query map.
    */
-  std::optional<StringRef> Get(StringRef name,
-                               SmallVectorImpl<char>& buf) const;
+  std::optional<std::string_view> Get(std::string_view name,
+                                      SmallVectorImpl<char>& buf) const;
 
  private:
-  StringMap<StringRef> m_elems;
+  StringMap<std::string_view> m_elems;
 };
 
 class HttpPathRef;
@@ -120,7 +119,7 @@ class HttpPath {
    * Constructs a HTTP path from an escaped path string.  Makes a copy of the
    * path, so it's safe to be a temporary.
    */
-  explicit HttpPath(StringRef path);
+  explicit HttpPath(std::string_view path);
 
   /**
    * Evaluates to true if the path is not empty.
@@ -143,11 +142,15 @@ class HttpPath {
    * @param match match list
    * @return True if path equals match list
    */
-  bool equals(std::initializer_list<StringRef> match) const {
+  bool equals(std::initializer_list<std::string_view> match) const {
     return equals(0, makeArrayRef(match.begin(), match.end()));
   }
-  bool equals(ArrayRef<StringRef> match) const { return equals(0, match); }
-  bool equals(StringRef match) const { return equals(0, makeArrayRef(match)); }
+  bool equals(ArrayRef<std::string_view> match) const {
+    return equals(0, match);
+  }
+  bool equals(std::string_view match) const {
+    return equals(0, makeArrayRef(match));
+  }
 
   /**
    * Returns true if the elements of the path starting at the "start" element
@@ -157,16 +160,17 @@ class HttpPath {
    * @param match match list
    * @return True if match
    */
-  bool equals(size_t start, std::initializer_list<StringRef> match) const {
+  bool equals(size_t start,
+              std::initializer_list<std::string_view> match) const {
     return equals(start, makeArrayRef(match.begin(), match.end()));
   }
-  bool equals(size_t start, ArrayRef<StringRef> match) const {
+  bool equals(size_t start, ArrayRef<std::string_view> match) const {
     if (m_pathEnds.size() != (start + match.size())) {
       return false;
     }
     return startswith(start, match);
   }
-  bool equals(size_t start, StringRef match) const {
+  bool equals(size_t start, std::string_view match) const {
     return equals(start, makeArrayRef(match));
   }
 
@@ -177,13 +181,13 @@ class HttpPath {
    * @param match match list
    * @return True if path starts with match list
    */
-  bool startswith(std::initializer_list<StringRef> match) const {
+  bool startswith(std::initializer_list<std::string_view> match) const {
     return startswith(0, makeArrayRef(match.begin(), match.end()));
   }
-  bool startswith(ArrayRef<StringRef> match) const {
+  bool startswith(ArrayRef<std::string_view> match) const {
     return startswith(0, match);
   }
-  bool startswith(StringRef match) const {
+  bool startswith(std::string_view match) const {
     return startswith(0, makeArrayRef(match));
   }
 
@@ -195,22 +199,21 @@ class HttpPath {
    * @param match match list
    * @return True if path starting at the start element matches the match list
    */
-  bool startswith(size_t start, std::initializer_list<StringRef> match) const {
+  bool startswith(size_t start,
+                  std::initializer_list<std::string_view> match) const {
     return startswith(start, makeArrayRef(match.begin(), match.end()));
   }
 
-  bool startswith(size_t start, ArrayRef<StringRef> match) const;
+  bool startswith(size_t start, ArrayRef<std::string_view> match) const;
 
-  bool startswith(size_t start, StringRef match) const {
+  bool startswith(size_t start, std::string_view match) const {
     return startswith(start, makeArrayRef(match));
   }
 
   /**
    * Gets a single element of the path.
    */
-  StringRef operator[](size_t n) const {
-    return m_pathBuf.slice(n == 0 ? 0 : m_pathEnds[n - 1], m_pathEnds[n]);
-  }
+  std::string_view operator[](size_t n) const;
 
   /**
    * Returns a path reference with the first N elements of the path removed.
@@ -236,44 +239,50 @@ class HttpPathRef {
   bool empty() const { return m_path && m_path->size() == m_start; }
   size_t size() const { return m_path ? m_path->size() - m_start : 0; }
 
-  bool equals(std::initializer_list<StringRef> match) const {
+  bool equals(std::initializer_list<std::string_view> match) const {
     return equals(0, makeArrayRef(match.begin(), match.end()));
   }
-  bool equals(ArrayRef<StringRef> match) const { return equals(0, match); }
-  bool equals(StringRef match) const { return equals(0, makeArrayRef(match)); }
+  bool equals(ArrayRef<std::string_view> match) const {
+    return equals(0, match);
+  }
+  bool equals(std::string_view match) const {
+    return equals(0, makeArrayRef(match));
+  }
 
-  bool equals(size_t start, std::initializer_list<StringRef> match) const {
+  bool equals(size_t start,
+              std::initializer_list<std::string_view> match) const {
     return equals(start, makeArrayRef(match.begin(), match.end()));
   }
-  bool equals(size_t start, ArrayRef<StringRef> match) const {
+  bool equals(size_t start, ArrayRef<std::string_view> match) const {
     return m_path ? m_path->equals(m_start + start, match) : false;
   }
-  bool equals(size_t start, StringRef match) const {
+  bool equals(size_t start, std::string_view match) const {
     return equals(start, makeArrayRef(match));
   }
 
-  bool startswith(std::initializer_list<StringRef> match) const {
+  bool startswith(std::initializer_list<std::string_view> match) const {
     return startswith(0, makeArrayRef(match.begin(), match.end()));
   }
-  bool startswith(ArrayRef<StringRef> match) const {
+  bool startswith(ArrayRef<std::string_view> match) const {
     return startswith(0, match);
   }
-  bool startswith(StringRef match) const {
+  bool startswith(std::string_view match) const {
     return startswith(0, makeArrayRef(match));
   }
 
-  bool startswith(size_t start, std::initializer_list<StringRef> match) const {
+  bool startswith(size_t start,
+                  std::initializer_list<std::string_view> match) const {
     return startswith(start, makeArrayRef(match.begin(), match.end()));
   }
-  bool startswith(size_t start, ArrayRef<StringRef> match) const {
+  bool startswith(size_t start, ArrayRef<std::string_view> match) const {
     return m_path ? m_path->startswith(m_start + start, match) : false;
   }
-  bool startswith(size_t start, StringRef match) const {
+  bool startswith(size_t start, std::string_view match) const {
     return startswith(start, makeArrayRef(match));
   }
 
-  StringRef operator[](size_t n) const {
-    return m_path ? m_path->operator[](m_start + n) : StringRef{};
+  std::string_view operator[](size_t n) const {
+    return m_path ? m_path->operator[](m_start + n) : std::string_view{};
   }
   HttpPathRef drop_front(size_t n) const {
     return m_path ? m_path->drop_front(m_start + n) : HttpPathRef{};
@@ -287,7 +296,7 @@ class HttpPathRef {
 class HttpLocation {
  public:
   HttpLocation() = default;
-  HttpLocation(const Twine& url_, bool* error, std::string* errorMsg);
+  HttpLocation(std::string_view url_, bool* error, std::string* errorMsg);
 
   std::string url;       // retain copy
   std::string user;      // unescaped
@@ -312,13 +321,13 @@ class HttpRequest {
   template <typename T>
   HttpRequest(const HttpLocation& loc, const T& extraParams);
 
-  HttpRequest(const HttpLocation& loc, StringRef path_)
+  HttpRequest(const HttpLocation& loc, std::string_view path_)
       : host{loc.host}, port{loc.port}, path{path_} {
     SetAuth(loc);
   }
 
   template <typename T>
-  HttpRequest(const HttpLocation& loc, StringRef path_, const T& params)
+  HttpRequest(const HttpLocation& loc, std::string_view path_, const T& params)
       : host{loc.host}, port{loc.port} {
     SetPath(path_, params);
     SetAuth(loc);
@@ -332,18 +341,18 @@ class HttpRequest {
  private:
   void SetAuth(const HttpLocation& loc);
   template <typename T>
-  void SetPath(StringRef path_, const T& params);
+  void SetPath(std::string_view path_, const T& params);
 
   template <typename T>
-  static StringRef GetFirst(const T& elem) {
+  static std::string_view GetFirst(const T& elem) {
     return elem.first;
   }
   template <typename T>
-  static StringRef GetFirst(const StringMapEntry<T>& elem) {
+  static std::string_view GetFirst(const StringMapEntry<T>& elem) {
     return elem.getKey();
   }
   template <typename T>
-  static StringRef GetSecond(const T& elem) {
+  static std::string_view GetSecond(const T& elem) {
     return elem.second;
   }
 };
@@ -368,14 +377,15 @@ class HttpConnection {
 
 class HttpMultipartScanner {
  public:
-  explicit HttpMultipartScanner(StringRef boundary, bool saveSkipped = false) {
+  explicit HttpMultipartScanner(std::string_view boundary,
+                                bool saveSkipped = false) {
     Reset(saveSkipped);
     SetBoundary(boundary);
   }
 
   // Change the boundary.  This is only safe to do when IsDone() is true (or
   // immediately after construction).
-  void SetBoundary(StringRef boundary);
+  void SetBoundary(std::string_view boundary);
 
   // Reset the scanner.  This allows reuse of internal buffers.
   void Reset(bool saveSkipped = false);
@@ -384,14 +394,14 @@ class HttpMultipartScanner {
   // is true.
   // @param in input data
   // @return the input not consumed; empty if all input consumed
-  StringRef Execute(StringRef in);
+  std::string_view Execute(std::string_view in);
 
   // Returns true when the boundary has been found.
   bool IsDone() const { return m_state == kDone; }
 
   // Get the skipped data.  Will be empty if saveSkipped was false.
-  StringRef GetSkipped() const {
-    return m_saveSkipped ? StringRef{m_buf} : StringRef{};
+  std::string_view GetSkipped() const {
+    return m_saveSkipped ? std::string_view{m_buf} : std::string_view{};
   }
 
  private:
diff --git a/wpiutil/src/main/native/include/wpi/HttpUtil.inc b/wpiutil/src/main/native/include/wpi/HttpUtil.inc
index a433402072..726cdfb158 100644
--- a/wpiutil/src/main/native/include/wpi/HttpUtil.inc
+++ b/wpiutil/src/main/native/include/wpi/HttpUtil.inc
@@ -18,7 +18,7 @@ inline HttpPathRef HttpPath::drop_front(size_t n) const {
 template <typename T>
 HttpRequest::HttpRequest(const HttpLocation& loc, const T& extraParams)
     : host{loc.host}, port{loc.port} {
-  StringMap<StringRef> params;
+  StringMap<std::string_view> params;
   for (const auto& p : loc.params) {
     params.insert(std::make_pair(GetFirst(p), GetSecond(p)));
   }
@@ -30,7 +30,7 @@ HttpRequest::HttpRequest(const HttpLocation& loc, const T& extraParams)
 }
 
 template <typename T>
-void HttpRequest::SetPath(StringRef path_, const T& params) {
+void HttpRequest::SetPath(std::string_view path_, const T& params) {
   // Build location including query string
   raw_svector_ostream pathOs{path};
   pathOs << path_;
diff --git a/wpiutil/src/main/native/include/wpi/HttpWebSocketServerConnection.h b/wpiutil/src/main/native/include/wpi/HttpWebSocketServerConnection.h
index f42f0fbc84..a59375d2e6 100644
--- a/wpiutil/src/main/native/include/wpi/HttpWebSocketServerConnection.h
+++ b/wpiutil/src/main/native/include/wpi/HttpWebSocketServerConnection.h
@@ -8,11 +8,11 @@
 #include <initializer_list>
 #include <memory>
 #include <string>
+#include <string_view>
 
 #include "wpi/ArrayRef.h"
 #include "wpi/HttpServerConnection.h"
 #include "wpi/SmallVector.h"
-#include "wpi/StringRef.h"
 #include "wpi/WebSocket.h"
 #include "wpi/WebSocketServer.h"
 #include "wpi/uv/Stream.h"
@@ -36,7 +36,7 @@ class HttpWebSocketServerConnection
    * @param protocols Acceptable subprotocols
    */
   HttpWebSocketServerConnection(std::shared_ptr<uv::Stream> stream,
-                                ArrayRef<StringRef> protocols);
+                                ArrayRef<std::string_view> protocols);
 
   /**
    * Constructor.
@@ -44,8 +44,9 @@ class HttpWebSocketServerConnection
    * @param stream network stream
    * @param protocols Acceptable subprotocols
    */
-  HttpWebSocketServerConnection(std::shared_ptr<uv::Stream> stream,
-                                std::initializer_list<StringRef> protocols)
+  HttpWebSocketServerConnection(
+      std::shared_ptr<uv::Stream> stream,
+      std::initializer_list<std::string_view> protocols)
       : HttpWebSocketServerConnection(
             stream, makeArrayRef(protocols.begin(), protocols.end())) {}
 
@@ -59,7 +60,7 @@ class HttpWebSocketServerConnection
    *
    * @param protocol negotiated subprotocol
    */
-  virtual bool IsValidWsUpgrade(StringRef protocol) { return true; }
+  virtual bool IsValidWsUpgrade(std::string_view protocol) { return true; }
 
   /**
    * Process an incoming WebSocket upgrade.  This is called after the header
diff --git a/wpiutil/src/main/native/include/wpi/HttpWebSocketServerConnection.inc b/wpiutil/src/main/native/include/wpi/HttpWebSocketServerConnection.inc
index 235f6ce729..3e084e9240 100644
--- a/wpiutil/src/main/native/include/wpi/HttpWebSocketServerConnection.inc
+++ b/wpiutil/src/main/native/include/wpi/HttpWebSocketServerConnection.inc
@@ -13,15 +13,16 @@ namespace wpi {
 
 template <typename Derived>
 HttpWebSocketServerConnection<Derived>::HttpWebSocketServerConnection(
-    std::shared_ptr<uv::Stream> stream, ArrayRef<StringRef> protocols)
+    std::shared_ptr<uv::Stream> stream, ArrayRef<std::string_view> protocols)
     : HttpServerConnection{stream},
       m_helper{m_request},
       m_protocols{protocols.begin(), protocols.end()} {
   // Handle upgrade event
   m_helper.upgrade.connect([this] {
     // Negotiate sub-protocol
-    SmallVector<StringRef, 2> protocols{m_protocols.begin(), m_protocols.end()};
-    StringRef protocol = m_helper.MatchProtocol(protocols).second;
+    SmallVector<std::string_view, 2> protocols{m_protocols.begin(),
+                                               m_protocols.end()};
+    std::string_view protocol = m_helper.MatchProtocol(protocols).second;
 
     // Check that the upgrade is valid
     if (!IsValidWsUpgrade(protocol)) {
diff --git a/wpiutil/src/main/native/include/wpi/Logger.h b/wpiutil/src/main/native/include/wpi/Logger.h
index 5ee14f506e..807e472c5b 100644
--- a/wpiutil/src/main/native/include/wpi/Logger.h
+++ b/wpiutil/src/main/native/include/wpi/Logger.h
@@ -8,8 +8,7 @@
 #include <functional>
 #include <utility>
 
-#include "wpi/SmallString.h"
-#include "wpi/raw_ostream.h"
+#include "fmt/format.h"
 
 namespace wpi {
 
@@ -40,12 +39,19 @@ class Logger {
   void set_min_level(unsigned int level) { m_min_level = level; }
   unsigned int min_level() const { return m_min_level; }
 
+  void DoLog(unsigned int level, const char* file, unsigned int line,
+             const char* msg);
+
+  void LogV(unsigned int level, const char* file, unsigned int line,
+            fmt::string_view format, fmt::format_args args);
+
+  template <typename S, typename... Args>
   void Log(unsigned int level, const char* file, unsigned int line,
-           const char* msg) {
-    if (!m_func || level < m_min_level) {
-      return;
+           const S& format, Args&&... args) {
+    if (m_func && level >= m_min_level) {
+      LogV(level, file, line, format,
+           fmt::make_args_checked<Args...>(format, args...));
     }
-    m_func(level, file, line, msg);
   }
 
   bool HasLogger() const { return m_func != nullptr; }
@@ -55,44 +61,43 @@ class Logger {
   unsigned int m_min_level = 20;
 };
 
-#define WPI_LOG(logger_inst, level, x)                                 \
-  do {                                                                 \
-    ::wpi::Logger& WPI_logger_ = logger_inst;                          \
-    if (WPI_logger_.min_level() <= static_cast<unsigned int>(level) && \
-        WPI_logger_.HasLogger()) {                                     \
-      ::wpi::SmallString<128> log_buf_;                                \
-      ::wpi::raw_svector_ostream log_os_{log_buf_};                    \
-      log_os_ << x;                                                    \
-      WPI_logger_.Log(level, __FILE__, __LINE__, log_buf_.c_str());    \
-    }                                                                  \
-  } while (0)
+#define WPI_LOG(logger_inst, level, format, ...) \
+  logger_inst.Log(level, __FILE__, __LINE__, FMT_STRING(format), __VA_ARGS__)
 
-#define WPI_ERROR(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_ERROR, x)
-#define WPI_WARNING(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_WARNING, x)
-#define WPI_INFO(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_INFO, x)
+#define WPI_ERROR(inst, format, ...) \
+  WPI_LOG(inst, ::wpi::WPI_LOG_ERROR, format, __VA_ARGS__)
+#define WPI_WARNING(inst, format, ...) \
+  WPI_LOG(inst, ::wpi::WPI_LOG_WARNING, format, __VA_ARGS__)
+#define WPI_INFO(inst, format, ...) \
+  WPI_LOG(inst, ::wpi::WPI_LOG_INFO, format, __VA_ARGS__)
 
 #ifdef NDEBUG
-#define WPI_DEBUG(inst, x) \
-  do {                     \
+#define WPI_DEBUG(inst, format, ...) \
+  do {                               \
   } while (0)
-#define WPI_DEBUG1(inst, x) \
-  do {                      \
+#define WPI_DEBUG1(inst, format, ...) \
+  do {                                \
   } while (0)
-#define WPI_DEBUG2(inst, x) \
-  do {                      \
+#define WPI_DEBUG2(inst, format, ...) \
+  do {                                \
   } while (0)
-#define WPI_DEBUG3(inst, x) \
-  do {                      \
+#define WPI_DEBUG3(inst, format, ...) \
+  do {                                \
   } while (0)
-#define WPI_DEBUG4(inst, x) \
-  do {                      \
+#define WPI_DEBUG4(inst, format, ...) \
+  do {                                \
   } while (0)
 #else
-#define WPI_DEBUG(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_DEBUG, x)
-#define WPI_DEBUG1(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_DEBUG1, x)
-#define WPI_DEBUG2(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_DEBUG2, x)
-#define WPI_DEBUG3(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_DEBUG3, x)
-#define WPI_DEBUG4(inst, x) WPI_LOG(inst, ::wpi::WPI_LOG_DEBUG4, x)
+#define WPI_DEBUG(inst, format, ...) \
+  WPI_LOG(inst, ::wpi::WPI_LOG_DEBUG, format, __VA_ARGS__)
+#define WPI_DEBUG1(inst, format, ...) \
+  WPI_LOG(inst, ::wpi::WPI_LOG_DEBUG1, format, __VA_ARGS__)
+#define WPI_DEBUG2(inst, format, ...) \
+  WPI_LOG(inst, ::wpi::WPI_LOG_DEBUG2, format, __VA_ARGS__)
+#define WPI_DEBUG3(inst, format, ...) \
+  WPI_LOG(inst, ::wpi::WPI_LOG_DEBUG3, format, __VA_ARGS__)
+#define WPI_DEBUG4(inst, format, ...) \
+  WPI_LOG(inst, ::wpi::WPI_LOG_DEBUG4, format, __VA_ARGS__)
 #endif
 
 }  // namespace wpi
diff --git a/wpiutil/src/main/native/include/wpi/MimeTypes.h b/wpiutil/src/main/native/include/wpi/MimeTypes.h
index 24796bf0e7..ce36ea26c2 100644
--- a/wpiutil/src/main/native/include/wpi/MimeTypes.h
+++ b/wpiutil/src/main/native/include/wpi/MimeTypes.h
@@ -5,11 +5,11 @@
 #ifndef WPIUTIL_WPI_MIMETYPES_H_
 #define WPIUTIL_WPI_MIMETYPES_H_
 
-#include "wpi/StringRef.h"
+#include <string_view>
 
 namespace wpi {
 
-StringRef MimeTypeFromPath(StringRef path);
+std::string_view MimeTypeFromPath(std::string_view path);
 
 }  // namespace wpi
 
diff --git a/wpiutil/src/main/native/include/wpi/NativeFormatting.h b/wpiutil/src/main/native/include/wpi/NativeFormatting.h
deleted file mode 100644
index 976adc8c99..0000000000
--- a/wpiutil/src/main/native/include/wpi/NativeFormatting.h
+++ /dev/null
@@ -1,49 +0,0 @@
-//===- NativeFormatting.h - Low level formatting helpers ---------*- C++-*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef WPIUTIL_WPI_NATIVE_FORMATTING_H
-#define WPIUTIL_WPI_NATIVE_FORMATTING_H
-
-#include "wpi/raw_ostream.h"
-
-#include <cstdint>
-#include <optional>
-
-namespace wpi {
-enum class FloatStyle { Exponent, ExponentUpper, Fixed, Percent };
-enum class IntegerStyle {
-  Integer,
-  Number,
-};
-enum class HexPrintStyle { Upper, Lower, PrefixUpper, PrefixLower };
-
-size_t getDefaultPrecision(FloatStyle Style);
-
-bool isPrefixedHexStyle(HexPrintStyle S);
-
-void write_integer(raw_ostream &S, unsigned int N, size_t MinDigits,
-                   IntegerStyle Style);
-void write_integer(raw_ostream &S, int N, size_t MinDigits, IntegerStyle Style);
-void write_integer(raw_ostream &S, unsigned long N, size_t MinDigits,
-                   IntegerStyle Style);
-void write_integer(raw_ostream &S, long N, size_t MinDigits,
-                   IntegerStyle Style);
-void write_integer(raw_ostream &S, unsigned long long N, size_t MinDigits,
-                   IntegerStyle Style);
-void write_integer(raw_ostream &S, long long N, size_t MinDigits,
-                   IntegerStyle Style);
-
-void write_hex(raw_ostream &S, uint64_t N, HexPrintStyle Style,
-               std::optional<size_t> Width = std::nullopt);
-void write_double(raw_ostream &S, double D, FloatStyle Style,
-                  std::optional<size_t> Precision = std::nullopt);
-}
-
-#endif
-
diff --git a/wpiutil/src/main/native/include/wpi/NetworkStream.h b/wpiutil/src/main/native/include/wpi/NetworkStream.h
index b40a3ddc37..b842ecdddb 100644
--- a/wpiutil/src/main/native/include/wpi/NetworkStream.h
+++ b/wpiutil/src/main/native/include/wpi/NetworkStream.h
@@ -6,8 +6,7 @@
 #define WPIUTIL_WPI_NETWORKSTREAM_H_
 
 #include <cstddef>
-
-#include "wpi/StringRef.h"
+#include <string_view>
 
 namespace wpi {
 
@@ -28,7 +27,7 @@ class NetworkStream {
                          int timeout = 0) = 0;
   virtual void close() = 0;
 
-  virtual StringRef getPeerIP() const = 0;
+  virtual std::string_view getPeerIP() const = 0;
   virtual int getPeerPort() const = 0;
   virtual void setNoDelay() = 0;
 
diff --git a/wpiutil/src/main/native/include/wpi/PortForwarder.h b/wpiutil/src/main/native/include/wpi/PortForwarder.h
index 63cd86cb3d..9e445a0368 100644
--- a/wpiutil/src/main/native/include/wpi/PortForwarder.h
+++ b/wpiutil/src/main/native/include/wpi/PortForwarder.h
@@ -8,8 +8,7 @@
 #pragma once
 
 #include <memory>
-
-#include "wpi/Twine.h"
+#include <string_view>
 
 namespace wpi {
 
@@ -38,7 +37,8 @@ class PortForwarder {
    * @param remoteHost remote IP address / DNS name
    * @param remotePort remote port number
    */
-  void Add(unsigned int port, const Twine& remoteHost, unsigned int remotePort);
+  void Add(unsigned int port, std::string_view remoteHost,
+           unsigned int remotePort);
 
   /**
    * Stop TCP forwarding on a port.
diff --git a/wpiutil/src/main/native/include/wpi/SmallString.h b/wpiutil/src/main/native/include/wpi/SmallString.h
index 32969b1669..1d44f24ea6 100644
--- a/wpiutil/src/main/native/include/wpi/SmallString.h
+++ b/wpiutil/src/main/native/include/wpi/SmallString.h
@@ -15,8 +15,8 @@
 #define WPIUTIL_WPI_SMALLSTRING_H
 
 #include "wpi/SmallVector.h"
-#include "wpi/StringRef.h"
 #include <cstddef>
+#include <string_view>
 
 namespace wpi {
 
@@ -28,8 +28,9 @@ public:
   /// Default ctor - Initialize to empty.
   SmallString() = default;
 
-  /// Initialize from a StringRef.
-  SmallString(StringRef S) : SmallVector<char, InternalLen>(S.begin(), S.end()) {}
+  /// Initialize from a std::string_view.
+  SmallString(std::string_view S)
+    : SmallVector<char, InternalLen>(S.begin(), S.end()) {}
 
   /// Initialize with a range.
   template<typename ItTy>
@@ -54,8 +55,8 @@ public:
     SmallVectorImpl<char>::append(S, E);
   }
 
-  /// Assign from a StringRef.
-  void assign(StringRef RHS) {
+  /// Assign from a std::string_view.
+  void assign(std::string_view RHS) {
     this->clear();
     SmallVectorImpl<char>::append(RHS.begin(), RHS.end());
   }
@@ -80,8 +81,8 @@ public:
     SmallVectorImpl<char>::append(NumInputs, Elt);
   }
 
-  /// Append from a StringRef.
-  void append(StringRef RHS) {
+  /// Append from a std::string_view.
+  void append(std::string_view RHS) {
     SmallVectorImpl<char>::append(RHS.begin(), RHS.end());
   }
 
@@ -94,48 +95,12 @@ public:
   /// @name String Comparison
   /// @{
 
-  /// Check for string equality.  This is more efficient than compare() when
-  /// the relative ordering of inequal strings isn't needed.
-  bool equals(StringRef RHS) const {
-    return str().equals(RHS);
-  }
-
-  /// Check for string equality, ignoring case.
-  bool equals_lower(StringRef RHS) const {
-    return str().equals_lower(RHS);
-  }
-
   /// Compare two strings; the result is -1, 0, or 1 if this string is
   /// lexicographically less than, equal to, or greater than the \p RHS.
-  int compare(StringRef RHS) const {
+  int compare(std::string_view RHS) const {
     return str().compare(RHS);
   }
 
-  /// compare_lower - Compare two strings, ignoring case.
-  int compare_lower(StringRef RHS) const {
-    return str().compare_lower(RHS);
-  }
-
-  /// compare_numeric - Compare two strings, treating sequences of digits as
-  /// numbers.
-  int compare_numeric(StringRef RHS) const {
-    return str().compare_numeric(RHS);
-  }
-
-  /// @}
-  /// @name String Predicates
-  /// @{
-
-  /// startswith - Check if this string starts with the given \p Prefix.
-  bool startswith(StringRef Prefix) const {
-    return str().startswith(Prefix);
-  }
-
-  /// endswith - Check if this string ends with the given \p Suffix.
-  bool endswith(StringRef Suffix) const {
-    return str().endswith(Suffix);
-  }
-
   /// @}
   /// @name String Searching
   /// @{
@@ -152,7 +117,7 @@ public:
   ///
   /// \returns The index of the first occurrence of \p Str, or npos if not
   /// found.
-  size_t find(StringRef Str, size_t From = 0) const {
+  size_t find(std::string_view Str, size_t From = 0) const {
     return str().find(Str, From);
   }
 
@@ -160,7 +125,7 @@ public:
   ///
   /// \returns The index of the last occurrence of \p C, or npos if not
   /// found.
-  size_t rfind(char C, size_t From = StringRef::npos) const {
+  size_t rfind(char C, size_t From = std::string_view::npos) const {
     return str().rfind(C, From);
   }
 
@@ -168,7 +133,7 @@ public:
   ///
   /// \returns The index of the last occurrence of \p Str, or npos if not
   /// found.
-  size_t rfind(StringRef Str) const {
+  size_t rfind(std::string_view Str) const {
     return str().rfind(Str);
   }
 
@@ -182,7 +147,7 @@ public:
   /// not found.
   ///
   /// Complexity: O(size() + Chars.size())
-  size_t find_first_of(StringRef Chars, size_t From = 0) const {
+  size_t find_first_of(std::string_view Chars, size_t From = 0) const {
     return str().find_first_of(Chars, From);
   }
 
@@ -196,13 +161,13 @@ public:
   /// \p Chars, or npos if not found.
   ///
   /// Complexity: O(size() + Chars.size())
-  size_t find_first_not_of(StringRef Chars, size_t From = 0) const {
+  size_t find_first_not_of(std::string_view Chars, size_t From = 0) const {
     return str().find_first_not_of(Chars, From);
   }
 
   /// Find the last character in the string that is \p C, or npos if not
   /// found.
-  size_t find_last_of(char C, size_t From = StringRef::npos) const {
+  size_t find_last_of(char C, size_t From = std::string_view::npos) const {
     return str().find_last_of(C, From);
   }
 
@@ -211,25 +176,10 @@ public:
   ///
   /// Complexity: O(size() + Chars.size())
   size_t find_last_of(
-      StringRef Chars, size_t From = StringRef::npos) const {
+      std::string_view Chars, size_t From = std::string_view::npos) const {
     return str().find_last_of(Chars, From);
   }
 
-  /// @}
-  /// @name Helpful Algorithms
-  /// @{
-
-  /// Return the number of occurrences of \p C in the string.
-  size_t count(char C) const {
-    return str().count(C);
-  }
-
-  /// Return the number of non-overlapped occurrences of \p Str in the
-  /// string.
-  size_t count(StringRef Str) const {
-    return str().count(Str);
-  }
-
   /// @}
   /// @name Substring Operations
   /// @{
@@ -243,28 +193,17 @@ public:
   /// \param N The number of characters to included in the substring. If \p N
   /// exceeds the number of characters remaining in the string, the string
   /// suffix (starting with \p Start) will be returned.
-  StringRef substr(size_t Start, size_t N = StringRef::npos) const {
+  std::string_view substr(size_t Start, size_t N = std::string_view::npos) const {
     return str().substr(Start, N);
   }
 
-  /// Return a reference to the substring from [Start, End).
-  ///
-  /// \param Start The index of the starting character in the substring; if
-  /// the index is npos or greater than the length of the string then the
-  /// empty substring will be returned.
-  ///
-  /// \param End The index following the last character to include in the
-  /// substring. If this is npos, or less than \p Start, or exceeds the
-  /// number of characters remaining in the string, the string suffix
-  /// (starting with \p Start) will be returned.
-  StringRef slice(size_t Start, size_t End) const {
-    return str().slice(Start, End);
-  }
-
   // Extra methods.
 
-  /// Explicit conversion to StringRef.
-  StringRef str() const { return StringRef(this->begin(), this->size()); }
+  /// Explicit conversion to std::string_view.
+  std::string_view str() const { return {this->begin(), this->size()}; }
+
+  /// Explicit conversion to std::string.
+  std::string string() const { return {this->begin(), this->size()}; }
 
   // TODO: Make this const, if it's safe...
   const char* c_str() {
@@ -273,16 +212,19 @@ public:
     return this->data();
   }
 
-  /// Implicit conversion to StringRef.
-  operator StringRef() const { return str(); }
+  /// Implicit conversion to std::string_view.
+  operator std::string_view() const { return str(); }
+
+  /// Implicit conversion to std::string.
+  operator std::string() const { return string(); }
 
   // Extra operators.
-  const SmallString &operator=(StringRef RHS) {
+  const SmallString &operator=(std::string_view RHS) {
     this->clear();
     return *this += RHS;
   }
 
-  SmallString &operator+=(StringRef RHS) {
+  SmallString &operator+=(std::string_view RHS) {
     this->append(RHS.begin(), RHS.end());
     return *this;
   }
diff --git a/wpiutil/src/main/native/include/wpi/StringMap.h b/wpiutil/src/main/native/include/wpi/StringMap.h
index dbfe8ede15..3f31931b77 100644
--- a/wpiutil/src/main/native/include/wpi/StringMap.h
+++ b/wpiutil/src/main/native/include/wpi/StringMap.h
@@ -15,7 +15,6 @@
 #define WPIUTIL_WPI_STRINGMAP_H
 
 #include "wpi/SmallVector.h"
-#include "wpi/StringRef.h"
 #include "wpi/iterator.h"
 #include "wpi/iterator_range.h"
 #include "wpi/MemAlloc.h"
@@ -29,6 +28,7 @@
 #include <cstring>
 #include <initializer_list>
 #include <iterator>
+#include <string_view>
 #include <utility>
 
 namespace wpi {
@@ -82,12 +82,12 @@ protected:
   /// specified bucket will be non-null.  Otherwise, it will be null.  In either
   /// case, the FullHashValue field of the bucket will be set to the hash value
   /// of the string.
-  unsigned LookupBucketFor(StringRef Key);
+  unsigned LookupBucketFor(std::string_view Key);
 
   /// FindKey - Look up the bucket that contains the specified key. If it exists
   /// in the map, return the bucket number of the key.  Otherwise return -1.
   /// This does not modify the map.
-  int FindKey(StringRef Key) const;
+  int FindKey(std::string_view Key) const;
 
   /// RemoveKey - Remove the specified StringMapEntry from the table, but do not
   /// delete it.  This aborts if the value isn't in the table.
@@ -95,7 +95,7 @@ protected:
 
   /// RemoveKey - Remove the StringMapEntry for the specified key from the
   /// table, returning it.  If the key is not in the table, this returns null.
-  StringMapEntryBase *RemoveKey(StringRef Key);
+  StringMapEntryBase *RemoveKey(std::string_view Key);
 
   /// Allocate the table with the specified number of buckets and otherwise
   /// setup the map as empty.
@@ -137,8 +137,8 @@ public:
       : StringMapEntryBase(strLen), second(std::forward<InitTy>(InitVals)...) {}
   StringMapEntry(StringMapEntry &E) = delete;
 
-  StringRef getKey() const {
-    return StringRef(getKeyData(), getKeyLength());
+  std::string_view getKey() const {
+    return {getKeyData(), getKeyLength()};
   }
 
   const ValueTy &getValue() const { return second; }
@@ -151,12 +151,12 @@ public:
   /// StringMapEntry object.
   const char *getKeyData() const {return reinterpret_cast<const char*>(this+1);}
 
-  StringRef first() const { return StringRef(getKeyData(), getKeyLength()); }
+  std::string_view first() const { return {getKeyData(), getKeyLength()}; }
 
   /// Create a StringMapEntry for the specified key construct the value using
   /// \p InitiVals.
   template <typename... InitTy>
-  static StringMapEntry *Create(StringRef Key, InitTy &&... InitVals) {
+  static StringMapEntry *Create(std::string_view Key, InitTy &&... InitVals) {
     size_t KeyLength = Key.size();
 
     // Allocate a new item with space for the string at the end and a null
@@ -177,7 +177,7 @@ public:
     return NewItem;
   }
 
-  static StringMapEntry *Create(StringRef Key) {
+  static StringMapEntry *Create(std::string_view Key) {
     return Create(Key, ValueTy());
   }
 
@@ -212,7 +212,7 @@ public:
   explicit StringMap(unsigned InitialSize)
     : StringMapImpl(InitialSize, static_cast<unsigned>(sizeof(MapEntryTy))) {}
 
-  StringMap(std::initializer_list<std::pair<StringRef, ValueTy>> List)
+  StringMap(std::initializer_list<std::pair<std::string_view, ValueTy>> List)
       : StringMapImpl(List.size(), static_cast<unsigned>(sizeof(MapEntryTy))) {
     for (const auto &P : List) {
       insert(P);
@@ -302,13 +302,13 @@ public:
                       StringMapKeyIterator<ValueTy>(end()));
   }
 
-  iterator find(StringRef Key) {
+  iterator find(std::string_view Key) {
     int Bucket = FindKey(Key);
     if (Bucket == -1) return end();
     return iterator(TheTable+Bucket, true);
   }
 
-  const_iterator find(StringRef Key) const {
+  const_iterator find(std::string_view Key) const {
     int Bucket = FindKey(Key);
     if (Bucket == -1) return end();
     return const_iterator(TheTable+Bucket, true);
@@ -316,7 +316,7 @@ public:
 
   /// lookup - Return the entry for the specified key, or a default
   /// constructed value if no such entry exists.
-  ValueTy lookup(StringRef Key) const {
+  ValueTy lookup(std::string_view Key) const {
     const_iterator it = find(Key);
     if (it != end())
       return it->second;
@@ -325,10 +325,10 @@ public:
 
   /// Lookup the ValueTy for the \p Key, or create a default constructed value
   /// if the key is not in the map.
-  ValueTy &operator[](StringRef Key) { return try_emplace(Key).first->second; }
+  ValueTy &operator[](std::string_view Key) { return try_emplace(Key).first->second; }
 
   /// count - Return 1 if the element is in the map, 0 otherwise.
-  size_type count(StringRef Key) const {
+  size_type count(std::string_view Key) const {
     return find(Key) == end() ? 0 : 1;
   }
 
@@ -355,7 +355,7 @@ public:
   /// isn't already in the map. The bool component of the returned pair is true
   /// if and only if the insertion takes place, and the iterator component of
   /// the pair points to the element with key equivalent to the key of the pair.
-  std::pair<iterator, bool> insert(std::pair<StringRef, ValueTy> KV) {
+  std::pair<iterator, bool> insert(std::pair<std::string_view, ValueTy> KV) {
     return try_emplace(KV.first, std::move(KV.second));
   }
 
@@ -364,7 +364,7 @@ public:
   /// if and only if the insertion takes place, and the iterator component of
   /// the pair points to the element with key equivalent to the key of the pair.
   template <typename... ArgsTy>
-  std::pair<iterator, bool> try_emplace(StringRef Key, ArgsTy &&... Args) {
+  std::pair<iterator, bool> try_emplace(std::string_view Key, ArgsTy &&... Args) {
     unsigned BucketNo = LookupBucketFor(Key);
     StringMapEntryBase *&Bucket = TheTable[BucketNo];
     if (Bucket && Bucket != getTombstoneVal())
@@ -411,7 +411,7 @@ public:
     V.Destroy();
   }
 
-  bool erase(StringRef Key) {
+  bool erase(std::string_view Key) {
     iterator I = find(Key);
     if (I == end()) return false;
     erase(I);
@@ -524,23 +524,23 @@ template <typename ValueTy>
 class StringMapKeyIterator
     : public iterator_adaptor_base<StringMapKeyIterator<ValueTy>,
                                    StringMapConstIterator<ValueTy>,
-                                   std::forward_iterator_tag, StringRef> {
+                                   std::forward_iterator_tag, std::string_view> {
   using base = iterator_adaptor_base<StringMapKeyIterator<ValueTy>,
                                      StringMapConstIterator<ValueTy>,
-                                     std::forward_iterator_tag, StringRef>;
+                                     std::forward_iterator_tag, std::string_view>;
 
 public:
   StringMapKeyIterator() = default;
   explicit StringMapKeyIterator(StringMapConstIterator<ValueTy> Iter)
       : base(std::move(Iter)) {}
 
-  StringRef &operator*() {
+  std::string_view &operator*() {
     Key = this->wrapped()->getKey();
     return Key;
   }
 
 private:
-  StringRef Key;
+  std::string_view Key;
 };
 
 template <typename ValueTy>
@@ -594,13 +594,13 @@ bool operator<(const StringMap<ValueTy>& lhs, const StringMap<ValueTy>& rhs) {
   if (&lhs == &rhs) return false;
 
   // copy into vectors and sort by key
-  SmallVector<StringRef, 16> lhs_keys;
+  SmallVector<std::string_view, 16> lhs_keys;
   lhs_keys.reserve(lhs.size());
   for (auto i = lhs.begin(), end = lhs.end(); i != end; ++i)
     lhs_keys.push_back(i->getKey());
   std::sort(lhs_keys.begin(), lhs_keys.end());
 
-  SmallVector<StringRef, 16> rhs_keys;
+  SmallVector<std::string_view, 16> rhs_keys;
   rhs_keys.reserve(rhs.size());
   for (auto i = rhs.begin(), end = rhs.end(); i != end; ++i)
     rhs_keys.push_back(i->getKey());
diff --git a/wpiutil/src/main/native/include/wpi/StringRef.h b/wpiutil/src/main/native/include/wpi/StringRef.h
deleted file mode 100644
index b804605f9d..0000000000
--- a/wpiutil/src/main/native/include/wpi/StringRef.h
+++ /dev/null
@@ -1,956 +0,0 @@
-//===- StringRef.h - Constant String Reference Wrapper ----------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef WPIUTIL_WPI_STRINGREF_H
-#define WPIUTIL_WPI_STRINGREF_H
-
-#include "wpi/STLExtras.h"
-#include "wpi/iterator_range.h"
-#include "wpi/Compiler.h"
-#include <algorithm>
-#include <cassert>
-#include <cstddef>
-#include <cstring>
-#include <iosfwd>
-#include <limits>
-#include <string>
-#include <string_view>
-#include <type_traits>
-#include <utility>
-
-namespace wpi {
-
-  class hash_code;
-  template <typename T> class SmallVectorImpl;
-  class StringRef;
-
-  /// Helper functions for StringRef::getAsInteger.
-  bool getAsUnsignedInteger(StringRef Str, unsigned Radix,
-                            unsigned long long &Result) noexcept;
-
-  bool getAsSignedInteger(StringRef Str, unsigned Radix, long long &Result) noexcept;
-
-  bool consumeUnsignedInteger(StringRef &Str, unsigned Radix,
-                              unsigned long long &Result) noexcept;
-  bool consumeSignedInteger(StringRef &Str, unsigned Radix, long long &Result) noexcept;
-
-  /// StringRef - Represent a constant reference to a string, i.e. a character
-  /// array and a length, which need not be null terminated.
-  ///
-  /// This class does not own the string data, it is expected to be used in
-  /// situations where the character data resides in some other buffer, whose
-  /// lifetime extends past that of the StringRef. For this reason, it is not in
-  /// general safe to store a StringRef.
-  class StringRef {
-  public:
-    static const size_t npos = ~size_t(0);
-
-    using iterator = const char *;
-    using const_iterator = const char *;
-    using size_type = size_t;
-
-  private:
-    /// The start of the string, in an external buffer.
-    const char *Data = nullptr;
-
-    /// The length of the string.
-    size_t Length = 0;
-
-    // Workaround memcmp issue with null pointers (undefined behavior)
-    // by providing a specialized version
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    static int compareMemory(const char *Lhs, const char *Rhs, size_t Length) noexcept {
-      if (Length == 0) { return 0; }
-      return ::memcmp(Lhs,Rhs,Length);
-    }
-
-  public:
-    /// @name Constructors
-    /// @{
-
-    /// Construct an empty string ref.
-    /*implicit*/ StringRef() = default;
-
-    /// Disable conversion from nullptr.  This prevents things like
-    /// if (S == nullptr)
-    StringRef(std::nullptr_t) = delete;
-
-    /// Construct a string ref from a cstring.
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    /*implicit*/ StringRef(const char *Str) noexcept
-        : Data(Str), Length(Str ? ::strlen(Str) : 0) {}
-
-    /// Construct a string ref from a pointer and length.
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    /*implicit*/ constexpr StringRef(const char *data, size_t length) noexcept
-        : Data(data), Length(length) {}
-
-    /// Construct a string ref from an std::string.
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    /*implicit*/ StringRef(const std::string &Str) noexcept
-      : Data(Str.data()), Length(Str.length()) {}
-
-    /// Construct a string ref from an std::string_view.
-    /*implicit*/ constexpr StringRef(std::string_view Str)
-        : Data(Str.data()), Length(Str.size()) {}
-
-    static StringRef withNullAsEmpty(const char *data) noexcept {
-      return StringRef(data ? data : "");
-    }
-
-    /// @}
-    /// @name Iterators
-    /// @{
-
-    iterator begin() const noexcept { return Data; }
-
-    iterator end() const noexcept { return Data + Length; }
-
-    const unsigned char *bytes_begin() const noexcept {
-      return reinterpret_cast<const unsigned char *>(begin());
-    }
-    const unsigned char *bytes_end() const noexcept {
-      return reinterpret_cast<const unsigned char *>(end());
-    }
-    iterator_range<const unsigned char *> bytes() const noexcept {
-      return make_range(bytes_begin(), bytes_end());
-    }
-
-    /// @}
-    /// @name String Operations
-    /// @{
-
-    /// data - Get a pointer to the start of the string (which may not be null
-    /// terminated).
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    const char *data() const noexcept { return Data; }
-
-    /// empty - Check if the string is empty.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    bool empty() const noexcept { return Length == 0; }
-
-    /// size - Get the string size.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    size_t size() const noexcept { return Length; }
-
-    /// front - Get the first character in the string.
-    LLVM_NODISCARD
-    char front() const noexcept {
-      assert(!empty());
-      return Data[0];
-    }
-
-    /// back - Get the last character in the string.
-    LLVM_NODISCARD
-    char back() const noexcept {
-      assert(!empty());
-      return Data[Length-1];
-    }
-
-    // copy - Allocate copy in Allocator and return StringRef to it.
-    template <typename Allocator>
-    LLVM_NODISCARD StringRef copy(Allocator &A) const {
-      // Don't request a length 0 copy from the allocator.
-      if (empty())
-        return StringRef();
-      char *S = A.template Allocate<char>(Length);
-      std::copy(begin(), end(), S);
-      return StringRef(S, Length);
-    }
-
-    /// equals - Check for string equality, this is more efficient than
-    /// compare() when the relative ordering of inequal strings isn't needed.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    bool equals(StringRef RHS) const noexcept {
-      return (Length == RHS.Length &&
-              compareMemory(Data, RHS.Data, RHS.Length) == 0);
-    }
-
-    /// equals_lower - Check for string equality, ignoring case.
-    LLVM_NODISCARD
-    bool equals_lower(StringRef RHS) const noexcept {
-      return Length == RHS.Length && compare_lower(RHS) == 0;
-    }
-
-    /// compare - Compare two strings; the result is -1, 0, or 1 if this string
-    /// is lexicographically less than, equal to, or greater than the \p RHS.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    int compare(StringRef RHS) const noexcept {
-      // Check the prefix for a mismatch.
-      if (int Res = compareMemory(Data, RHS.Data, (std::min)(Length, RHS.Length)))
-        return Res < 0 ? -1 : 1;
-
-      // Otherwise the prefixes match, so we only need to check the lengths.
-      if (Length == RHS.Length)
-        return 0;
-      return Length < RHS.Length ? -1 : 1;
-    }
-
-    /// compare_lower - Compare two strings, ignoring case.
-    LLVM_NODISCARD
-    int compare_lower(StringRef RHS) const noexcept;
-
-    /// compare_numeric - Compare two strings, treating sequences of digits as
-    /// numbers.
-    LLVM_NODISCARD
-    int compare_numeric(StringRef RHS) const noexcept;
-
-    /// str - Get the contents as an std::string.
-    LLVM_NODISCARD
-    std::string str() const {
-      if (!Data) return std::string();
-      return std::string(Data, Length);
-    }
-
-    /// @}
-    /// @name Operator Overloads
-    /// @{
-
-    LLVM_NODISCARD
-    char operator[](size_t Index) const noexcept {
-      assert(Index < Length && "Invalid index!");
-      return Data[Index];
-    }
-
-    /// Disallow accidental assignment from a temporary std::string.
-    ///
-    /// The declaration here is extra complicated so that `stringRef = {}`
-    /// and `stringRef = "abc"` continue to select the move assignment operator.
-    template <typename T>
-    typename std::enable_if<std::is_same<T, std::string>::value,
-                            StringRef>::type &
-    operator=(T &&Str) = delete;
-
-    /// @}
-    /// @name Type Conversions
-    /// @{
-
-    operator std::string() const {
-      return str();
-    }
-
-    operator std::string_view() const {
-      return std::string_view(data(), size());
-    }
-
-    /// @}
-    /// @name String Predicates
-    /// @{
-
-    /// Check if this string starts with the given \p Prefix.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    bool startswith(StringRef Prefix) const noexcept {
-      return Length >= Prefix.Length &&
-             compareMemory(Data, Prefix.Data, Prefix.Length) == 0;
-    }
-
-    /// Check if this string starts with the given \p Prefix, ignoring case.
-    LLVM_NODISCARD
-    bool startswith_lower(StringRef Prefix) const noexcept;
-
-    /// Check if this string ends with the given \p Suffix.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    bool endswith(StringRef Suffix) const noexcept {
-      return Length >= Suffix.Length &&
-        compareMemory(end() - Suffix.Length, Suffix.Data, Suffix.Length) == 0;
-    }
-
-    /// Check if this string ends with the given \p Suffix, ignoring case.
-    LLVM_NODISCARD
-    bool endswith_lower(StringRef Suffix) const noexcept;
-
-    /// @}
-    /// @name String Searching
-    /// @{
-
-    /// Search for the first character \p C in the string.
-    ///
-    /// \returns The index of the first occurrence of \p C, or npos if not
-    /// found.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    size_t find(char C, size_t From = 0) const noexcept {
-      size_t FindBegin = (std::min)(From, Length);
-      if (FindBegin < Length) { // Avoid calling memchr with nullptr.
-        // Just forward to memchr, which is faster than a hand-rolled loop.
-        if (const void *P = ::memchr(Data + FindBegin, C, Length - FindBegin))
-          return static_cast<const char *>(P) - Data;
-      }
-      return npos;
-    }
-
-    /// Search for the first character \p C in the string, ignoring case.
-    ///
-    /// \returns The index of the first occurrence of \p C, or npos if not
-    /// found.
-    LLVM_NODISCARD
-    size_t find_lower(char C, size_t From = 0) const noexcept;
-
-    /// Search for the first character satisfying the predicate \p F
-    ///
-    /// \returns The index of the first character satisfying \p F starting from
-    /// \p From, or npos if not found.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    size_t find_if(function_ref<bool(char)> F, size_t From = 0) const noexcept {
-      StringRef S = drop_front(From);
-      while (!S.empty()) {
-        if (F(S.front()))
-          return size() - S.size();
-        S = S.drop_front();
-      }
-      return npos;
-    }
-
-    /// Search for the first character not satisfying the predicate \p F
-    ///
-    /// \returns The index of the first character not satisfying \p F starting
-    /// from \p From, or npos if not found.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    size_t find_if_not(function_ref<bool(char)> F, size_t From = 0) const noexcept {
-      return find_if([F](char c) { return !F(c); }, From);
-    }
-
-    /// Search for the first string \p Str in the string.
-    ///
-    /// \returns The index of the first occurrence of \p Str, or npos if not
-    /// found.
-    LLVM_NODISCARD
-    size_t find(StringRef Str, size_t From = 0) const noexcept;
-
-    /// Search for the first string \p Str in the string, ignoring case.
-    ///
-    /// \returns The index of the first occurrence of \p Str, or npos if not
-    /// found.
-    LLVM_NODISCARD
-    size_t find_lower(StringRef Str, size_t From = 0) const noexcept;
-
-    /// Search for the last character \p C in the string.
-    ///
-    /// \returns The index of the last occurrence of \p C, or npos if not
-    /// found.
-    LLVM_NODISCARD
-    size_t rfind(char C, size_t From = npos) const noexcept {
-      From = (std::min)(From, Length);
-      size_t i = From;
-      while (i != 0) {
-        --i;
-        if (Data[i] == C)
-          return i;
-      }
-      return npos;
-    }
-
-    /// Search for the last character \p C in the string, ignoring case.
-    ///
-    /// \returns The index of the last occurrence of \p C, or npos if not
-    /// found.
-    LLVM_NODISCARD
-    size_t rfind_lower(char C, size_t From = npos) const noexcept;
-
-    /// Search for the last string \p Str in the string.
-    ///
-    /// \returns The index of the last occurrence of \p Str, or npos if not
-    /// found.
-    LLVM_NODISCARD
-    size_t rfind(StringRef Str) const noexcept;
-
-    /// Search for the last string \p Str in the string, ignoring case.
-    ///
-    /// \returns The index of the last occurrence of \p Str, or npos if not
-    /// found.
-    LLVM_NODISCARD
-    size_t rfind_lower(StringRef Str) const noexcept;
-
-    /// Find the first character in the string that is \p C, or npos if not
-    /// found. Same as find.
-    LLVM_NODISCARD
-    size_t find_first_of(char C, size_t From = 0) const noexcept {
-      return find(C, From);
-    }
-
-    /// Find the first character in the string that is in \p Chars, or npos if
-    /// not found.
-    ///
-    /// Complexity: O(size() + Chars.size())
-    LLVM_NODISCARD
-    size_t find_first_of(StringRef Chars, size_t From = 0) const noexcept;
-
-    /// Find the first character in the string that is not \p C or npos if not
-    /// found.
-    LLVM_NODISCARD
-    size_t find_first_not_of(char C, size_t From = 0) const noexcept;
-
-    /// Find the first character in the string that is not in the string
-    /// \p Chars, or npos if not found.
-    ///
-    /// Complexity: O(size() + Chars.size())
-    LLVM_NODISCARD
-    size_t find_first_not_of(StringRef Chars, size_t From = 0) const noexcept;
-
-    /// Find the last character in the string that is \p C, or npos if not
-    /// found.
-    LLVM_NODISCARD
-    size_t find_last_of(char C, size_t From = npos) const noexcept {
-      return rfind(C, From);
-    }
-
-    /// Find the last character in the string that is in \p C, or npos if not
-    /// found.
-    ///
-    /// Complexity: O(size() + Chars.size())
-    LLVM_NODISCARD
-    size_t find_last_of(StringRef Chars, size_t From = npos) const noexcept;
-
-    /// Find the last character in the string that is not \p C, or npos if not
-    /// found.
-    LLVM_NODISCARD
-    size_t find_last_not_of(char C, size_t From = npos) const noexcept;
-
-    /// Find the last character in the string that is not in \p Chars, or
-    /// npos if not found.
-    ///
-    /// Complexity: O(size() + Chars.size())
-    LLVM_NODISCARD
-    size_t find_last_not_of(StringRef Chars, size_t From = npos) const noexcept;
-
-    /// Return true if the given string is a substring of *this, and false
-    /// otherwise.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    bool contains(StringRef Other) const noexcept { return find(Other) != npos; }
-
-    /// Return true if the given character is contained in *this, and false
-    /// otherwise.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    bool contains(char C) const noexcept { return find_first_of(C) != npos; }
-
-    /// Return true if the given string is a substring of *this, and false
-    /// otherwise.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    bool contains_lower(StringRef Other) const noexcept {
-      return find_lower(Other) != npos;
-    }
-
-    /// Return true if the given character is contained in *this, and false
-    /// otherwise.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    bool contains_lower(char C) const noexcept { return find_lower(C) != npos; }
-
-    /// @}
-    /// @name Helpful Algorithms
-    /// @{
-
-    /// Return the number of occurrences of \p C in the string.
-    LLVM_NODISCARD
-    size_t count(char C) const noexcept {
-      size_t Count = 0;
-      for (size_t i = 0, e = Length; i != e; ++i)
-        if (Data[i] == C)
-          ++Count;
-      return Count;
-    }
-
-    /// Return the number of non-overlapped occurrences of \p Str in
-    /// the string.
-    size_t count(StringRef Str) const noexcept;
-
-    /// Parse the current string as an integer of the specified radix.  If
-    /// \p Radix is specified as zero, this does radix autosensing using
-    /// extended C rules: 0 is octal, 0x is hex, 0b is binary.
-    ///
-    /// If the string is invalid or if only a subset of the string is valid,
-    /// this returns true to signify the error.  The string is considered
-    /// erroneous if empty or if it overflows T.
-    template <typename T>
-    typename std::enable_if<std::numeric_limits<T>::is_signed, bool>::type
-    getAsInteger(unsigned Radix, T &Result) const noexcept {
-      long long LLVal;
-      if (getAsSignedInteger(*this, Radix, LLVal) ||
-            static_cast<T>(LLVal) != LLVal)
-        return true;
-      Result = LLVal;
-      return false;
-    }
-
-    template <typename T>
-    typename std::enable_if<!std::numeric_limits<T>::is_signed, bool>::type
-    getAsInteger(unsigned Radix, T &Result) const noexcept {
-      unsigned long long ULLVal;
-      // The additional cast to unsigned long long is required to avoid the
-      // Visual C++ warning C4805: '!=' : unsafe mix of type 'bool' and type
-      // 'unsigned __int64' when instantiating getAsInteger with T = bool.
-      if (getAsUnsignedInteger(*this, Radix, ULLVal) ||
-          static_cast<unsigned long long>(static_cast<T>(ULLVal)) != ULLVal)
-        return true;
-      Result = ULLVal;
-      return false;
-    }
-
-    /// Parse the current string as an integer of the specified radix.  If
-    /// \p Radix is specified as zero, this does radix autosensing using
-    /// extended C rules: 0 is octal, 0x is hex, 0b is binary.
-    ///
-    /// If the string does not begin with a number of the specified radix,
-    /// this returns true to signify the error. The string is considered
-    /// erroneous if empty or if it overflows T.
-    /// The portion of the string representing the discovered numeric value
-    /// is removed from the beginning of the string.
-    template <typename T>
-    typename std::enable_if<std::numeric_limits<T>::is_signed, bool>::type
-    consumeInteger(unsigned Radix, T &Result) noexcept {
-      long long LLVal;
-      if (consumeSignedInteger(*this, Radix, LLVal) ||
-          static_cast<long long>(static_cast<T>(LLVal)) != LLVal)
-        return true;
-      Result = LLVal;
-      return false;
-    }
-
-    template <typename T>
-    typename std::enable_if<!std::numeric_limits<T>::is_signed, bool>::type
-    consumeInteger(unsigned Radix, T &Result) noexcept {
-      unsigned long long ULLVal;
-      if (consumeUnsignedInteger(*this, Radix, ULLVal) ||
-          static_cast<unsigned long long>(static_cast<T>(ULLVal)) != ULLVal)
-        return true;
-      Result = ULLVal;
-      return false;
-    }
-
-    /// @}
-    /// @name String Operations
-    /// @{
-
-    // Convert the given ASCII string to lowercase.
-    LLVM_NODISCARD
-    std::string lower() const;
-
-    /// Convert the given ASCII string to uppercase.
-    LLVM_NODISCARD
-    std::string upper() const;
-
-    /// @}
-    /// @name Substring Operations
-    /// @{
-
-    /// Return a reference to the substring from [Start, Start + N).
-    ///
-    /// \param Start The index of the starting character in the substring; if
-    /// the index is npos or greater than the length of the string then the
-    /// empty substring will be returned.
-    ///
-    /// \param N The number of characters to included in the substring. If N
-    /// exceeds the number of characters remaining in the string, the string
-    /// suffix (starting with \p Start) will be returned.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    StringRef substr(size_t Start, size_t N = npos) const noexcept {
-      Start = (std::min)(Start, Length);
-      return StringRef(Data + Start, (std::min)(N, Length - Start));
-    }
-
-    /// Return a StringRef equal to 'this' but with only the first \p N
-    /// elements remaining.  If \p N is greater than the length of the
-    /// string, the entire string is returned.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    StringRef take_front(size_t N = 1) const noexcept {
-      if (N >= size())
-        return *this;
-      return drop_back(size() - N);
-    }
-
-    /// Return a StringRef equal to 'this' but with only the last \p N
-    /// elements remaining.  If \p N is greater than the length of the
-    /// string, the entire string is returned.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    StringRef take_back(size_t N = 1) const noexcept {
-      if (N >= size())
-        return *this;
-      return drop_front(size() - N);
-    }
-
-    /// Return the longest prefix of 'this' such that every character
-    /// in the prefix satisfies the given predicate.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    StringRef take_while(function_ref<bool(char)> F) const noexcept {
-      return substr(0, find_if_not(F));
-    }
-
-    /// Return the longest prefix of 'this' such that no character in
-    /// the prefix satisfies the given predicate.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    StringRef take_until(function_ref<bool(char)> F) const noexcept {
-      return substr(0, find_if(F));
-    }
-
-    /// Return a StringRef equal to 'this' but with the first \p N elements
-    /// dropped.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    StringRef drop_front(size_t N = 1) const noexcept {
-      assert(size() >= N && "Dropping more elements than exist");
-      return substr(N);
-    }
-
-    /// Return a StringRef equal to 'this' but with the last \p N elements
-    /// dropped.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    StringRef drop_back(size_t N = 1) const noexcept {
-      assert(size() >= N && "Dropping more elements than exist");
-      return substr(0, size()-N);
-    }
-
-    /// Return a StringRef equal to 'this', but with all characters satisfying
-    /// the given predicate dropped from the beginning of the string.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    StringRef drop_while(function_ref<bool(char)> F) const noexcept {
-      return substr(find_if_not(F));
-    }
-
-    /// Return a StringRef equal to 'this', but with all characters not
-    /// satisfying the given predicate dropped from the beginning of the string.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    StringRef drop_until(function_ref<bool(char)> F) const noexcept {
-      return substr(find_if(F));
-    }
-
-    /// Returns true if this StringRef has the given prefix and removes that
-    /// prefix.
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    bool consume_front(StringRef Prefix) noexcept {
-      if (!startswith(Prefix))
-        return false;
-
-      *this = drop_front(Prefix.size());
-      return true;
-    }
-
-    /// Returns true if this StringRef has the given suffix and removes that
-    /// suffix.
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    bool consume_back(StringRef Suffix) noexcept {
-      if (!endswith(Suffix))
-        return false;
-
-      *this = drop_back(Suffix.size());
-      return true;
-    }
-
-    /// Return a reference to the substring from [Start, End).
-    ///
-    /// \param Start The index of the starting character in the substring; if
-    /// the index is npos or greater than the length of the string then the
-    /// empty substring will be returned.
-    ///
-    /// \param End The index following the last character to include in the
-    /// substring. If this is npos or exceeds the number of characters
-    /// remaining in the string, the string suffix (starting with \p Start)
-    /// will be returned. If this is less than \p Start, an empty string will
-    /// be returned.
-    LLVM_NODISCARD
-    LLVM_ATTRIBUTE_ALWAYS_INLINE
-    StringRef slice(size_t Start, size_t End) const noexcept {
-      Start = (std::min)(Start, Length);
-      End = (std::min)((std::max)(Start, End), Length);
-      return StringRef(Data + Start, End - Start);
-    }
-
-    /// Split into two substrings around the first occurrence of a separator
-    /// character.
-    ///
-    /// If \p Separator is in the string, then the result is a pair (LHS, RHS)
-    /// such that (*this == LHS + Separator + RHS) is true and RHS is
-    /// maximal. If \p Separator is not in the string, then the result is a
-    /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
-    ///
-    /// \param Separator The character to split on.
-    /// \returns The split substrings.
-    LLVM_NODISCARD
-    std::pair<StringRef, StringRef> split(char Separator) const {
-      return split(StringRef(&Separator, 1));
-    }
-
-    /// Split into two substrings around the first occurrence of a separator
-    /// string.
-    ///
-    /// If \p Separator is in the string, then the result is a pair (LHS, RHS)
-    /// such that (*this == LHS + Separator + RHS) is true and RHS is
-    /// maximal. If \p Separator is not in the string, then the result is a
-    /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
-    ///
-    /// \param Separator - The string to split on.
-    /// \return - The split substrings.
-    LLVM_NODISCARD
-    std::pair<StringRef, StringRef> split(StringRef Separator) const {
-      size_t Idx = find(Separator);
-      if (Idx == npos)
-        return std::make_pair(*this, StringRef());
-      return std::make_pair(slice(0, Idx), slice(Idx + Separator.size(), npos));
-    }
-
-    /// Split into two substrings around the last occurrence of a separator
-    /// string.
-    ///
-    /// If \p Separator is in the string, then the result is a pair (LHS, RHS)
-    /// such that (*this == LHS + Separator + RHS) is true and RHS is
-    /// minimal. If \p Separator is not in the string, then the result is a
-    /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
-    ///
-    /// \param Separator - The string to split on.
-    /// \return - The split substrings.
-    LLVM_NODISCARD
-    std::pair<StringRef, StringRef> rsplit(StringRef Separator) const {
-      size_t Idx = rfind(Separator);
-      if (Idx == npos)
-        return std::make_pair(*this, StringRef());
-      return std::make_pair(slice(0, Idx), slice(Idx + Separator.size(), npos));
-    }
-
-    /// Split into substrings around the occurrences of a separator string.
-    ///
-    /// Each substring is stored in \p A. If \p MaxSplit is >= 0, at most
-    /// \p MaxSplit splits are done and consequently <= \p MaxSplit + 1
-    /// elements are added to A.
-    /// If \p KeepEmpty is false, empty strings are not added to \p A. They
-    /// still count when considering \p MaxSplit
-    /// An useful invariant is that
-    /// Separator.join(A) == *this if MaxSplit == -1 and KeepEmpty == true
-    ///
-    /// \param A - Where to put the substrings.
-    /// \param Separator - The string to split on.
-    /// \param MaxSplit - The maximum number of times the string is split.
-    /// \param KeepEmpty - True if empty substring should be added.
-    void split(SmallVectorImpl<StringRef> &A,
-               StringRef Separator, int MaxSplit = -1,
-               bool KeepEmpty = true) const;
-
-    /// Split into substrings around the occurrences of a separator character.
-    ///
-    /// Each substring is stored in \p A. If \p MaxSplit is >= 0, at most
-    /// \p MaxSplit splits are done and consequently <= \p MaxSplit + 1
-    /// elements are added to A.
-    /// If \p KeepEmpty is false, empty strings are not added to \p A. They
-    /// still count when considering \p MaxSplit
-    /// An useful invariant is that
-    /// Separator.join(A) == *this if MaxSplit == -1 and KeepEmpty == true
-    ///
-    /// \param A - Where to put the substrings.
-    /// \param Separator - The string to split on.
-    /// \param MaxSplit - The maximum number of times the string is split.
-    /// \param KeepEmpty - True if empty substring should be added.
-    void split(SmallVectorImpl<StringRef> &A, char Separator, int MaxSplit = -1,
-               bool KeepEmpty = true) const;
-
-    /// Split into two substrings around the last occurrence of a separator
-    /// character.
-    ///
-    /// If \p Separator is in the string, then the result is a pair (LHS, RHS)
-    /// such that (*this == LHS + Separator + RHS) is true and RHS is
-    /// minimal. If \p Separator is not in the string, then the result is a
-    /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
-    ///
-    /// \param Separator - The character to split on.
-    /// \return - The split substrings.
-    LLVM_NODISCARD
-    std::pair<StringRef, StringRef> rsplit(char Separator) const {
-      return rsplit(StringRef(&Separator, 1));
-    }
-
-    /// Return string with consecutive \p Char characters starting from the
-    /// the left removed.
-    LLVM_NODISCARD
-    StringRef ltrim(char Char) const noexcept {
-      return drop_front((std::min)(Length, find_first_not_of(Char)));
-    }
-
-    /// Return string with consecutive characters in \p Chars starting from
-    /// the left removed.
-    LLVM_NODISCARD
-    StringRef ltrim(StringRef Chars = " \t\n\v\f\r") const noexcept {
-      return drop_front((std::min)(Length, find_first_not_of(Chars)));
-    }
-
-    /// Return string with consecutive \p Char characters starting from the
-    /// right removed.
-    LLVM_NODISCARD
-    StringRef rtrim(char Char) const noexcept {
-      return drop_back(size() - (std::min)(Length, find_last_not_of(Char) + 1));
-    }
-
-    /// Return string with consecutive characters in \p Chars starting from
-    /// the right removed.
-    LLVM_NODISCARD
-    StringRef rtrim(StringRef Chars = " \t\n\v\f\r") const noexcept {
-      return drop_back(size() - (std::min)(Length, find_last_not_of(Chars) + 1));
-    }
-
-    /// Return string with consecutive \p Char characters starting from the
-    /// left and right removed.
-    LLVM_NODISCARD
-    StringRef trim(char Char) const noexcept {
-      return ltrim(Char).rtrim(Char);
-    }
-
-    /// Return string with consecutive characters in \p Chars starting from
-    /// the left and right removed.
-    LLVM_NODISCARD
-    StringRef trim(StringRef Chars = " \t\n\v\f\r") const noexcept {
-      return ltrim(Chars).rtrim(Chars);
-    }
-
-    /// @}
-  };
-
-  /// A wrapper around a string literal that serves as a proxy for constructing
-  /// global tables of StringRefs with the length computed at compile time.
-  /// In order to avoid the invocation of a global constructor, StringLiteral
-  /// should *only* be used in a constexpr context, as such:
-  ///
-  /// constexpr StringLiteral S("test");
-  ///
-  class StringLiteral : public StringRef {
-  private:
-    constexpr StringLiteral(const char *Str, size_t N) : StringRef(Str, N) {
-    }
-
-  public:
-    template <size_t N>
-    constexpr StringLiteral(const char (&Str)[N])
-#if defined(__clang__) && __has_attribute(enable_if)
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wgcc-compat"
-        __attribute((enable_if(__builtin_strlen(Str) == N - 1,
-                               "invalid string literal")))
-#pragma clang diagnostic pop
-#endif
-        : StringRef(Str, N - 1) {
-    }
-
-    // Explicit construction for strings like "foo\0bar".
-    template <size_t N>
-    static constexpr StringLiteral withInnerNUL(const char (&Str)[N]) {
-      return StringLiteral(Str, N - 1);
-    }
-  };
-
-  /// @name StringRef Comparison Operators
-  /// @{
-
-  LLVM_ATTRIBUTE_ALWAYS_INLINE
-  bool operator==(StringRef LHS, StringRef RHS) noexcept {
-    return LHS.equals(RHS);
-  }
-
-  LLVM_ATTRIBUTE_ALWAYS_INLINE
-  bool operator!=(StringRef LHS, StringRef RHS) noexcept {
-    return !(LHS == RHS);
-  }
-
-  inline bool operator<(StringRef LHS, StringRef RHS) noexcept {
-    return LHS.compare(RHS) == -1;
-  }
-
-  inline bool operator<=(StringRef LHS, StringRef RHS) noexcept {
-    return LHS.compare(RHS) != 1;
-  }
-
-  inline bool operator>(StringRef LHS, StringRef RHS) noexcept {
-    return LHS.compare(RHS) == 1;
-  }
-
-  inline bool operator>=(StringRef LHS, StringRef RHS) noexcept {
-    return LHS.compare(RHS) != -1;
-  }
-
-  inline bool operator==(StringRef LHS, const char *RHS) noexcept {
-    return LHS.equals(StringRef(RHS));
-  }
-
-  inline bool operator!=(StringRef LHS, const char *RHS) noexcept {
-    return !(LHS == StringRef(RHS));
-  }
-
-  inline bool operator<(StringRef LHS, const char *RHS) noexcept {
-    return LHS.compare(StringRef(RHS)) == -1;
-  }
-
-  inline bool operator<=(StringRef LHS, const char *RHS) noexcept {
-    return LHS.compare(StringRef(RHS)) != 1;
-  }
-
-  inline bool operator>(StringRef LHS, const char *RHS) noexcept {
-    return LHS.compare(StringRef(RHS)) == 1;
-  }
-
-  inline bool operator>=(StringRef LHS, const char *RHS) noexcept {
-    return LHS.compare(StringRef(RHS)) != -1;
-  }
-
-  inline bool operator==(const char *LHS, StringRef RHS) noexcept {
-    return StringRef(LHS).equals(RHS);
-  }
-
-  inline bool operator!=(const char *LHS, StringRef RHS) noexcept {
-    return !(StringRef(LHS) == RHS);
-  }
-
-  inline bool operator<(const char *LHS, StringRef RHS) noexcept {
-    return StringRef(LHS).compare(RHS) == -1;
-  }
-
-  inline bool operator<=(const char *LHS, StringRef RHS) noexcept {
-    return StringRef(LHS).compare(RHS) != 1;
-  }
-
-  inline bool operator>(const char *LHS, StringRef RHS) noexcept {
-    return StringRef(LHS).compare(RHS) == 1;
-  }
-
-  inline bool operator>=(const char *LHS, StringRef RHS) noexcept {
-    return StringRef(LHS).compare(RHS) != -1;
-  }
-
-  inline std::string &operator+=(std::string &buffer, StringRef string) {
-    return buffer.append(string.data(), string.size());
-  }
-
-  std::ostream &operator<<(std::ostream &os, StringRef string);
-
-  /// @}
-
-  /// Compute a hash_code for a StringRef.
-  LLVM_NODISCARD
-  hash_code hash_value(StringRef S);
-
-  // StringRefs can be treated like a POD type.
-  template <typename T> struct isPodLike;
-  template <> struct isPodLike<StringRef> { static const bool value = true; };
-
-} // end namespace wpi
-
-#endif // LLVM_ADT_STRINGREF_H
diff --git a/wpiutil/src/main/native/include/wpi/TCPAcceptor.h b/wpiutil/src/main/native/include/wpi/TCPAcceptor.h
index f1ff685400..083897adac 100644
--- a/wpiutil/src/main/native/include/wpi/TCPAcceptor.h
+++ b/wpiutil/src/main/native/include/wpi/TCPAcceptor.h
@@ -27,6 +27,7 @@
 #include <atomic>
 #include <memory>
 #include <string>
+#include <string_view>
 
 #include "wpi/NetworkAcceptor.h"
 #include "wpi/TCPStream.h"
@@ -44,7 +45,7 @@ class TCPAcceptor : public NetworkAcceptor {
   Logger& m_logger;
 
  public:
-  TCPAcceptor(int port, const char* address, Logger& logger);
+  TCPAcceptor(int port, std::string_view address, Logger& logger);
   ~TCPAcceptor() override;
 
   int start() override;
diff --git a/wpiutil/src/main/native/include/wpi/TCPStream.h b/wpiutil/src/main/native/include/wpi/TCPStream.h
index 5b5f6405d9..2d54300029 100644
--- a/wpiutil/src/main/native/include/wpi/TCPStream.h
+++ b/wpiutil/src/main/native/include/wpi/TCPStream.h
@@ -26,6 +26,7 @@
 
 #include <cstddef>
 #include <string>
+#include <string_view>
 
 #include "wpi/NetworkStream.h"
 
@@ -50,7 +51,7 @@ class TCPStream : public NetworkStream {
                  int timeout = 0) override;
   void close() final;
 
-  StringRef getPeerIP() const override;
+  std::string_view getPeerIP() const override;
   int getPeerPort() const override;
   void setNoDelay() override;
   bool setBlocking(bool enabled) override;
diff --git a/wpiutil/src/main/native/include/wpi/Twine.h b/wpiutil/src/main/native/include/wpi/Twine.h
deleted file mode 100644
index e7d0f95c20..0000000000
--- a/wpiutil/src/main/native/include/wpi/Twine.h
+++ /dev/null
@@ -1,572 +0,0 @@
-//===- Twine.h - Fast Temporary String Concatenation ------------*- C++ -*-===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef WPIUTIL_WPI_TWINE_H
-#define WPIUTIL_WPI_TWINE_H
-
-#include "wpi/SmallVector.h"
-#include "wpi/StringRef.h"
-#include "wpi/ErrorHandling.h"
-#include <cassert>
-#include <cstdint>
-#include <string>
-#include <string_view>
-
-#ifdef _WIN32
-#pragma warning(push)
-#pragma warning(disable : 26495)
-#endif
-
-namespace wpi {
-
-  class raw_ostream;
-
-  /// Twine - A lightweight data structure for efficiently representing the
-  /// concatenation of temporary values as strings.
-  ///
-  /// A Twine is a kind of rope, it represents a concatenated string using a
-  /// binary-tree, where the string is the preorder of the nodes. Since the
-  /// Twine can be efficiently rendered into a buffer when its result is used,
-  /// it avoids the cost of generating temporary values for intermediate string
-  /// results -- particularly in cases when the Twine result is never
-  /// required. By explicitly tracking the type of leaf nodes, we can also avoid
-  /// the creation of temporary strings for conversions operations (such as
-  /// appending an integer to a string).
-  ///
-  /// A Twine is not intended for use directly and should not be stored, its
-  /// implementation relies on the ability to store pointers to temporary stack
-  /// objects which may be deallocated at the end of a statement. Twines should
-  /// only be used accepted as const references in arguments, when an API wishes
-  /// to accept possibly-concatenated strings.
-  ///
-  /// Twines support a special 'null' value, which always concatenates to form
-  /// itself, and renders as an empty string. This can be returned from APIs to
-  /// effectively nullify any concatenations performed on the result.
-  ///
-  /// \b Implementation
-  ///
-  /// Given the nature of a Twine, it is not possible for the Twine's
-  /// concatenation method to construct interior nodes; the result must be
-  /// represented inside the returned value. For this reason a Twine object
-  /// actually holds two values, the left- and right-hand sides of a
-  /// concatenation. We also have nullary Twine objects, which are effectively
-  /// sentinel values that represent empty strings.
-  ///
-  /// Thus, a Twine can effectively have zero, one, or two children. The \see
-  /// isNullary(), \see isUnary(), and \see isBinary() predicates exist for
-  /// testing the number of children.
-  ///
-  /// We maintain a number of invariants on Twine objects (FIXME: Why):
-  ///  - Nullary twines are always represented with their Kind on the left-hand
-  ///    side, and the Empty kind on the right-hand side.
-  ///  - Unary twines are always represented with the value on the left-hand
-  ///    side, and the Empty kind on the right-hand side.
-  ///  - If a Twine has another Twine as a child, that child should always be
-  ///    binary (otherwise it could have been folded into the parent).
-  ///
-  /// These invariants are check by \see isValid().
-  ///
-  /// \b Efficiency Considerations
-  ///
-  /// The Twine is designed to yield efficient and small code for common
-  /// situations. For this reason, the concat() method is inlined so that
-  /// concatenations of leaf nodes can be optimized into stores directly into a
-  /// single stack allocated object.
-  ///
-  /// In practice, not all compilers can be trusted to optimize concat() fully,
-  /// so we provide two additional methods (and accompanying operator+
-  /// overloads) to guarantee that particularly important cases (cstring plus
-  /// StringRef) codegen as desired.
-  class Twine {
-    /// NodeKind - Represent the type of an argument.
-    enum NodeKind : unsigned char {
-      /// An empty string; the result of concatenating anything with it is also
-      /// empty.
-      NullKind,
-
-      /// The empty string.
-      EmptyKind,
-
-      /// A pointer to a Twine instance.
-      TwineKind,
-
-      /// A pointer to a C string instance.
-      CStringKind,
-
-      /// A pointer to an std::string instance.
-      StdStringKind,
-
-      /// A pointer to a StringRef instance.
-      StringRefKind,
-
-      /// A pointer to a std::string_view instance.
-      StringViewKind,
-
-      /// A pointer to a SmallString instance.
-      SmallStringKind,
-
-      /// A char value, to render as a character.
-      CharKind,
-
-      /// An unsigned int value, to render as an unsigned decimal integer.
-      DecUIKind,
-
-      /// An int value, to render as a signed decimal integer.
-      DecIKind,
-
-      /// A pointer to an unsigned long value, to render as an unsigned decimal
-      /// integer.
-      DecULKind,
-
-      /// A pointer to a long value, to render as a signed decimal integer.
-      DecLKind,
-
-      /// A pointer to an unsigned long long value, to render as an unsigned
-      /// decimal integer.
-      DecULLKind,
-
-      /// A pointer to a long long value, to render as a signed decimal integer.
-      DecLLKind,
-
-      /// A pointer to a uint64_t value, to render as an unsigned hexadecimal
-      /// integer.
-      UHexKind
-    };
-
-    union Child
-    {
-      const Twine *twine;
-      const char *cString;
-      const std::string *stdString;
-      const StringRef *stringRef;
-      const std::string_view *stringView;
-      const SmallVectorImpl<char> *smallString;
-      char character;
-      unsigned int decUI;
-      int decI;
-      const unsigned long *decUL;
-      const long *decL;
-      const unsigned long long *decULL;
-      const long long *decLL;
-      const uint64_t *uHex;
-    };
-
-    /// LHS - The prefix in the concatenation, which may be uninitialized for
-    /// Null or Empty kinds.
-    Child LHS;
-
-    /// RHS - The suffix in the concatenation, which may be uninitialized for
-    /// Null or Empty kinds.
-    Child RHS;
-
-    /// LHSKind - The NodeKind of the left hand side, \see getLHSKind().
-    NodeKind LHSKind = EmptyKind;
-
-    /// RHSKind - The NodeKind of the right hand side, \see getRHSKind().
-    NodeKind RHSKind = EmptyKind;
-
-    /// Construct a nullary twine; the kind must be NullKind or EmptyKind.
-    explicit Twine(NodeKind Kind) : LHSKind(Kind) {
-      assert(isNullary() && "Invalid kind!");
-    }
-
-    /// Construct a binary twine.
-    explicit Twine(const Twine &LHS, const Twine &RHS)
-        : LHSKind(TwineKind), RHSKind(TwineKind) {
-      this->LHS.twine = &LHS;
-      this->RHS.twine = &RHS;
-      assert(isValid() && "Invalid twine!");
-    }
-
-    /// Construct a twine from explicit values.
-    explicit Twine(Child LHS, NodeKind LHSKind, Child RHS, NodeKind RHSKind)
-        : LHS(LHS), RHS(RHS), LHSKind(LHSKind), RHSKind(RHSKind) {
-      assert(isValid() && "Invalid twine!");
-    }
-
-    /// Check for the empty twine.
-    bool isEmpty() const {
-      return getLHSKind() == EmptyKind;
-    }
-
-    /// Check if this is a nullary twine (null or empty).
-    bool isNullary() const {
-      return isNull() || isEmpty();
-    }
-
-    /// Check if this is a unary twine.
-    bool isUnary() const {
-      return getRHSKind() == EmptyKind && !isNullary();
-    }
-
-    /// Check if this is a binary twine.
-    bool isBinary() const {
-      return getLHSKind() != NullKind && getRHSKind() != EmptyKind;
-    }
-
-    /// Check if this is a valid twine (satisfying the invariants on
-    /// order and number of arguments).
-    bool isValid() const {
-      // Nullary twines always have Empty on the RHS.
-      if (isNullary() && getRHSKind() != EmptyKind)
-        return false;
-
-      // Null should never appear on the RHS.
-      if (getRHSKind() == NullKind)
-        return false;
-
-      // The RHS cannot be non-empty if the LHS is empty.
-      if (getRHSKind() != EmptyKind && getLHSKind() == EmptyKind)
-        return false;
-#if 0 // causes spurious warnings
-      // A twine child should always be binary.
-      if (getLHSKind() == TwineKind &&
-          !LHS.twine->isBinary())
-        return false;
-      if (getRHSKind() == TwineKind &&
-          !RHS.twine->isBinary())
-        return false;
-#endif
-      return true;
-    }
-
-    /// Get the NodeKind of the left-hand side.
-    NodeKind getLHSKind() const { return LHSKind; }
-
-    /// Get the NodeKind of the right-hand side.
-    NodeKind getRHSKind() const { return RHSKind; }
-
-    /// Print one child from a twine.
-    void printOneChild(raw_ostream &OS, Child Ptr, NodeKind Kind) const;
-
-    /// Print the representation of one child from a twine.
-    void printOneChildRepr(raw_ostream &OS, Child Ptr,
-                           NodeKind Kind) const;
-
-  public:
-    /// @name Constructors
-    /// @{
-
-    /// Construct from an empty string.
-    /*implicit*/ Twine() {
-      assert(isValid() && "Invalid twine!");
-    }
-
-    Twine(const Twine &) = default;
-
-    /// Construct from a C string.
-    ///
-    /// We take care here to optimize "" into the empty twine -- this will be
-    /// optimized out for string constants. This allows Twine arguments have
-    /// default "" values, without introducing unnecessary string constants.
-    /*implicit*/ Twine(const char *Str) {
-      if (Str[0] != '\0') {
-        LHS.cString = Str;
-        LHSKind = CStringKind;
-      } else
-        LHSKind = EmptyKind;
-
-      assert(isValid() && "Invalid twine!");
-    }
-
-    /// Construct from an std::string.
-    /*implicit*/ Twine(const std::string &Str) : LHSKind(StdStringKind) {
-      LHS.stdString = &Str;
-      assert(isValid() && "Invalid twine!");
-    }
-
-    /// Construct from a StringRef.
-    /*implicit*/ Twine(const StringRef &Str) : LHSKind(StringRefKind) {
-      LHS.stringRef = &Str;
-      assert(isValid() && "Invalid twine!");
-    }
-
-    /// Construct from a std::string_view.
-    /*implicit*/ Twine(const std::string_view &Str) : LHSKind(StringViewKind) {
-      LHS.stringView = &Str;
-      assert(isValid() && "Invalid twine!");
-    }
-
-    /// Construct from a SmallString.
-    /*implicit*/ Twine(const SmallVectorImpl<char> &Str)
-        : LHSKind(SmallStringKind) {
-      LHS.smallString = &Str;
-      assert(isValid() && "Invalid twine!");
-    }
-
-    /// Construct from a char.
-    explicit Twine(char Val) : LHSKind(CharKind) {
-      LHS.character = Val;
-    }
-
-    /// Construct from a signed char.
-    explicit Twine(signed char Val) : LHSKind(CharKind) {
-      LHS.character = static_cast<char>(Val);
-    }
-
-    /// Construct from an unsigned char.
-    explicit Twine(unsigned char Val) : LHSKind(CharKind) {
-      LHS.character = static_cast<char>(Val);
-    }
-
-    /// Construct a twine to print \p Val as an unsigned decimal integer.
-    explicit Twine(unsigned Val) : LHSKind(DecUIKind) {
-      LHS.decUI = Val;
-    }
-
-    /// Construct a twine to print \p Val as a signed decimal integer.
-    explicit Twine(int Val) : LHSKind(DecIKind) {
-      LHS.decI = Val;
-    }
-
-    /// Construct a twine to print \p Val as an unsigned decimal integer.
-    explicit Twine(const unsigned long &Val) : LHSKind(DecULKind) {
-      LHS.decUL = &Val;
-    }
-
-    /// Construct a twine to print \p Val as a signed decimal integer.
-    explicit Twine(const long &Val) : LHSKind(DecLKind) {
-      LHS.decL = &Val;
-    }
-
-    /// Construct a twine to print \p Val as an unsigned decimal integer.
-    explicit Twine(const unsigned long long &Val) : LHSKind(DecULLKind) {
-      LHS.decULL = &Val;
-    }
-
-    /// Construct a twine to print \p Val as a signed decimal integer.
-    explicit Twine(const long long &Val) : LHSKind(DecLLKind) {
-      LHS.decLL = &Val;
-    }
-
-    // FIXME: Unfortunately, to make sure this is as efficient as possible we
-    // need extra binary constructors from particular types. We can't rely on
-    // the compiler to be smart enough to fold operator+()/concat() down to the
-    // right thing. Yet.
-
-    /// Construct as the concatenation of a C string and a StringRef.
-    /*implicit*/ Twine(const char *LHS, const StringRef &RHS)
-        : LHSKind(CStringKind), RHSKind(StringRefKind) {
-      this->LHS.cString = LHS;
-      this->RHS.stringRef = &RHS;
-      assert(isValid() && "Invalid twine!");
-    }
-
-    /// Construct as the concatenation of a StringRef and a C string.
-    /*implicit*/ Twine(const StringRef &LHS, const char *RHS)
-        : LHSKind(StringRefKind), RHSKind(CStringKind) {
-      this->LHS.stringRef = &LHS;
-      this->RHS.cString = RHS;
-      assert(isValid() && "Invalid twine!");
-    }
-
-    /// Construct as the concatenation of a C string and a std::string_view.
-    /*implicit*/ Twine(const char *LHS, const std::string_view &RHS)
-        : LHSKind(CStringKind), RHSKind(StringViewKind) {
-      this->LHS.cString = LHS;
-      this->RHS.stringView = &RHS;
-      assert(isValid() && "Invalid twine!");
-    }
-
-    /// Construct as the concatenation of a std::string_view and a C string.
-    /*implicit*/ Twine(const std::string_view &LHS, const char *RHS)
-        : LHSKind(StringViewKind), RHSKind(CStringKind) {
-      this->LHS.stringView = &LHS;
-      this->RHS.cString = RHS;
-      assert(isValid() && "Invalid twine!");
-    }
-
-    /// Since the intended use of twines is as temporary objects, assignments
-    /// when concatenating might cause undefined behavior or stack corruptions
-    Twine &operator=(const Twine &) = delete;
-
-    /// Create a 'null' string, which is an empty string that always
-    /// concatenates to form another empty string.
-    static Twine createNull() {
-      return Twine(NullKind);
-    }
-
-    /// @}
-    /// @name Numeric Conversions
-    /// @{
-
-    // Construct a twine to print \p Val as an unsigned hexadecimal integer.
-    static Twine utohexstr(const uint64_t &Val) {
-      Child LHS, RHS;
-      LHS.uHex = &Val;
-      RHS.twine = nullptr;
-      return Twine(LHS, UHexKind, RHS, EmptyKind);
-    }
-
-    /// @}
-    /// @name Predicate Operations
-    /// @{
-
-    /// Check for the null twine.
-    bool isNull() const {
-      return getLHSKind() == NullKind;
-    }
-
-    /// Check if this twine is trivially empty; a false return value does not
-    /// necessarily mean the twine is empty.
-    bool isTriviallyEmpty() const {
-      return isNullary();
-    }
-
-    /// Return true if this twine can be dynamically accessed as a single
-    /// StringRef value with getSingleStringRef().
-    bool isSingleStringRef() const {
-      if (getRHSKind() != EmptyKind) return false;
-
-      switch (getLHSKind()) {
-      case EmptyKind:
-      case CStringKind:
-      case StdStringKind:
-      case StringRefKind:
-      case StringViewKind:
-      case SmallStringKind:
-      case CharKind:
-        return true;
-      default:
-        return false;
-      }
-    }
-
-    /// @}
-    /// @name String Operations
-    /// @{
-
-    Twine concat(const Twine &Suffix) const;
-
-    /// @}
-    /// @name Output & Conversion.
-    /// @{
-
-    /// Return the twine contents as a std::string.
-    std::string str() const;
-
-    /// Append the concatenated string into the given SmallString or SmallVector.
-    void toVector(SmallVectorImpl<char> &Out) const;
-
-    /// This returns the twine as a single StringRef.  This method is only valid
-    /// if isSingleStringRef() is true.
-    StringRef getSingleStringRef() const {
-      assert(isSingleStringRef() &&"This cannot be had as a single stringref!");
-      switch (getLHSKind()) {
-      default:
-        // unreachable("Out of sync with isSingleStringRef");
-        return StringRef();
-      case EmptyKind:      return StringRef();
-      case CStringKind:    return StringRef(LHS.cString);
-      case StdStringKind:  return StringRef(*LHS.stdString);
-      case StringRefKind:  return *LHS.stringRef;
-      case StringViewKind: return StringRef(*LHS.stringView);
-      case SmallStringKind:
-        return StringRef(LHS.smallString->data(), LHS.smallString->size());
-      case CharKind:       return StringRef(&LHS.character, 1);
-      }
-    }
-
-    /// This returns the twine as a single StringRef if it can be
-    /// represented as such. Otherwise the twine is written into the given
-    /// SmallVector and a StringRef to the SmallVector's data is returned.
-    StringRef toStringRef(SmallVectorImpl<char> &Out) const {
-      if (isSingleStringRef())
-        return getSingleStringRef();
-      toVector(Out);
-      return StringRef(Out.data(), Out.size());
-    }
-
-    /// This returns the twine as a single null terminated StringRef if it
-    /// can be represented as such. Otherwise the twine is written into the
-    /// given SmallVector and a StringRef to the SmallVector's data is returned.
-    ///
-    /// The returned StringRef's size does not include the null terminator.
-    StringRef toNullTerminatedStringRef(SmallVectorImpl<char> &Out) const;
-
-    /// Write the concatenated string represented by this twine to the
-    /// stream \p OS.
-    void print(raw_ostream &OS) const;
-
-    /// Dump the concatenated string represented by this twine to stderr.
-    void dump() const;
-
-    /// Write the representation of this twine to the stream \p OS.
-    void printRepr(raw_ostream &OS) const;
-
-    /// Dump the representation of this twine to stderr.
-    void dumpRepr() const;
-
-    /// @}
-  };
-
-  /// @name Twine Inline Implementations
-  /// @{
-
-  inline Twine Twine::concat(const Twine &Suffix) const {
-    // Concatenation with null is null.
-    if (isNull() || Suffix.isNull())
-      return Twine(NullKind);
-
-    // Concatenation with empty yields the other side.
-    if (isEmpty())
-      return Suffix;
-    if (Suffix.isEmpty())
-      return *this;
-
-    // Otherwise we need to create a new node, taking care to fold in unary
-    // twines.
-    Child NewLHS, NewRHS;
-    NewLHS.twine = this;
-    NewRHS.twine = &Suffix;
-    NodeKind NewLHSKind = TwineKind, NewRHSKind = TwineKind;
-    if (isUnary()) {
-      NewLHS = LHS;
-      NewLHSKind = getLHSKind();
-    }
-    if (Suffix.isUnary()) {
-      NewRHS = Suffix.LHS;
-      NewRHSKind = Suffix.getLHSKind();
-    }
-
-    return Twine(NewLHS, NewLHSKind, NewRHS, NewRHSKind);
-  }
-
-  inline Twine operator+(const Twine &LHS, const Twine &RHS) {
-    return LHS.concat(RHS);
-  }
-
-  /// Additional overload to guarantee simplified codegen; this is equivalent to
-  /// concat().
-
-  inline Twine operator+(const char *LHS, const StringRef &RHS) {
-    return Twine(LHS, RHS);
-  }
-
-  /// Additional overload to guarantee simplified codegen; this is equivalent to
-  /// concat().
-
-  inline Twine operator+(const StringRef &LHS, const char *RHS) {
-    return Twine(LHS, RHS);
-  }
-
-  inline raw_ostream &operator<<(raw_ostream &OS, const Twine &RHS) {
-    RHS.print(OS);
-    return OS;
-  }
-
-  /// @}
-
-} // end namespace wpi
-
-#ifdef _WIN32
-#pragma warning(pop)
-#endif
-
-#endif // LLVM_ADT_TWINE_H
diff --git a/wpiutil/src/main/native/include/wpi/UDPClient.h b/wpiutil/src/main/native/include/wpi/UDPClient.h
index 493c6ed832..ec06c8ce97 100644
--- a/wpiutil/src/main/native/include/wpi/UDPClient.h
+++ b/wpiutil/src/main/native/include/wpi/UDPClient.h
@@ -6,11 +6,10 @@
 #define WPIUTIL_WPI_UDPCLIENT_H_
 
 #include <string>
+#include <string_view>
 
 #include "wpi/ArrayRef.h"
 #include "wpi/SmallVector.h"
-#include "wpi/StringRef.h"
-#include "wpi/Twine.h"
 #include "wpi/mutex.h"
 
 namespace wpi {
@@ -25,7 +24,7 @@ class UDPClient {
 
  public:
   explicit UDPClient(Logger& logger);
-  UDPClient(const Twine& address, Logger& logger);
+  UDPClient(std::string_view address, Logger& logger);
   UDPClient(const UDPClient& other) = delete;
   UDPClient(UDPClient&& other);
   ~UDPClient();
@@ -37,8 +36,8 @@ class UDPClient {
   int start(int port);
   void shutdown();
   // The passed in address MUST be a resolved IP address.
-  int send(ArrayRef<uint8_t> data, const Twine& server, int port);
-  int send(StringRef data, const Twine& server, int port);
+  int send(ArrayRef<uint8_t> data, std::string_view server, int port);
+  int send(std::string_view data, std::string_view server, int port);
   int receive(uint8_t* data_received, int receive_len);
   int receive(uint8_t* data_received, int receive_len,
               SmallVectorImpl<char>* addr_received, int* port_received);
diff --git a/wpiutil/src/main/native/include/wpi/UrlParser.h b/wpiutil/src/main/native/include/wpi/UrlParser.h
index 790d1f76a6..3b6107bcdf 100644
--- a/wpiutil/src/main/native/include/wpi/UrlParser.h
+++ b/wpiutil/src/main/native/include/wpi/UrlParser.h
@@ -5,7 +5,8 @@
 #ifndef WPIUTIL_WPI_URLPARSER_H_
 #define WPIUTIL_WPI_URLPARSER_H_
 
-#include "wpi/StringRef.h"
+#include <string_view>
+
 #include "wpi/http_parser.h"
 
 namespace wpi {
@@ -21,7 +22,7 @@ class UrlParser {
    * @param in input
    * @param isConnect
    */
-  UrlParser(StringRef in, bool isConnect) {
+  UrlParser(std::string_view in, bool isConnect) {
     m_data = in;
     http_parser_url_init(&m_url);
     m_error = http_parser_parse_url(in.data(), in.size(), isConnect, &m_url);
@@ -50,41 +51,41 @@ class UrlParser {
     return (m_url.field_set & (1 << UF_USERINFO)) != 0;
   }
 
-  StringRef GetSchema() const {
+  std::string_view GetSchema() const {
     return m_data.substr(m_url.field_data[UF_SCHEMA].off,
                          m_url.field_data[UF_SCHEMA].len);
   }
 
-  StringRef GetHost() const {
+  std::string_view GetHost() const {
     return m_data.substr(m_url.field_data[UF_HOST].off,
                          m_url.field_data[UF_HOST].len);
   }
 
   unsigned int GetPort() const { return m_url.port; }
 
-  StringRef GetPath() const {
+  std::string_view GetPath() const {
     return m_data.substr(m_url.field_data[UF_PATH].off,
                          m_url.field_data[UF_PATH].len);
   }
 
-  StringRef GetQuery() const {
+  std::string_view GetQuery() const {
     return m_data.substr(m_url.field_data[UF_QUERY].off,
                          m_url.field_data[UF_QUERY].len);
   }
 
-  StringRef GetFragment() const {
+  std::string_view GetFragment() const {
     return m_data.substr(m_url.field_data[UF_FRAGMENT].off,
                          m_url.field_data[UF_FRAGMENT].len);
   }
 
-  StringRef GetUserInfo() const {
+  std::string_view GetUserInfo() const {
     return m_data.substr(m_url.field_data[UF_USERINFO].off,
                          m_url.field_data[UF_USERINFO].len);
   }
 
  private:
   bool m_error;
-  StringRef m_data;
+  std::string_view m_data;
   http_parser_url m_url;
 };
 
diff --git a/wpiutil/src/main/native/include/wpi/VersionTuple.h b/wpiutil/src/main/native/include/wpi/VersionTuple.h
index e54ca924f5..59df41ccab 100644
--- a/wpiutil/src/main/native/include/wpi/VersionTuple.h
+++ b/wpiutil/src/main/native/include/wpi/VersionTuple.h
@@ -15,11 +15,8 @@
 #ifndef WPIUTIL_WPI_VERSIONTUPLE_H
 #define WPIUTIL_WPI_VERSIONTUPLE_H
 
-#include "wpi/StringRef.h"
-#include "wpi/raw_ostream.h"
 #include <optional>
 #include <string>
-#include <tuple>
 
 namespace wpi {
 
@@ -137,18 +134,7 @@ public:
   friend bool operator>=(const VersionTuple &X, const VersionTuple &Y) {
     return !(X < Y);
   }
-
-  /// Retrieve a string representation of the version number.
-  std::string getAsString() const;
-
-  /// Try to parse the given string as a version number.
-  /// \returns \c true if the string does not match the regular expression
-  ///   [0-9]+(\.[0-9]+){0,3}
-  bool tryParse(StringRef string);
 };
 
-/// Print a version number.
-raw_ostream &operator<<(raw_ostream &Out, const VersionTuple &V);
-
 } // end namespace wpi
 #endif // WPIUTIL_WPI_VERSIONTUPLE_H
diff --git a/wpiutil/src/main/native/include/wpi/WebSocket.h b/wpiutil/src/main/native/include/wpi/WebSocket.h
index 54dedb145f..a86481908c 100644
--- a/wpiutil/src/main/native/include/wpi/WebSocket.h
+++ b/wpiutil/src/main/native/include/wpi/WebSocket.h
@@ -11,13 +11,12 @@
 #include <initializer_list>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <utility>
 
 #include "wpi/ArrayRef.h"
 #include "wpi/Signal.h"
 #include "wpi/SmallVector.h"
-#include "wpi/StringRef.h"
-#include "wpi/Twine.h"
 #include "wpi/uv/Buffer.h"
 #include "wpi/uv/Error.h"
 #include "wpi/uv/Timer.h"
@@ -79,7 +78,7 @@ class WebSocket : public std::enable_shared_from_this<WebSocket> {
     uv::Timer::Time handshakeTimeout;  // NOLINT
 
     /** Additional headers to include in handshake. */
-    ArrayRef<std::pair<StringRef, StringRef>> extraHeaders;
+    ArrayRef<std::pair<std::string_view, std::string_view>> extraHeaders;
   };
 
   /**
@@ -93,9 +92,9 @@ class WebSocket : public std::enable_shared_from_this<WebSocket> {
    * @param options Handshake options
    */
   static std::shared_ptr<WebSocket> CreateClient(
-      uv::Stream& stream, const Twine& uri, const Twine& host,
-      ArrayRef<StringRef> protocols = ArrayRef<StringRef>{},
-      const ClientOptions& options = ClientOptions{});
+      uv::Stream& stream, std::string_view uri, std::string_view host,
+      ArrayRef<std::string_view> protocols = {},
+      const ClientOptions& options = {});
 
   /**
    * Starts a client connection by performing the initial client handshake.
@@ -108,9 +107,9 @@ class WebSocket : public std::enable_shared_from_this<WebSocket> {
    * @param options Handshake options
    */
   static std::shared_ptr<WebSocket> CreateClient(
-      uv::Stream& stream, const Twine& uri, const Twine& host,
-      std::initializer_list<StringRef> protocols,
-      const ClientOptions& options = ClientOptions{}) {
+      uv::Stream& stream, std::string_view uri, std::string_view host,
+      std::initializer_list<std::string_view> protocols,
+      const ClientOptions& options = {}) {
     return CreateClient(stream, uri, host,
                         makeArrayRef(protocols.begin(), protocols.end()),
                         options);
@@ -130,8 +129,8 @@ class WebSocket : public std::enable_shared_from_this<WebSocket> {
    *                 Sec-WebSocket-Protocol header field).
    */
   static std::shared_ptr<WebSocket> CreateServer(
-      uv::Stream& stream, StringRef key, StringRef version,
-      StringRef protocol = StringRef{});
+      uv::Stream& stream, std::string_view key, std::string_view version,
+      std::string_view protocol = {});
 
   /**
    * Get connection state.
@@ -152,7 +151,7 @@ class WebSocket : public std::enable_shared_from_this<WebSocket> {
   /**
    * Get the selected sub-protocol.  Only valid in or after the open() event.
    */
-  StringRef GetProtocol() const { return m_protocol; }
+  std::string_view GetProtocol() const { return m_protocol; }
 
   /**
    * Set the maximum message size.  Default is 128 KB.  If configured to combine
@@ -176,7 +175,7 @@ class WebSocket : public std::enable_shared_from_this<WebSocket> {
    * @param reason A human-readable string explaining why the connection is
    *               closing (optional).
    */
-  void Close(uint16_t code = 1005, const Twine& reason = Twine{});
+  void Close(uint16_t code = 1005, std::string_view reason = {});
 
   /**
    * Send a text message.
@@ -292,12 +291,12 @@ class WebSocket : public std::enable_shared_from_this<WebSocket> {
   /**
    * Fail the connection.
    */
-  void Fail(uint16_t code = 1002, const Twine& reason = "protocol error");
+  void Fail(uint16_t code = 1002, std::string_view reason = "protocol error");
 
   /**
    * Forcibly close the connection.
    */
-  void Terminate(uint16_t code = 1006, const Twine& reason = "terminated");
+  void Terminate(uint16_t code = 1006, std::string_view reason = "terminated");
 
   /**
    * Gets user-defined data.
@@ -318,7 +317,7 @@ class WebSocket : public std::enable_shared_from_this<WebSocket> {
    * Open event.  Emitted when the connection is open and ready to communicate.
    * The parameter is the selected subprotocol.
    */
-  sig::Signal<StringRef> open;
+  sig::Signal<std::string_view> open;
 
   /**
    * Close event.  Emitted when the connection is closed.  The first parameter
@@ -326,14 +325,14 @@ class WebSocket : public std::enable_shared_from_this<WebSocket> {
    * has been closed.  The second parameter is a human-readable string
    * explaining the reason why the connection has been closed.
    */
-  sig::Signal<uint16_t, StringRef> closed;
+  sig::Signal<uint16_t, std::string_view> closed;
 
   /**
    * Text message event.  Emitted when a text message is received.
    * The first parameter is the data, the second parameter is true if the
    * data is the last fragment of the message.
    */
-  sig::Signal<StringRef, bool> text;
+  sig::Signal<std::string_view, bool> text;
 
   /**
    * Binary message event.  Emitted when a binary message is received.
@@ -382,11 +381,13 @@ class WebSocket : public std::enable_shared_from_this<WebSocket> {
   class ClientHandshakeData;
   std::unique_ptr<ClientHandshakeData> m_clientHandshake;
 
-  void StartClient(const Twine& uri, const Twine& host,
-                   ArrayRef<StringRef> protocols, const ClientOptions& options);
-  void StartServer(StringRef key, StringRef version, StringRef protocol);
-  void SendClose(uint16_t code, const Twine& reason);
-  void SetClosed(uint16_t code, const Twine& reason, bool failed = false);
+  void StartClient(std::string_view uri, std::string_view host,
+                   ArrayRef<std::string_view> protocols,
+                   const ClientOptions& options);
+  void StartServer(std::string_view key, std::string_view version,
+                   std::string_view protocol);
+  void SendClose(uint16_t code, std::string_view reason);
+  void SetClosed(uint16_t code, std::string_view reason, bool failed = false);
   void Shutdown();
   void HandleIncoming(uv::Buffer& buf, size_t size);
   void Send(
diff --git a/wpiutil/src/main/native/include/wpi/WebSocketServer.h b/wpiutil/src/main/native/include/wpi/WebSocketServer.h
index f911cb438f..afae8f03ae 100644
--- a/wpiutil/src/main/native/include/wpi/WebSocketServer.h
+++ b/wpiutil/src/main/native/include/wpi/WebSocketServer.h
@@ -9,6 +9,7 @@
 #include <initializer_list>
 #include <memory>
 #include <string>
+#include <string_view>
 #include <utility>
 
 #include "wpi/ArrayRef.h"
@@ -16,7 +17,6 @@
 #include "wpi/Signal.h"
 #include "wpi/SmallString.h"
 #include "wpi/SmallVector.h"
-#include "wpi/StringRef.h"
 #include "wpi/WebSocket.h"
 
 namespace wpi {
@@ -52,7 +52,8 @@ class WebSocketServerHelper {
    *         Second item is the matched protocol if a match was made, otherwise
    *         is empty.
    */
-  std::pair<bool, StringRef> MatchProtocol(ArrayRef<StringRef> protocols);
+  std::pair<bool, std::string_view> MatchProtocol(
+      ArrayRef<std::string_view> protocols);
 
   /**
    * Try to find a match to the list of sub-protocols provided by the client.
@@ -63,8 +64,8 @@ class WebSocketServerHelper {
    *         Second item is the matched protocol if a match was made, otherwise
    *         is empty.
    */
-  std::pair<bool, StringRef> MatchProtocol(
-      std::initializer_list<StringRef> protocols) {
+  std::pair<bool, std::string_view> MatchProtocol(
+      std::initializer_list<std::string_view> protocols) {
     return MatchProtocol(makeArrayRef(protocols.begin(), protocols.end()));
   }
 
@@ -75,7 +76,7 @@ class WebSocketServerHelper {
    * @param protocol The subprotocol to send to the client
    */
   std::shared_ptr<WebSocket> Accept(uv::Stream& stream,
-                                    StringRef protocol = StringRef{}) {
+                                    std::string_view protocol = {}) {
     return WebSocket::CreateServer(stream, m_key, m_version, protocol);
   }
 
@@ -109,19 +110,19 @@ class WebSocketServer : public std::enable_shared_from_this<WebSocketServer> {
      * Checker for URL.  Return true if URL should be accepted.  By default all
      * URLs are accepted.
      */
-    std::function<bool(StringRef)> checkUrl;
+    std::function<bool(std::string_view)> checkUrl;
 
     /**
      * Checker for Host header.  Return true if Host should be accepted.  By
      * default all hosts are accepted.
      */
-    std::function<bool(StringRef)> checkHost;
+    std::function<bool(std::string_view)> checkHost;
   };
 
   /**
    * Private constructor.
    */
-  WebSocketServer(uv::Stream& stream, ArrayRef<StringRef> protocols,
+  WebSocketServer(uv::Stream& stream, ArrayRef<std::string_view> protocols,
                   ServerOptions options, const private_init&);
 
   /**
@@ -134,8 +135,8 @@ class WebSocketServer : public std::enable_shared_from_this<WebSocketServer> {
    * @param options Handshake options
    */
   static std::shared_ptr<WebSocketServer> Create(
-      uv::Stream& stream, ArrayRef<StringRef> protocols = ArrayRef<StringRef>{},
-      const ServerOptions& options = ServerOptions{});
+      uv::Stream& stream, ArrayRef<std::string_view> protocols = {},
+      const ServerOptions& options = {});
 
   /**
    * Starts a dedicated WebSocket server on the provided connection.  The
@@ -147,8 +148,8 @@ class WebSocketServer : public std::enable_shared_from_this<WebSocketServer> {
    * @param options Handshake options
    */
   static std::shared_ptr<WebSocketServer> Create(
-      uv::Stream& stream, std::initializer_list<StringRef> protocols,
-      const ServerOptions& options = ServerOptions{}) {
+      uv::Stream& stream, std::initializer_list<std::string_view> protocols,
+      const ServerOptions& options = {}) {
     return Create(stream, makeArrayRef(protocols.begin(), protocols.end()),
                   options);
   }
@@ -156,7 +157,7 @@ class WebSocketServer : public std::enable_shared_from_this<WebSocketServer> {
   /**
    * Connected event.  First parameter is the URL, second is the websocket.
    */
-  sig::Signal<StringRef, WebSocket&> connected;
+  sig::Signal<std::string_view, WebSocket&> connected;
 
  private:
   uv::Stream& m_stream;
@@ -169,7 +170,7 @@ class WebSocketServer : public std::enable_shared_from_this<WebSocketServer> {
   sig::ScopedConnection m_errorConn;
   sig::ScopedConnection m_endConn;
 
-  void Abort(uint16_t code, StringRef reason);
+  void Abort(uint16_t code, std::string_view reason);
 };
 
 }  // namespace wpi
diff --git a/wpiutil/src/main/native/include/wpi/fmt/raw_ostream.h b/wpiutil/src/main/native/include/wpi/fmt/raw_ostream.h
new file mode 100644
index 0000000000..8779bfc521
--- /dev/null
+++ b/wpiutil/src/main/native/include/wpi/fmt/raw_ostream.h
@@ -0,0 +1,30 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#ifndef WPIUTIL_WPI_FMT_RAW_OSTREAM_H_
+#define WPIUTIL_WPI_FMT_RAW_OSTREAM_H_
+
+#include "fmt/format.h"
+#include "wpi/raw_ostream.h"
+
+FMT_BEGIN_NAMESPACE
+
+inline void vprint(wpi::raw_ostream& os, string_view format_str,
+                   fmt::format_args args) {
+  memory_buffer buffer;
+  detail::vformat_to(buffer, format_str, args);
+  os.write(buffer.data(), buffer.size());
+}
+
+/**
+ * Prints formatted data to the stream *os*.
+ */
+template <typename S, typename... Args>
+void print(wpi::raw_ostream& os, const S& format_str, Args&&... args) {
+  vprint(os, format_str, fmt::make_args_checked<Args...>(format_str, args...));
+}
+
+FMT_END_NAMESPACE
+
+#endif  // WPIUTIL_WPI_FMT_RAW_OSTREAM_H_
diff --git a/wpiutil/src/main/native/include/wpi/hostname.h b/wpiutil/src/main/native/include/wpi/hostname.h
index 7702674138..bd93b4a0db 100644
--- a/wpiutil/src/main/native/include/wpi/hostname.h
+++ b/wpiutil/src/main/native/include/wpi/hostname.h
@@ -6,15 +6,14 @@
 #define WPIUTIL_WPI_HOSTNAME_H_
 
 #include <string>
-
-#include "wpi/StringRef.h"
+#include <string_view>
 
 namespace wpi {
 template <typename T>
 class SmallVectorImpl;
 
 std::string GetHostname();
-StringRef GetHostname(SmallVectorImpl<char>& name);
+std::string_view GetHostname(SmallVectorImpl<char>& name);
 }  // namespace wpi
 
 #endif  // WPIUTIL_WPI_HOSTNAME_H_
diff --git a/wpiutil/src/main/native/include/wpi/jni_util.h b/wpiutil/src/main/native/include/wpi/jni_util.h
index 11e8f542c2..129a5b7200 100644
--- a/wpiutil/src/main/native/include/wpi/jni_util.h
+++ b/wpiutil/src/main/native/include/wpi/jni_util.h
@@ -9,6 +9,7 @@
 
 #include <queue>
 #include <string>
+#include <string_view>
 #include <type_traits>
 #include <utility>
 #include <vector>
@@ -18,7 +19,7 @@
 #include "wpi/SafeThread.h"
 #include "wpi/SmallString.h"
 #include "wpi/SmallVector.h"
-#include "wpi/StringRef.h"
+#include "wpi/StringExtras.h"
 #include "wpi/deprecated.h"
 #include "wpi/mutex.h"
 #include "wpi/raw_ostream.h"
@@ -30,7 +31,7 @@ namespace wpi::java {
 // in the stack trace not starting with excludeFuncPrefix (useful for e.g.
 // finding the first user call to a series of library functions).
 std::string GetJavaStackTrace(JNIEnv* env, std::string* func = nullptr,
-                              StringRef excludeFuncPrefix = StringRef());
+                              std::string_view excludeFuncPrefix = {});
 
 // Finds a class and keep it as a global reference.
 // Use with caution, as the destructor does NOT call DeleteGlobalRef due
@@ -148,8 +149,8 @@ class JStringRef {
     m_str.pop_back();
   }
 
-  operator StringRef() const { return m_str; }  // NOLINT
-  StringRef str() const { return m_str; }
+  operator std::string_view() const { return m_str.str(); }  // NOLINT
+  std::string_view str() const { return m_str.str(); }
   const char* c_str() const { return m_str.data(); }
   size_t size() const { return m_str.size(); }
 
@@ -163,18 +164,18 @@ namespace detail {
 template <typename C, typename T>
 class JArrayRefInner {};
 
-// Specialization of JArrayRefBase to provide StringRef conversion.
+// Specialization of JArrayRefBase to provide std::string_view conversion.
 template <typename C>
 class JArrayRefInner<C, jbyte> {
  public:
-  operator StringRef() const { return str(); }
+  operator std::string_view() const { return str(); }
 
-  StringRef str() const {
+  std::string_view str() const {
     auto arr = static_cast<const C*>(this)->array();
     if (arr.empty()) {
       return {};
     }
-    return StringRef{reinterpret_cast<const char*>(arr.data()), arr.size()};
+    return {reinterpret_cast<const char*>(arr.data()), arr.size()};
   }
 };
 
@@ -326,7 +327,7 @@ WPI_JNI_JARRAYREF(jdouble, Double)
 //
 
 // Convert a UTF8 string into a jstring.
-inline jstring MakeJString(JNIEnv* env, StringRef str) {
+inline jstring MakeJString(JNIEnv* env, std::string_view str) {
   SmallVector<UTF16, 128> chars;
   convertUTF8ToUTF16String(str, chars);
   return env->NewString(chars.begin(), chars.size());
@@ -395,8 +396,8 @@ inline jintArray MakeJIntArray(JNIEnv* env, const std::vector<T>& arr) {
   return detail::ConvertIntArray<T>::ToJava(env, arr);
 }
 
-// Convert a StringRef into a jbyteArray.
-inline jbyteArray MakeJByteArray(JNIEnv* env, StringRef str) {
+// Convert a std::string_view into a jbyteArray.
+inline jbyteArray MakeJByteArray(JNIEnv* env, std::string_view str) {
   jbyteArray jarr = env->NewByteArray(str.size());
   if (!jarr) {
     return nullptr;
@@ -593,7 +594,7 @@ class JSingletonCallbackManager : public JCallbackManager<T> {
   }
 };
 
-inline std::string GetJavaStackTrace(JNIEnv* env, StringRef skipPrefix) {
+inline std::string GetJavaStackTrace(JNIEnv* env, std::string_view skipPrefix) {
   // create a throwable
   static JClass throwableCls(env, "java/lang/Throwable");
   if (!throwableCls) {
@@ -657,7 +658,7 @@ inline std::string GetJavaStackTrace(JNIEnv* env, StringRef skipPrefix) {
     // add a line to res
     JStringRef elem(env, stackElementString);
     if (!foundFirst) {
-      if (elem.str().startswith(skipPrefix)) {
+      if (wpi::starts_with(elem, skipPrefix)) {
         continue;
       }
       foundFirst = true;
@@ -669,7 +670,7 @@ inline std::string GetJavaStackTrace(JNIEnv* env, StringRef skipPrefix) {
 }
 
 inline std::string GetJavaStackTrace(JNIEnv* env, std::string* func,
-                                     StringRef excludeFuncPrefix) {
+                                     std::string_view excludeFuncPrefix) {
   // create a throwable
   static JClass throwableCls(env, "java/lang/Throwable");
   if (!throwableCls) {
@@ -740,7 +741,7 @@ inline std::string GetJavaStackTrace(JNIEnv* env, std::string* func,
       if (i == 1) {
         *func = elem.str();
       } else if (i > 1 && !haveLoc && !excludeFuncPrefix.empty() &&
-                 !elem.str().startswith(excludeFuncPrefix)) {
+                 !wpi::starts_with(elem, excludeFuncPrefix)) {
         *func = elem.str();
         haveLoc = true;
       }
@@ -769,7 +770,9 @@ class JException : public JClass {
     env->Throw(static_cast<jthrowable>(exception));
   }
 
-  void Throw(JNIEnv* env, StringRef msg) { Throw(env, MakeJString(env, msg)); }
+  void Throw(JNIEnv* env, std::string_view msg) {
+    Throw(env, MakeJString(env, msg));
+  }
 
   explicit operator bool() const { return m_constructor; }
 
diff --git a/wpiutil/src/main/native/include/wpi/json.h b/wpiutil/src/main/native/include/wpi/json.h
index a6368b7c05..873e2e5712 100644
--- a/wpiutil/src/main/native/include/wpi/json.h
+++ b/wpiutil/src/main/native/include/wpi/json.h
@@ -54,6 +54,7 @@ SOFTWARE.
 #include <memory> // allocator, shared_ptr, make_shared, addressof
 #include <stdexcept> // runtime_error
 #include <string> // string, char_traits, stoi, to_string
+#include <string_view>
 #include <tuple> // tuple, get, make_tuple
 #include <type_traits>
 #include <utility>
@@ -61,8 +62,6 @@ SOFTWARE.
 
 #include "wpi/ArrayRef.h"
 #include "wpi/StringMap.h"
-#include "wpi/StringRef.h"
-#include "wpi/Twine.h"
 
 namespace wpi
 {
@@ -239,7 +238,7 @@ template<class RealType, class CompatibleObjectType>
 struct is_compatible_object_type_impl<true, RealType, CompatibleObjectType>
 {
     static constexpr auto value =
-        std::is_constructible<StringRef, typename CompatibleObjectType::key_type>::value and
+        std::is_constructible<std::string_view, typename CompatibleObjectType::key_type>::value and
         std::is_constructible<typename RealType::mapped_type, typename CompatibleObjectType::mapped_type>::value;
 };
 
@@ -269,7 +268,7 @@ struct is_compatible_array_type
         std::conjunction<std::negation<std::is_same<void, CompatibleArrayType>>,
         std::negation<is_compatible_object_type<
         BasicJsonType, CompatibleArrayType>>,
-        std::negation<std::is_constructible<StringRef,
+        std::negation<std::is_constructible<std::string_view,
         CompatibleArrayType>>,
         std::negation<is_json_nested_type<BasicJsonType, CompatibleArrayType>>,
         has_value_type<CompatibleArrayType>,
@@ -423,7 +422,7 @@ class exception : public std::exception
     const int id;
 
   protected:
-    exception(int id_, const Twine& what_arg);
+    exception(int id_, std::string_view what_arg);
 
   private:
     /// an exception object as storage for error messages
@@ -484,7 +483,7 @@ class parse_error : public exception
     @param[in] what_arg  the explanatory string
     @return parse_error object
     */
-    static parse_error create(int id_, std::size_t byte_, const Twine& what_arg);
+    static parse_error create(int id_, std::size_t byte_, std::string_view what_arg);
 
     /*!
     @brief byte index of the parse error
@@ -498,7 +497,7 @@ class parse_error : public exception
     const std::size_t byte;
 
   private:
-    parse_error(int id_, std::size_t byte_, const Twine& what_arg)
+    parse_error(int id_, std::size_t byte_, std::string_view what_arg)
         : exception(id_, what_arg), byte(byte_) {}
 };
 
@@ -542,10 +541,11 @@ caught.,invalid_iterator}
 class invalid_iterator : public exception
 {
   public:
-    static invalid_iterator create(int id_, const Twine& what_arg);
+    static invalid_iterator create(int id_, std::string_view what_arg);
+    static invalid_iterator create(int id_, std::string_view what_arg, std::string_view type_info);
 
   private:
-    invalid_iterator(int id_, const Twine& what_arg)
+    invalid_iterator(int id_, std::string_view what_arg)
         : exception(id_, what_arg) {}
 };
 
@@ -590,10 +590,11 @@ caught.,type_error}
 class type_error : public exception
 {
   public:
-    static type_error create(int id_, const Twine& what_arg);
+    static type_error create(int id_, std::string_view what_arg);
+    static type_error create(int id_, std::string_view what_arg, std::string_view type_info);
 
   private:
-    type_error(int id_, const Twine& what_arg) : exception(id_, what_arg) {}
+    type_error(int id_, std::string_view what_arg) : exception(id_, what_arg) {}
 };
 
 /*!
@@ -631,10 +632,10 @@ caught.,out_of_range}
 class out_of_range : public exception
 {
   public:
-    static out_of_range create(int id_, const Twine& what_arg);
+    static out_of_range create(int id_, std::string_view what_arg);
 
   private:
-    out_of_range(int id_, const Twine& what_arg) : exception(id_, what_arg) {}
+    out_of_range(int id_, std::string_view what_arg) : exception(id_, what_arg) {}
 };
 
 /*!
@@ -664,10 +665,10 @@ caught.,other_error}
 class other_error : public exception
 {
   public:
-    static other_error create(int id_, const Twine& what_arg);
+    static other_error create(int id_, std::string_view what_arg);
 
   private:
-    other_error(int id_, const Twine& what_arg) : exception(id_, what_arg) {}
+    other_error(int id_, std::string_view what_arg) : exception(id_, what_arg) {}
 };
 
 ///////////////////////////
@@ -760,7 +761,7 @@ void get_arithmetic_value(const BasicJsonType& j, ArithmeticType& val)
         }
 
         default:
-            JSON_THROW(type_error::create(302, "type must be number, but is " + Twine(j.type_name())));
+            JSON_THROW(type_error::create(302, "type must be number, but is", j.type_name()));
     }
 }
 
@@ -769,7 +770,7 @@ void from_json(const BasicJsonType& j, bool& b)
 {
     if (JSON_UNLIKELY(not j.is_boolean()))
     {
-        JSON_THROW(type_error::create(302, "type must be boolean, but is " + Twine(j.type_name())));
+        JSON_THROW(type_error::create(302, "type must be boolean, but is", j.type_name()));
     }
     b = *j.template get_ptr<const bool*>();
 }
@@ -779,7 +780,7 @@ void from_json(const BasicJsonType& j, std::string& s)
 {
     if (JSON_UNLIKELY(not j.is_string()))
     {
-        JSON_THROW(type_error::create(302, "type must be string, but is " + Twine(j.type_name())));
+        JSON_THROW(type_error::create(302, "type must be string, but is", j.type_name()));
     }
     s = *j.template get_ptr<const std::string*>();
 }
@@ -816,7 +817,7 @@ void from_json(const BasicJsonType& j, typename BasicJsonType::array_t& arr)
 {
     if (JSON_UNLIKELY(not j.is_array()))
     {
-        JSON_THROW(type_error::create(302, "type must be array, but is " + Twine(j.type_name())));
+        JSON_THROW(type_error::create(302, "type must be array, but is", j.type_name()));
     }
     arr = *j.template get_ptr<const typename BasicJsonType::array_t*>();
 }
@@ -875,8 +876,7 @@ void from_json(const BasicJsonType& j, CompatibleArrayType& arr)
 {
     if (JSON_UNLIKELY(not j.is_array()))
     {
-        JSON_THROW(type_error::create(302, "type must be array, but is " +
-                                      Twine(j.type_name())));
+        JSON_THROW(type_error::create(302, "type must be array, but is", j.type_name()));
     }
 
     from_json_array_impl(j, arr, priority_tag<2> {});
@@ -888,7 +888,7 @@ void from_json(const BasicJsonType& j, typename BasicJsonType::object_t& obj)
 {
     if (!j.is_object())
     {
-        JSON_THROW(type_error::create(302, "type must be object, but is " + Twine(j.type_name())));
+        JSON_THROW(type_error::create(302, "type must be object, but is", j.type_name()));
     }
 
     auto inner_object = j.template get_ptr<const typename BasicJsonType::object_t*>();
@@ -904,7 +904,7 @@ void from_json(const BasicJsonType& j, CompatibleObjectType& obj)
 {
     if (JSON_UNLIKELY(not j.is_object()))
     {
-        JSON_THROW(type_error::create(302, "type must be object, but is " + Twine(j.type_name())));
+        JSON_THROW(type_error::create(302, "type must be object, but is", j.type_name()));
     }
 
     auto inner_object = j.template get_ptr<const typename BasicJsonType::object_t*>();
@@ -965,7 +965,7 @@ void from_json(const BasicJsonType& j, ArithmeticType& val)
         }
 
         default:
-            JSON_THROW(type_error::create(302, "type must be number, but is " + Twine(j.type_name())));
+            JSON_THROW(type_error::create(302, "type must be number, but is", j.type_name()));
     }
 }
 
@@ -1053,7 +1053,7 @@ template<>
 struct external_constructor<value_t::string>
 {
     template<typename BasicJsonType>
-    static void construct(BasicJsonType& j, StringRef s)
+    static void construct(BasicJsonType& j, std::string_view s)
     {
         j.m_type = value_t::string;
         j.m_value = s;
@@ -1206,7 +1206,7 @@ void to_json(BasicJsonType& j, T b) noexcept
 }
 
 template<typename BasicJsonType, typename CompatibleString,
-         enable_if_t<std::is_constructible<StringRef, CompatibleString>::value, int> = 0>
+         enable_if_t<std::is_constructible<std::string_view, CompatibleString>::value, int> = 0>
 void to_json(BasicJsonType& j, const CompatibleString& s)
 {
     external_constructor<value_t::string>::construct(j, s);
@@ -1283,7 +1283,7 @@ void to_json(BasicJsonType& j, typename BasicJsonType::object_t&& obj)
 }
 
 template<typename BasicJsonType, typename T, std::size_t N,
-         enable_if_t<not std::is_constructible<StringRef, T (&)[N]>::value, int> = 0>
+         enable_if_t<not std::is_constructible<std::string_view, T (&)[N]>::value, int> = 0>
 void to_json(BasicJsonType& j, T (&arr)[N])
 {
     external_constructor<value_t::array>::construct(j, arr);
@@ -2044,7 +2044,7 @@ class iter_impl
     @brief  return the key of an object iterator
     @pre The iterator is initialized; i.e. `m_object != nullptr`.
     */
-    StringRef key() const
+    std::string_view key() const
     {
         assert(m_object != nullptr);
 
@@ -2348,7 +2348,7 @@ class json_pointer
 
     @since version 2.0.0
     */
-    explicit json_pointer(const Twine& s = {})
+    explicit json_pointer(std::string_view s = {})
         : reference_tokens(split(s))
     {}
 
@@ -2382,7 +2382,7 @@ class json_pointer
 
     @throw out_of_range.404 if string @a s could not be converted to an integer
     */
-    static int array_index(const Twine& s);
+    static int array_index(std::string_view s);
 
   private:
     /*!
@@ -2490,7 +2490,7 @@ class json_pointer
     @throw parse_error.107  if the pointer is not empty or begins with '/'
     @throw parse_error.108  if character '~' is not followed by '0' or '1'
     */
-    static std::vector<std::string> split(const Twine& reference_string);
+    static std::vector<std::string> split(std::string_view reference_string);
 
     /*!
     @brief replace all occurrences of a substring by another string
@@ -2521,7 +2521,7 @@ class json_pointer
 
     @note Empty objects or arrays are flattened to `null`.
     */
-    static void flatten(const Twine& reference_string,
+    static void flatten(std::string_view reference_string,
                         const json& value,
                         json& result);
 
@@ -2970,7 +2970,7 @@ class json
         json_value(value_t t);
 
         /// constructor for strings
-        json_value(StringRef value)
+        json_value(std::string_view value)
         {
             string = create<std::string>(value);
         }
@@ -3576,8 +3576,7 @@ class json
             }
 
             default:
-                JSON_THROW(invalid_iterator::create(206, "cannot construct with iterators from " +
-                                                    Twine(first.m_object->type_name())));
+                JSON_THROW(invalid_iterator::create(206, "cannot construct with iterators from", first.m_object->type_name()));
         }
 
         assert_invariant();
@@ -4162,7 +4161,7 @@ class json
             return m_value.boolean;
         }
 
-        JSON_THROW(type_error::create(302, "type must be boolean, but is " + Twine(type_name())));
+        JSON_THROW(type_error::create(302, "type must be boolean, but is", type_name()));
     }
 
     /// get a pointer to the value (object)
@@ -4271,7 +4270,7 @@ class json
             return *ptr;
         }
 
-        JSON_THROW(type_error::create(303, "incompatible ReferenceType for get_ref, actual type is " + Twine(obj.type_name())));
+        JSON_THROW(type_error::create(303, "incompatible ReferenceType for get_ref, actual type is", obj.type_name()));
     }
 
   public:
@@ -4716,7 +4715,7 @@ class json
     written using `at()`. It also demonstrates the different exceptions that
     can be thrown.,at__object_t_key_type}
     */
-    reference at(StringRef key);
+    reference at(std::string_view key);
 
     /*!
     @brief access specified object element with bounds checking
@@ -4748,7 +4747,7 @@ class json
     `at()`. It also demonstrates the different exceptions that can be thrown.,
     at__object_t_key_type_const}
     */
-    const_reference at(StringRef key) const;
+    const_reference at(std::string_view key) const;
 
     /*!
     @brief access specified array element
@@ -4825,7 +4824,7 @@ class json
 
     @since version 1.0.0
     */
-    reference operator[](StringRef key);
+    reference operator[](std::string_view key);
 
     /*!
     @brief read-only access specified object element
@@ -4857,7 +4856,7 @@ class json
 
     @since version 1.0.0
     */
-    const_reference operator[](StringRef key) const;
+    const_reference operator[](std::string_view key) const;
 
     /*!
     @brief access specified object element
@@ -4903,7 +4902,7 @@ class json
             return m_value.object->operator[](key);
         }
 
-        JSON_THROW(type_error::create(305, "cannot use operator[] with " + Twine(type_name())));
+        JSON_THROW(type_error::create(305, "cannot use operator[] with", type_name()));
     }
 
     /*!
@@ -4946,7 +4945,7 @@ class json
             return m_value.object->find(key)->second;
         }
 
-        JSON_THROW(type_error::create(305, "cannot use operator[] with " + Twine(type_name())));
+        JSON_THROW(type_error::create(305, "cannot use operator[] with", type_name()));
     }
 
     /*!
@@ -4999,7 +4998,7 @@ class json
     */
     template<class ValueType, typename std::enable_if<
                  std::is_convertible<json_t, ValueType>::value, int>::type = 0>
-    ValueType value(StringRef key, const ValueType& default_value) const
+    ValueType value(std::string_view key, const ValueType& default_value) const
     {
         // at only works for objects
         if (JSON_LIKELY(is_object()))
@@ -5014,14 +5013,14 @@ class json
             return default_value;
         }
 
-        JSON_THROW(type_error::create(306, "cannot use value() with " + Twine(type_name())));
+        JSON_THROW(type_error::create(306, "cannot use value() with", type_name()));
     }
 
     /*!
     @brief overload for a default value of type const char*
     @copydoc json::value(const typename object_t::key_type&, ValueType) const
     */
-    std::string value(StringRef key, const char* default_value) const
+    std::string value(std::string_view key, const char* default_value) const
     {
         return value(key, std::string(default_value));
     }
@@ -5085,7 +5084,7 @@ class json
             }
         }
 
-        JSON_THROW(type_error::create(306, "cannot use value() with " + Twine(type_name())));
+        JSON_THROW(type_error::create(306, "cannot use value() with", type_name()));
     }
 
     /*!
@@ -5220,7 +5219,7 @@ class json
 
     @sa @ref erase(IteratorType, IteratorType) -- removes the elements in
     the given range
-    @sa @ref erase(StringRef) -- removes the element
+    @sa @ref erase(std::string_view) -- removes the element
     from an object at the given key
     @sa @ref erase(const size_type) -- removes the element from an array at
     the given index
@@ -5278,7 +5277,7 @@ class json
             }
 
             default:
-                JSON_THROW(type_error::create(307, "cannot use erase() with " + Twine(type_name())));
+                JSON_THROW(type_error::create(307, "cannot use erase() with", type_name()));
         }
     }
 
@@ -5377,7 +5376,7 @@ class json
             }
 
             default:
-                JSON_THROW(type_error::create(307, "cannot use erase() with " + Twine(type_name())));
+                JSON_THROW(type_error::create(307, "cannot use erase() with", type_name()));
         }
 
         return result;
@@ -5412,7 +5411,7 @@ class json
 
     @since version 1.0.0
     */
-    size_type erase(StringRef key);
+    size_type erase(std::string_view key);
 
     /*!
     @brief remove element from a JSON array given an index
@@ -5472,13 +5471,13 @@ class json
 
     @since version 1.0.0
     */
-    iterator find(StringRef key);
+    iterator find(std::string_view key);
 
     /*!
     @brief find an element in a JSON object
     @copydoc find(KeyT&&)
     */
-    const_iterator find(StringRef key) const;
+    const_iterator find(std::string_view key) const;
 
     /*!
     @brief returns the number of occurrences of a key in a JSON object
@@ -5501,7 +5500,7 @@ class json
 
     @since version 1.0.0
     */
-    size_type count(StringRef key) const;
+    size_type count(std::string_view key) const;
 
     /// @}
 
@@ -6113,7 +6112,7 @@ class json
         // push_back only works for null objects or objects
         if (JSON_UNLIKELY(not(is_null() or is_object())))
         {
-            JSON_THROW(type_error::create(308, "cannot use push_back() with " + Twine(type_name())));
+            JSON_THROW(type_error::create(308, "cannot use push_back() with", type_name()));
         }
 
         // transform null object into an object
@@ -6203,7 +6202,7 @@ class json
         // emplace_back only works for null objects or arrays
         if (JSON_UNLIKELY(not(is_null() or is_array())))
         {
-            JSON_THROW(type_error::create(311, "cannot use emplace_back() with " + Twine(type_name())));
+            JSON_THROW(type_error::create(311, "cannot use emplace_back() with", type_name()));
         }
 
         // transform null object into an array
@@ -6246,12 +6245,12 @@ class json
     @since version 2.0.8
     */
     template<class... Args>
-    std::pair<iterator, bool> emplace(StringRef key, Args&& ... args)
+    std::pair<iterator, bool> emplace(std::string_view key, Args&& ... args)
     {
         // emplace only works for null objects or arrays
         if (JSON_UNLIKELY(not(is_null() or is_object())))
         {
-            JSON_THROW(type_error::create(311, "cannot use emplace() with " + Twine(type_name())));
+            JSON_THROW(type_error::create(311, "cannot use emplace() with", type_name()));
         }
 
         // transform null object into an object
@@ -6521,7 +6520,7 @@ class json
         }
         else
         {
-            JSON_THROW(type_error::create(310, "cannot use swap() with " + Twine(type_name())));
+            JSON_THROW(type_error::create(310, "cannot use swap() with", type_name()));
         }
     }
 
@@ -6554,7 +6553,7 @@ class json
         }
         else
         {
-            JSON_THROW(type_error::create(310, "cannot use swap() with " + Twine(type_name())));
+            JSON_THROW(type_error::create(310, "cannot use swap() with", type_name()));
         }
     }
 
@@ -6587,7 +6586,7 @@ class json
         }
         else
         {
-            JSON_THROW(type_error::create(310, "cannot use swap() with " + Twine(type_name())));
+            JSON_THROW(type_error::create(310, "cannot use swap() with", type_name()));
         }
     }
 
@@ -7011,7 +7010,7 @@ class json
 
     @since version 2.0.3 (contiguous containers)
     */
-    static json parse(StringRef s,
+    static json parse(std::string_view s,
                             const parser_callback_t cb = nullptr,
                             const bool allow_exceptions = true);
 
@@ -7026,7 +7025,7 @@ class json
                             const parser_callback_t cb = nullptr,
                             const bool allow_exceptions = true);
 
-    static bool accept(StringRef s);
+    static bool accept(std::string_view s);
 
     static bool accept(ArrayRef<uint8_t> arr);
 
@@ -8074,7 +8073,7 @@ if no parse error occurred.
 */
 inline wpi::json operator "" _json(const char* s, std::size_t n)
 {
-    return wpi::json::parse(wpi::StringRef(s, n));
+    return wpi::json::parse(std::string_view(s, n));
 }
 
 /*!
@@ -8092,7 +8091,7 @@ object if no parse error occurred.
 */
 inline wpi::json::json_pointer operator "" _json_pointer(const char* s, std::size_t n)
 {
-    return wpi::json::json_pointer(wpi::StringRef(s, n));
+    return wpi::json::json_pointer(std::string_view(s, n));
 }
 
 #ifndef WPI_JSON_IMPLEMENTATION
diff --git a/wpiutil/src/main/native/include/wpi/raw_istream.h b/wpiutil/src/main/native/include/wpi/raw_istream.h
index d09f82f08b..aab3866ad9 100644
--- a/wpiutil/src/main/native/include/wpi/raw_istream.h
+++ b/wpiutil/src/main/native/include/wpi/raw_istream.h
@@ -10,13 +10,12 @@
 #include <algorithm>
 #include <cstddef>
 #include <string>
+#include <string_view>
 #include <system_error>
 #include <vector>
 
 #include "wpi/ArrayRef.h"
 #include "wpi/SmallVector.h"
-#include "wpi/StringRef.h"
-#include "wpi/Twine.h"
 
 namespace wpi {
 
@@ -100,7 +99,7 @@ class raw_istream {
   // @param buf Buffer for output
   // @param maxLen Maximum length
   // @return Line
-  StringRef getline(SmallVectorImpl<char>& buf, int maxLen);
+  std::string_view getline(SmallVectorImpl<char>& buf, int maxLen);
 
   virtual void close() = 0;
 
@@ -154,7 +153,7 @@ class raw_mem_istream : public raw_istream {
 
 class raw_fd_istream : public raw_istream {
  public:
-  raw_fd_istream(const Twine& filename, std::error_code& ec,
+  raw_fd_istream(std::string_view filename, std::error_code& ec,
                  size_t bufSize = 4096);
   raw_fd_istream(int fd, bool shouldClose, size_t bufSize = 4096);
   ~raw_fd_istream() override;
diff --git a/wpiutil/src/main/native/include/wpi/raw_ostream.h b/wpiutil/src/main/native/include/wpi/raw_ostream.h
index 517090979d..7e4a0c1c14 100644
--- a/wpiutil/src/main/native/include/wpi/raw_ostream.h
+++ b/wpiutil/src/main/native/include/wpi/raw_ostream.h
@@ -16,7 +16,6 @@
 
 #include "wpi/ArrayRef.h"
 #include "wpi/SmallVector.h"
-#include "wpi/StringRef.h"
 #include <cassert>
 #include <cstddef>
 #include <cstdint>
@@ -34,11 +33,6 @@ enum CreationDisposition : unsigned;
 
 namespace wpi {
 
-class format_object_base;
-class FormattedString;
-class FormattedNumber;
-class FormattedBytes;
-
 /// This class implements an extremely fast bulk output stream that can *only*
 /// output to a stream.  It does not support seeking, reopening, rewinding, line
 /// buffered disciplines etc. It is a simple buffer that outputs
@@ -180,21 +174,6 @@ public:
     return *this;
   }
 
-  raw_ostream &operator<<(StringRef Str) {
-    // Inline fast path, particularly for strings with a known length.
-    size_t Size = Str.size();
-
-    // Make sure we can use the fast path.
-    if (Size > (size_t)(OutBufEnd - OutBufCur))
-      return write(Str.data(), Size);
-
-    if (Size) {
-      memcpy(OutBufCur, Str.data(), Size);
-      OutBufCur += Size;
-    }
-    return *this;
-  }
-
   raw_ostream &operator<<(std::string_view Str) {
     // Inline fast path, particularly for strings with a known length.
     size_t Size = Str.size();
@@ -214,7 +193,7 @@ public:
     // Inline fast path, particularly for constant strings where a sufficiently
     // smart compiler will simplify strlen.
 
-    return this->operator<<(StringRef(Str));
+    return this->operator<<(std::string_view(Str));
   }
 
   raw_ostream &operator<<(const std::string &Str) {
@@ -235,28 +214,9 @@ public:
     return write(Arr.data(), Arr.size());
   }
 
-  raw_ostream &operator<<(unsigned long N);
-  raw_ostream &operator<<(long N);
-  raw_ostream &operator<<(unsigned long long N);
-  raw_ostream &operator<<(long long N);
-  raw_ostream &operator<<(const void *P);
-
-  raw_ostream &operator<<(unsigned int N) {
-    return this->operator<<(static_cast<unsigned long>(N));
-  }
-
-  raw_ostream &operator<<(int N) {
-    return this->operator<<(static_cast<long>(N));
-  }
-
-  raw_ostream &operator<<(double N);
-
-  /// Output \p N in hexadecimal, without any prefix or padding.
-  raw_ostream &write_hex(unsigned long long N);
-
   /// Output \p Str, turning '\\', '\t', '\n', '"', and anything that doesn't
   /// satisfy wpi::isPrint into an escape sequence.
-  raw_ostream &write_escaped(StringRef Str, bool UseHexEscapes = false);
+  raw_ostream &write_escaped(std::string_view Str, bool UseHexEscapes = false);
 
   raw_ostream &write(unsigned char C);
   raw_ostream &write(const char *Ptr, size_t Size);
@@ -264,18 +224,6 @@ public:
     return write(reinterpret_cast<const char *>(Ptr), Size);
   }
 
-  // Formatted output, see the format() function in Support/Format.h.
-  raw_ostream &operator<<(const format_object_base &Fmt);
-
-  // Formatted output, see the leftJustify() function in Support/Format.h.
-  raw_ostream &operator<<(const FormattedString &);
-
-  // Formatted output, see the formatHex() function in Support/Format.h.
-  raw_ostream &operator<<(const FormattedNumber &);
-
-  // Formatted output, see the format_bytes() function in Support/Format.h.
-  raw_ostream &operator<<(const FormattedBytes &);
-
   /// indent - Insert 'NumSpaces' spaces.
   raw_ostream &indent(unsigned NumSpaces);
 
@@ -443,14 +391,14 @@ public:
   /// As a special case, if Filename is "-", then the stream will use
   /// STDOUT_FILENO instead of opening a file. This will not close the stdout
   /// descriptor.
-  raw_fd_ostream(StringRef Filename, std::error_code &EC);
-  raw_fd_ostream(StringRef Filename, std::error_code &EC,
+  raw_fd_ostream(std::string_view Filename, std::error_code &EC);
+  raw_fd_ostream(std::string_view Filename, std::error_code &EC,
                  fs::CreationDisposition Disp);
-  raw_fd_ostream(StringRef Filename, std::error_code &EC,
+  raw_fd_ostream(std::string_view Filename, std::error_code &EC,
                  fs::FileAccess Access);
-  raw_fd_ostream(StringRef Filename, std::error_code &EC,
+  raw_fd_ostream(std::string_view Filename, std::error_code &EC,
                  fs::OpenFlags Flags);
-  raw_fd_ostream(StringRef Filename, std::error_code &EC,
+  raw_fd_ostream(std::string_view Filename, std::error_code &EC,
                  fs::CreationDisposition Disp, fs::FileAccess Access,
                  fs::OpenFlags Flags);
 
@@ -559,8 +507,8 @@ public:
 
   void flush() = delete;
 
-  /// Return a StringRef for the vector contents.
-  StringRef str() { return StringRef(OS.data(), OS.size()); }
+  /// Return a std::string_view for the vector contents.
+  std::string_view str() { return std::string_view(OS.data(), OS.size()); }
 };
 
 /// A raw_ostream that writes to a vector.  This is a
@@ -592,8 +540,8 @@ public:
 
   void flush() = delete;
 
-  /// Return a StringRef for the vector contents.
-  StringRef str() { return StringRef(OS.data(), OS.size()); }
+  /// Return a std::string_view for the vector contents.
+  std::string_view str() { return std::string_view(OS.data(), OS.size()); }
 };
 
 /// A raw_ostream that writes to an SmallVector or SmallString.  This is a
@@ -658,7 +606,7 @@ public:
 
   void flush() = delete;
 
-  /// Return a StringRef for the vector contents.
+  /// Return a ArrayRef for the vector contents.
   ArrayRef<uint8_t> array() { return ArrayRef<uint8_t>(OS.data(), OS.size()); }
 };
 
diff --git a/wpiutil/src/main/native/include/wpi/sha1.h b/wpiutil/src/main/native/include/wpi/sha1.h
index 6a0817f915..75464bfdf6 100644
--- a/wpiutil/src/main/native/include/wpi/sha1.h
+++ b/wpiutil/src/main/native/include/wpi/sha1.h
@@ -23,8 +23,7 @@
 #include <stdint.h>
 
 #include <string>
-
-#include "wpi/StringRef.h"
+#include <string_view>
 
 namespace wpi {
 template <typename T>
@@ -34,12 +33,12 @@ class raw_istream;
 class SHA1 {
  public:
   SHA1();
-  void Update(StringRef s);
+  void Update(std::string_view s);
   void Update(raw_istream& is);
   std::string Final();
-  StringRef Final(SmallVectorImpl<char>& buf);
-  StringRef RawFinal(SmallVectorImpl<char>& buf);
-  static std::string FromFile(StringRef filename);
+  std::string_view Final(SmallVectorImpl<char>& buf);
+  std::string_view RawFinal(SmallVectorImpl<char>& buf);
+  static std::string FromFile(std::string_view filename);
 
  private:
   uint32_t digest[5];
diff --git a/wpiutil/src/main/native/include/wpi/uv/Buffer.h b/wpiutil/src/main/native/include/wpi/uv/Buffer.h
index 80ea168885..cd47b6c8e9 100644
--- a/wpiutil/src/main/native/include/wpi/uv/Buffer.h
+++ b/wpiutil/src/main/native/include/wpi/uv/Buffer.h
@@ -9,11 +9,11 @@
 
 #include <cstring>
 #include <initializer_list>
+#include <string_view>
 #include <utility>
 
 #include "wpi/ArrayRef.h"
 #include "wpi/SmallVector.h"
-#include "wpi/StringRef.h"
 
 namespace wpi::uv {
 
@@ -30,7 +30,7 @@ class Buffer : public uv_buf_t {
     base = oth.base;
     len = oth.len;
   }
-  /*implicit*/ Buffer(StringRef str)  // NOLINT
+  /*implicit*/ Buffer(std::string_view str)  // NOLINT
       : Buffer{str.data(), str.size()} {}
   /*implicit*/ Buffer(ArrayRef<uint8_t> arr)  // NOLINT
       : Buffer{reinterpret_cast<const char*>(arr.data()), arr.size()} {}
@@ -51,7 +51,7 @@ class Buffer : public uv_buf_t {
 
   static Buffer Allocate(size_t size) { return Buffer{new char[size], size}; }
 
-  static Buffer Dup(StringRef in) {
+  static Buffer Dup(std::string_view in) {
     Buffer buf = Allocate(in.size());
     std::memcpy(buf.base, in.data(), in.size());
     return buf;
diff --git a/wpiutil/src/main/native/include/wpi/uv/FsEvent.h b/wpiutil/src/main/native/include/wpi/uv/FsEvent.h
index 0eb70743e9..0ed2dcbe92 100644
--- a/wpiutil/src/main/native/include/wpi/uv/FsEvent.h
+++ b/wpiutil/src/main/native/include/wpi/uv/FsEvent.h
@@ -9,9 +9,9 @@
 
 #include <memory>
 #include <string>
+#include <string_view>
 
 #include "wpi/Signal.h"
-#include "wpi/Twine.h"
 #include "wpi/uv/Handle.h"
 
 namespace wpi::uv {
@@ -51,7 +51,7 @@ class FsEvent final : public HandleImpl<FsEvent, uv_fs_event_t> {
    * @param events Bitmask of event flags.  Only UV_FS_EVENT_RECURSIVE is
    *               supported (and only on OSX and Windows).
    */
-  void Start(const Twine& path, unsigned int flags = 0);
+  void Start(std::string_view path, unsigned int flags = 0);
 
   /**
    * Stop watching for changes.
diff --git a/wpiutil/src/main/native/include/wpi/uv/GetAddrInfo.h b/wpiutil/src/main/native/include/wpi/uv/GetAddrInfo.h
index f1606e2f5b..8f085099a6 100644
--- a/wpiutil/src/main/native/include/wpi/uv/GetAddrInfo.h
+++ b/wpiutil/src/main/native/include/wpi/uv/GetAddrInfo.h
@@ -9,9 +9,9 @@
 
 #include <functional>
 #include <memory>
+#include <string_view>
 
 #include "wpi/Signal.h"
-#include "wpi/Twine.h"
 #include "wpi/uv/Request.h"
 
 namespace wpi::uv {
@@ -40,7 +40,7 @@ class GetAddrInfoReq : public RequestImpl<GetAddrInfoReq, uv_getaddrinfo_t> {
  * request when the resolution completes.  HandleError() is called on the
  * request if any errors occur.
  *
- * Either node or service may be null (`Twine::createNull()`) but not both.
+ * Either node or service may be empty but not both.
  *
  * @param loop Event loop
  * @param req request
@@ -50,7 +50,7 @@ class GetAddrInfoReq : public RequestImpl<GetAddrInfoReq, uv_getaddrinfo_t> {
  *              type constraints.
  */
 void GetAddrInfo(Loop& loop, const std::shared_ptr<GetAddrInfoReq>& req,
-                 const Twine& node, const Twine& service = Twine::createNull(),
+                 std::string_view node, std::string_view service = {},
                  const addrinfo* hints = nullptr);
 
 /**
@@ -58,7 +58,7 @@ void GetAddrInfo(Loop& loop, const std::shared_ptr<GetAddrInfoReq>& req,
  * request when the resolution completes.  HandleError() is called on the
  * request if any errors occur.
  *
- * Either node or service may be null (`Twine::createNull()`) but not both.
+ * Either node or service may be empty but not both.
  *
  * @param loop Event loop
  * @param req request
@@ -69,8 +69,7 @@ void GetAddrInfo(Loop& loop, const std::shared_ptr<GetAddrInfoReq>& req,
  */
 inline void GetAddrInfo(const std::shared_ptr<Loop>& loop,
                         const std::shared_ptr<GetAddrInfoReq>& req,
-                        const Twine& node,
-                        const Twine& service = Twine::createNull(),
+                        std::string_view node, std::string_view service = {},
                         const addrinfo* hints = nullptr) {
   GetAddrInfo(*loop, req, node, service, hints);
 }
@@ -80,7 +79,7 @@ inline void GetAddrInfo(const std::shared_ptr<Loop>& loop,
  * completes, and errors are forwarded to the loop.  This is a convenience
  * wrapper.
  *
- * Either node or service may be null (`Twine::createNull()`) but not both.
+ * Either node or service may be empty but not both.
  *
  * @param loop Event loop
  * @param callback Callback function to call when resolution completes
@@ -90,7 +89,7 @@ inline void GetAddrInfo(const std::shared_ptr<Loop>& loop,
  *              type constraints.
  */
 void GetAddrInfo(Loop& loop, std::function<void(const addrinfo&)> callback,
-                 const Twine& node, const Twine& service = Twine::createNull(),
+                 std::string_view node, std::string_view service = {},
                  const addrinfo* hints = nullptr);
 
 /**
@@ -98,7 +97,7 @@ void GetAddrInfo(Loop& loop, std::function<void(const addrinfo&)> callback,
  * completes, and errors are forwarded to the loop.  This is a convenience
  * wrapper.
  *
- * Either node or service may be null (`Twine::createNull()`) but not both.
+ * Either node or service may be empty but not both.
  *
  * @param loop Event loop
  * @param callback Callback function to call when resolution completes
@@ -109,8 +108,7 @@ void GetAddrInfo(Loop& loop, std::function<void(const addrinfo&)> callback,
  */
 inline void GetAddrInfo(const std::shared_ptr<Loop>& loop,
                         std::function<void(const addrinfo&)> callback,
-                        const Twine& node,
-                        const Twine& service = Twine::createNull(),
+                        std::string_view node, std::string_view service = {},
                         const addrinfo* hints = nullptr) {
   GetAddrInfo(*loop, callback, node, service, hints);
 }
diff --git a/wpiutil/src/main/native/include/wpi/uv/GetNameInfo.h b/wpiutil/src/main/native/include/wpi/uv/GetNameInfo.h
index c53618f9db..a014742af4 100644
--- a/wpiutil/src/main/native/include/wpi/uv/GetNameInfo.h
+++ b/wpiutil/src/main/native/include/wpi/uv/GetNameInfo.h
@@ -9,9 +9,9 @@
 
 #include <functional>
 #include <memory>
+#include <string_view>
 
 #include "wpi/Signal.h"
-#include "wpi/Twine.h"
 #include "wpi/uv/Request.h"
 
 namespace wpi::uv {
@@ -105,7 +105,7 @@ inline void GetNameInfo(const std::shared_ptr<Loop>& loop,
  * @param flags Optional flags to modify the behavior of `getnameinfo`.
  */
 void GetNameInfo4(Loop& loop, const std::shared_ptr<GetNameInfoReq>& req,
-                  const Twine& ip, unsigned int port, int flags = 0);
+                  std::string_view ip, unsigned int port, int flags = 0);
 
 /**
  * Asynchronous IPv4 getnameinfo(3).  HandleResolvedName() is called on the
@@ -120,7 +120,8 @@ void GetNameInfo4(Loop& loop, const std::shared_ptr<GetNameInfoReq>& req,
  */
 inline void GetNameInfo4(const std::shared_ptr<Loop>& loop,
                          const std::shared_ptr<GetNameInfoReq>& req,
-                         const Twine& ip, unsigned int port, int flags = 0) {
+                         std::string_view ip, unsigned int port,
+                         int flags = 0) {
   return GetNameInfo4(*loop, req, ip, port, flags);
 }
 
@@ -136,7 +137,7 @@ inline void GetNameInfo4(const std::shared_ptr<Loop>& loop,
  */
 void GetNameInfo4(Loop& loop,
                   std::function<void(const char*, const char*)> callback,
-                  const Twine& ip, unsigned int port, int flags = 0);
+                  std::string_view ip, unsigned int port, int flags = 0);
 
 /**
  * Asynchronous IPv4 getnameinfo(3).  The callback is called when the resolution
@@ -151,7 +152,8 @@ void GetNameInfo4(Loop& loop,
  */
 inline void GetNameInfo4(const std::shared_ptr<Loop>& loop,
                          std::function<void(const char*, const char*)> callback,
-                         const Twine& ip, unsigned int port, int flags = 0) {
+                         std::string_view ip, unsigned int port,
+                         int flags = 0) {
   return GetNameInfo4(*loop, callback, ip, port, flags);
 }
 
@@ -167,7 +169,7 @@ inline void GetNameInfo4(const std::shared_ptr<Loop>& loop,
  * @param flags Optional flags to modify the behavior of `getnameinfo`.
  */
 void GetNameInfo6(Loop& loop, const std::shared_ptr<GetNameInfoReq>& req,
-                  const Twine& ip, unsigned int port, int flags = 0);
+                  std::string_view ip, unsigned int port, int flags = 0);
 
 /**
  * Asynchronous IPv6 getnameinfo(3).  HandleResolvedName() is called on the
@@ -182,7 +184,8 @@ void GetNameInfo6(Loop& loop, const std::shared_ptr<GetNameInfoReq>& req,
  */
 inline void GetNameInfo6(const std::shared_ptr<Loop>& loop,
                          const std::shared_ptr<GetNameInfoReq>& req,
-                         const Twine& ip, unsigned int port, int flags = 0) {
+                         std::string_view ip, unsigned int port,
+                         int flags = 0) {
   GetNameInfo6(*loop, req, ip, port, flags);
 }
 
@@ -199,7 +202,7 @@ inline void GetNameInfo6(const std::shared_ptr<Loop>& loop,
  */
 void GetNameInfo6(Loop& loop,
                   std::function<void(const char*, const char*)> callback,
-                  const Twine& ip, unsigned int port, int flags = 0);
+                  std::string_view ip, unsigned int port, int flags = 0);
 
 /**
  * Asynchronous IPv6 getnameinfo(3).  The callback is called when the resolution
@@ -214,7 +217,8 @@ void GetNameInfo6(Loop& loop,
  */
 inline void GetNameInfo6(const std::shared_ptr<Loop>& loop,
                          std::function<void(const char*, const char*)> callback,
-                         const Twine& ip, unsigned int port, int flags = 0) {
+                         std::string_view ip, unsigned int port,
+                         int flags = 0) {
   return GetNameInfo6(*loop, callback, ip, port, flags);
 }
 
diff --git a/wpiutil/src/main/native/include/wpi/uv/Handle.h b/wpiutil/src/main/native/include/wpi/uv/Handle.h
index 973d0d2ab6..8dc02f2d80 100644
--- a/wpiutil/src/main/native/include/wpi/uv/Handle.h
+++ b/wpiutil/src/main/native/include/wpi/uv/Handle.h
@@ -10,10 +10,10 @@
 #include <cstdlib>
 #include <functional>
 #include <memory>
+#include <string_view>
 #include <utility>
 
 #include "wpi/Signal.h"
-#include "wpi/StringRef.h"
 #include "wpi/uv/Buffer.h"
 #include "wpi/uv/Error.h"
 #include "wpi/uv/Loop.h"
@@ -50,7 +50,7 @@ class Handle : public std::enable_shared_from_this<Handle> {
   /**
    * Get the name of the type of the handle.  E.g. "pipe" for pipe handles.
    */
-  StringRef GetTypeName() const noexcept {
+  std::string_view GetTypeName() const noexcept {
     return uv_handle_type_name(m_uv_handle->type);
   }
 
diff --git a/wpiutil/src/main/native/include/wpi/uv/Pipe.h b/wpiutil/src/main/native/include/wpi/uv/Pipe.h
index d8dfb3d2da..e223268f50 100644
--- a/wpiutil/src/main/native/include/wpi/uv/Pipe.h
+++ b/wpiutil/src/main/native/include/wpi/uv/Pipe.h
@@ -10,8 +10,8 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <string_view>
 
-#include "wpi/Twine.h"
 #include "wpi/uv/NetworkStream.h"
 
 namespace wpi::uv {
@@ -119,7 +119,7 @@ class Pipe final : public NetworkStreamImpl<Pipe, uv_pipe_t> {
    *
    * @param name File path (Unix) or name (Windows).
    */
-  void Bind(const Twine& name);
+  void Bind(std::string_view name);
 
   /**
    * Connect to the Unix domain socket or the named pipe.
@@ -135,7 +135,8 @@ class Pipe final : public NetworkStreamImpl<Pipe, uv_pipe_t> {
    * @param name File path (Unix) or name (Windows).
    * @param req connection request
    */
-  void Connect(const Twine& name, const std::shared_ptr<PipeConnectReq>& req);
+  void Connect(std::string_view name,
+               const std::shared_ptr<PipeConnectReq>& req);
 
   /**
    * Connect to the Unix domain socket or the named pipe.
@@ -149,7 +150,7 @@ class Pipe final : public NetworkStreamImpl<Pipe, uv_pipe_t> {
    * @param name File path (Unix) or name (Windows).
    * @param callback Callback function to call when connection established
    */
-  void Connect(const Twine& name, std::function<void()> callback);
+  void Connect(std::string_view name, std::function<void()> callback);
 
   /**
    * Get the name of the Unix domain socket or the named pipe.
diff --git a/wpiutil/src/main/native/include/wpi/uv/Process.h b/wpiutil/src/main/native/include/wpi/uv/Process.h
index 28310962a7..8e5ebc80d0 100644
--- a/wpiutil/src/main/native/include/wpi/uv/Process.h
+++ b/wpiutil/src/main/native/include/wpi/uv/Process.h
@@ -10,11 +10,11 @@
 #include <initializer_list>
 #include <memory>
 #include <string>
+#include <string_view>
 
 #include "wpi/ArrayRef.h"
 #include "wpi/Signal.h"
 #include "wpi/SmallVector.h"
-#include "wpi/Twine.h"
 #include "wpi/uv/Handle.h"
 
 namespace wpi::uv {
@@ -35,9 +35,9 @@ class Process final : public HandleImpl<Process, uv_process_t> {
   ~Process() noexcept override = default;
 
   /**
-   * Structure for Spawn() option temporaries.  This is a reference type
-   * similar to StringRef, so if this value is stored outside of a temporary,
-   * be careful about overwriting what it points to.
+   * Structure for Spawn() option temporaries.  This is a reference type, so if
+   * this value is stored outside of a temporary, be careful about overwriting
+   * what it points to.
    */
   struct Option {
     enum Type {
@@ -65,7 +65,7 @@ class Process final : public HandleImpl<Process, uv_process_t> {
       m_data.str = arg.data();
     }
 
-    /*implicit*/ Option(StringRef arg)  // NOLINT
+    /*implicit*/ Option(std::string_view arg)  // NOLINT
         : m_strData(arg) {
       m_data.str = m_strData.c_str();
     }
@@ -75,11 +75,6 @@ class Process final : public HandleImpl<Process, uv_process_t> {
       m_data.str = m_strData.c_str();
     }
 
-    /*implicit*/ Option(const Twine& arg)  // NOLINT
-        : m_strData(arg.str()) {
-      m_data.str = m_strData.c_str();
-    }
-
     explicit Option(Type type) : m_type(type) {}
 
     Type m_type = kArg;
@@ -105,9 +100,9 @@ class Process final : public HandleImpl<Process, uv_process_t> {
    * environment is used.
    * @param env environment variable
    */
-  static Option Env(const Twine& env) {
+  static Option Env(std::string_view env) {
     Option o(Option::kEnv);
-    o.m_strData = env.str();
+    o.m_strData = env;
     o.m_data.str = o.m_strData.c_str();
     return o;
   }
@@ -116,9 +111,9 @@ class Process final : public HandleImpl<Process, uv_process_t> {
    * Set the current working directory for the subprocess.
    * @param cwd current working directory
    */
-  static Option Cwd(const Twine& cwd) {
+  static Option Cwd(std::string_view cwd) {
     Option o(Option::kCwd);
-    o.m_strData = cwd.str();
+    o.m_strData = cwd;
     o.m_data.str = o.m_strData.c_str();
     return o;
   }
@@ -236,16 +231,17 @@ class Process final : public HandleImpl<Process, uv_process_t> {
    * @param file Path pointing to the program to be executed
    * @param options Process options
    */
-  static std::shared_ptr<Process> SpawnArray(Loop& loop, const Twine& file,
+  static std::shared_ptr<Process> SpawnArray(Loop& loop, std::string_view file,
                                              ArrayRef<Option> options);
 
   static std::shared_ptr<Process> SpawnArray(
-      Loop& loop, const Twine& file, std::initializer_list<Option> options) {
+      Loop& loop, std::string_view file,
+      std::initializer_list<Option> options) {
     return SpawnArray(loop, file, makeArrayRef(options.begin(), options.end()));
   }
 
   template <typename... Args>
-  static std::shared_ptr<Process> Spawn(Loop& loop, const Twine& file,
+  static std::shared_ptr<Process> Spawn(Loop& loop, std::string_view file,
                                         const Args&... options) {
     return SpawnArray(loop, file, {options...});
   }
@@ -264,20 +260,20 @@ class Process final : public HandleImpl<Process, uv_process_t> {
    * @param options Process options
    */
   static std::shared_ptr<Process> SpawnArray(const std::shared_ptr<Loop>& loop,
-                                             const Twine& file,
+                                             std::string_view file,
                                              ArrayRef<Option> options) {
     return SpawnArray(*loop, file, options);
   }
 
   static std::shared_ptr<Process> SpawnArray(
-      const std::shared_ptr<Loop>& loop, const Twine& file,
+      const std::shared_ptr<Loop>& loop, std::string_view file,
       std::initializer_list<Option> options) {
     return SpawnArray(*loop, file, options);
   }
 
   template <typename... Args>
   static std::shared_ptr<Process> Spawn(const std::shared_ptr<Loop>& loop,
-                                        const Twine& file,
+                                        std::string_view file,
                                         const Args&... options) {
     return SpawnArray(*loop, file, {options...});
   }
diff --git a/wpiutil/src/main/native/include/wpi/uv/Tcp.h b/wpiutil/src/main/native/include/wpi/uv/Tcp.h
index cd2d9a57d2..797abccb36 100644
--- a/wpiutil/src/main/native/include/wpi/uv/Tcp.h
+++ b/wpiutil/src/main/native/include/wpi/uv/Tcp.h
@@ -10,8 +10,8 @@
 #include <chrono>
 #include <functional>
 #include <memory>
+#include <string_view>
 
-#include "wpi/Twine.h"
 #include "wpi/uv/NetworkStream.h"
 
 namespace wpi::uv {
@@ -185,7 +185,7 @@ class Tcp final : public NetworkStreamImpl<Tcp, uv_tcp_t> {
    * @param port The port to which to bind.
    * @param flags Optional additional flags.
    */
-  void Bind(const Twine& ip, unsigned int port, unsigned int flags = 0);
+  void Bind(std::string_view ip, unsigned int port, unsigned int flags = 0);
 
   /**
    * Bind the handle to an IPv6 address and port.
@@ -201,7 +201,7 @@ class Tcp final : public NetworkStreamImpl<Tcp, uv_tcp_t> {
    * @param port The port to which to bind.
    * @param flags Optional additional flags.
    */
-  void Bind6(const Twine& ip, unsigned int port, unsigned int flags = 0);
+  void Bind6(std::string_view ip, unsigned int port, unsigned int flags = 0);
 
   /**
    * Get the current address to which the handle is bound.
@@ -281,7 +281,7 @@ class Tcp final : public NetworkStreamImpl<Tcp, uv_tcp_t> {
    * @param port The port to which to connect to.
    * @param req connection request
    */
-  void Connect(const Twine& ip, unsigned int port,
+  void Connect(std::string_view ip, unsigned int port,
                const std::shared_ptr<TcpConnectReq>& req);
 
   /**
@@ -298,7 +298,7 @@ class Tcp final : public NetworkStreamImpl<Tcp, uv_tcp_t> {
    * @param port The port to which to connect to.
    * @param callback Callback function to call when connection established
    */
-  void Connect(const Twine& ip, unsigned int port,
+  void Connect(std::string_view ip, unsigned int port,
                std::function<void()> callback);
 
   /**
@@ -317,7 +317,7 @@ class Tcp final : public NetworkStreamImpl<Tcp, uv_tcp_t> {
    * @param port The port to which to connect to.
    * @param req connection request
    */
-  void Connect6(const Twine& ip, unsigned int port,
+  void Connect6(std::string_view ip, unsigned int port,
                 const std::shared_ptr<TcpConnectReq>& req);
 
   /**
@@ -334,7 +334,7 @@ class Tcp final : public NetworkStreamImpl<Tcp, uv_tcp_t> {
    * @param port The port to which to connect to.
    * @param callback Callback function to call when connection established
    */
-  void Connect6(const Twine& ip, unsigned int port,
+  void Connect6(std::string_view ip, unsigned int port,
                 std::function<void()> callback);
 
  private:
diff --git a/wpiutil/src/main/native/include/wpi/uv/Udp.h b/wpiutil/src/main/native/include/wpi/uv/Udp.h
index 7401f23f61..f4199bc8dd 100644
--- a/wpiutil/src/main/native/include/wpi/uv/Udp.h
+++ b/wpiutil/src/main/native/include/wpi/uv/Udp.h
@@ -9,10 +9,10 @@
 
 #include <functional>
 #include <memory>
+#include <string_view>
 
 #include "wpi/ArrayRef.h"
 #include "wpi/Signal.h"
-#include "wpi/Twine.h"
 #include "wpi/uv/Handle.h"
 #include "wpi/uv/Request.h"
 
@@ -100,7 +100,7 @@ class Udp final : public HandleImpl<Udp, uv_udp_t> {
    * @param port The port to which to bind.
    * @param flags Optional additional flags.
    */
-  void Bind(const Twine& ip, unsigned int port, unsigned int flags = 0);
+  void Bind(std::string_view ip, unsigned int port, unsigned int flags = 0);
 
   /**
    * Bind the handle to an IPv6 address and port.
@@ -109,7 +109,7 @@ class Udp final : public HandleImpl<Udp, uv_udp_t> {
    * @param port The port to which to bind.
    * @param flags Optional additional flags.
    */
-  void Bind6(const Twine& ip, unsigned int port, unsigned int flags = 0);
+  void Bind6(std::string_view ip, unsigned int port, unsigned int flags = 0);
 
   /**
    * Associate the handle to a remote address and port, so every message sent
@@ -136,7 +136,7 @@ class Udp final : public HandleImpl<Udp, uv_udp_t> {
    * @param ip The address to which to bind.
    * @param port The port to which to bind.
    */
-  void Connect(const Twine& ip, unsigned int port);
+  void Connect(std::string_view ip, unsigned int port);
 
   /**
    * Associate the handle to an IPv6 address and port, so every message sent
@@ -146,7 +146,7 @@ class Udp final : public HandleImpl<Udp, uv_udp_t> {
    * @param port The port to which to bind.
    * @param flags Optional additional flags.
    */
-  void Connect6(const Twine& ip, unsigned int port);
+  void Connect6(std::string_view ip, unsigned int port);
 
   /**
    * Get the remote IP and port on connected UDP handles.
@@ -167,8 +167,8 @@ class Udp final : public HandleImpl<Udp, uv_udp_t> {
    * @param interfaceAddr Interface address
    * @param membership Should be UV_JOIN_GROUP or UV_LEAVE_GROUP
    */
-  void SetMembership(const Twine& multicastAddr, const Twine& interfaceAddr,
-                     uv_membership membership);
+  void SetMembership(std::string_view multicastAddr,
+                     std::string_view interfaceAddr, uv_membership membership);
 
   /**
    * Set IP multicast loop flag.  Makes multicast packets loop back to local
@@ -194,7 +194,7 @@ class Udp final : public HandleImpl<Udp, uv_udp_t> {
    *
    * @param interfaceAddr Interface address
    */
-  void SetMulticastInterface(const Twine& interfaceAddr);
+  void SetMulticastInterface(std::string_view interfaceAddr);
 
   /**
    * Set broadcast on or off.
diff --git a/wpiutil/src/main/native/include/wpi/uv/util.h b/wpiutil/src/main/native/include/wpi/uv/util.h
index 97f163010a..01dec0b41a 100644
--- a/wpiutil/src/main/native/include/wpi/uv/util.h
+++ b/wpiutil/src/main/native/include/wpi/uv/util.h
@@ -8,8 +8,7 @@
 #include <uv.h>
 
 #include <cstring>
-
-#include "wpi/Twine.h"
+#include <string_view>
 
 namespace wpi::uv {
 
@@ -116,7 +115,7 @@ int AddrToName(const in6_addr& addr, T* ip) {
  * @param addr Output binary structure
  * @return Error (same as `uv_ip4_addr()`).
  */
-int NameToAddr(const Twine& ip, unsigned int port, sockaddr_in* addr);
+int NameToAddr(std::string_view ip, unsigned int port, sockaddr_in* addr);
 
 /**
  * Convert a string containing an IPv6 address to a binary structure.
@@ -125,7 +124,7 @@ int NameToAddr(const Twine& ip, unsigned int port, sockaddr_in* addr);
  * @param addr Output binary structure
  * @return Error (same as `uv_ip6_addr()`).
  */
-int NameToAddr(const Twine& ip, unsigned int port, sockaddr_in6* addr);
+int NameToAddr(std::string_view ip, unsigned int port, sockaddr_in6* addr);
 
 /**
  * Convert a string containing an IPv4 address to binary format.
@@ -133,7 +132,7 @@ int NameToAddr(const Twine& ip, unsigned int port, sockaddr_in6* addr);
  * @param addr Output binary
  * @return Error (same as `uv_inet_pton()`).
  */
-int NameToAddr(const Twine& ip, in_addr* addr);
+int NameToAddr(std::string_view ip, in_addr* addr);
 
 /**
  * Convert a string containing an IPv6 address to binary format.
@@ -141,7 +140,7 @@ int NameToAddr(const Twine& ip, in_addr* addr);
  * @param addr Output binary
  * @return Error (same as `uv_inet_pton()`).
  */
-int NameToAddr(const Twine& ip, in6_addr* addr);
+int NameToAddr(std::string_view ip, in6_addr* addr);
 
 }  // namespace wpi::uv
 
diff --git a/wpiutil/src/main/native/unix/Demangle.cpp b/wpiutil/src/main/native/unix/Demangle.cpp
index 14382429c9..69404ed792 100644
--- a/wpiutil/src/main/native/unix/Demangle.cpp
+++ b/wpiutil/src/main/native/unix/Demangle.cpp
@@ -12,14 +12,12 @@
 
 namespace wpi {
 
-std::string Demangle(const Twine& mangledSymbol) {
-  SmallString<128> buf;
+std::string Demangle(std::string_view mangledSymbol) {
+  SmallString<128> buf{mangledSymbol};
   size_t length;
   int32_t status;
 
-  char* symbol =
-      abi::__cxa_demangle(mangledSymbol.toNullTerminatedStringRef(buf).data(),
-                          nullptr, &length, &status);
+  char* symbol = abi::__cxa_demangle(buf.c_str(), nullptr, &length, &status);
   if (status == 0) {
     std::string rv{symbol};
     std::free(symbol);
@@ -27,7 +25,7 @@ std::string Demangle(const Twine& mangledSymbol) {
   }
 
   // If everything else failed, just return the mangled symbol
-  return mangledSymbol.str();
+  return std::string{mangledSymbol};
 }
 
 }  // namespace wpi
diff --git a/wpiutil/src/main/native/unix/StackTrace.cpp b/wpiutil/src/main/native/unix/StackTrace.cpp
index 3b14925e56..598c9da099 100644
--- a/wpiutil/src/main/native/unix/StackTrace.cpp
+++ b/wpiutil/src/main/native/unix/StackTrace.cpp
@@ -8,7 +8,7 @@
 
 #include "wpi/Demangle.h"
 #include "wpi/SmallString.h"
-#include "wpi/StringRef.h"
+#include "wpi/StringExtras.h"
 #include "wpi/raw_ostream.h"
 
 namespace wpi {
@@ -24,19 +24,18 @@ std::string GetStackTrace(int offset) {
     // Only print recursive functions once in a row.
     if (i == 0 || stackTrace[i] != stackTrace[i - 1]) {
       // extract just function name from "pathToExe(functionName+offset)"
-      StringRef sym{mangledSymbols[i]};
-      sym = sym.split('(').second;
-      StringRef offset;
-      std::tie(sym, offset) = sym.split('+');
-      StringRef addr;
-      std::tie(offset, addr) = offset.split(')');
+      std::string_view sym = split(mangledSymbols[i], '(').second;
+      std::string_view offset;
+      std::tie(sym, offset) = split(sym, '+');
+      std::string_view addr;
+      std::tie(offset, addr) = split(offset, ')');
       trace << "\tat " << Demangle(sym) << " + " << offset << addr << "\n";
     }
   }
 
   std::free(mangledSymbols);
 
-  return trace.str();
+  return std::string{trace.str()};
 }
 
 }  // namespace wpi
diff --git a/wpiutil/src/main/native/windows/Demangle.cpp b/wpiutil/src/main/native/windows/Demangle.cpp
index dc55c70bcf..1b0a8a7363 100644
--- a/wpiutil/src/main/native/windows/Demangle.cpp
+++ b/wpiutil/src/main/native/windows/Demangle.cpp
@@ -15,16 +15,15 @@
 
 namespace wpi {
 
-std::string Demangle(const Twine& mangledSymbol) {
+std::string Demangle(std::string_view mangledSymbol) {
   static wpi::mutex m;
   std::scoped_lock lock(m);
-  SmallString<128> buf;
+  SmallString<128> buf{mangledSymbol};
   char buffer[256];
-  DWORD sz =
-      UnDecorateSymbolName(mangledSymbol.toNullTerminatedStringRef(buf).data(),
-                           buffer, sizeof(buffer), UNDNAME_COMPLETE);
+  DWORD sz = UnDecorateSymbolName(buf.c_str(), buffer, sizeof(buffer),
+                                  UNDNAME_COMPLETE);
   if (sz == 0)
-    return mangledSymbol.str();
+    return std::string{mangledSymbol};
   return std::string(buffer, sz);
 }
 
diff --git a/wpiutil/src/netconsoleServer/native/cpp/main.cpp b/wpiutil/src/netconsoleServer/native/cpp/main.cpp
index 383e01536b..fdd3be32a8 100644
--- a/wpiutil/src/netconsoleServer/native/cpp/main.cpp
+++ b/wpiutil/src/netconsoleServer/native/cpp/main.cpp
@@ -8,9 +8,12 @@
 #include <pty.h>
 #endif
 
+#include <cstdio>
+
+#include "fmt/format.h"
 #include "wpi/MathExtras.h"
 #include "wpi/SmallVector.h"
-#include "wpi/raw_ostream.h"
+#include "wpi/StringExtras.h"
 #include "wpi/raw_uv_ostream.h"
 #include "wpi/timestamp.h"
 #include "wpi/uv/Loop.h"
@@ -30,9 +33,9 @@ static bool NewlineBuffer(std::string& rem, uv::Buffer& buf, size_t len,
                           wpi::SmallVectorImpl<uv::Buffer>& bufs, bool tcp,
                           uint16_t tcpSeq) {
   // scan for last newline
-  wpi::StringRef str(buf.base, len);
+  std::string_view str(buf.base, len);
   size_t idx = str.rfind('\n');
-  if (idx == wpi::StringRef::npos) {
+  if (idx == std::string_view::npos) {
     // no newline yet, just keep appending to remainder
     rem += str;
     return false;
@@ -40,7 +43,7 @@ static bool NewlineBuffer(std::string& rem, uv::Buffer& buf, size_t len,
 
   // build output
   wpi::raw_uv_ostream out(bufs, 4096);
-  wpi::StringRef toCopy = str.slice(0, idx + 1);
+  std::string_view toCopy = wpi::slice(str, 0, idx + 1);
   if (tcp) {
     // Header is 2 byte len, 1 byte type, 4 byte timestamp, 2 byte sequence num
     uint32_t ts = wpi::FloatToBits((wpi::Now() - startTime) * 1.0e-6);
@@ -59,7 +62,7 @@ static bool NewlineBuffer(std::string& rem, uv::Buffer& buf, size_t len,
   out << rem << toCopy;
 
   // reset remainder
-  rem = str.slice(idx + 1, wpi::StringRef::npos);
+  rem = wpi::slice(str, idx + 1, std::string_view::npos);
   return true;
 }
 
@@ -136,24 +139,26 @@ int main(int argc, char* argv[]) {
   bool err = false;
 
   while (programArgc < argc && argv[programArgc][0] == '-') {
-    if (wpi::StringRef(argv[programArgc]) == "-u") {
+    if (std::string_view(argv[programArgc]) == "-u") {
       useUdp = true;
-    } else if (wpi::StringRef(argv[programArgc]) == "-b") {
+    } else if (std::string_view(argv[programArgc]) == "-b") {
       useUdp = true;
       broadcastUdp = true;
     } else {
-      wpi::errs() << "unrecognized command line option " << argv[programArgc]
-                  << '\n';
+      fmt::print(stderr, "unrecognized command line option {}\n",
+                 argv[programArgc]);
       err = true;
     }
     ++programArgc;
   }
 
   if (err || (argc - programArgc) < 1) {
-    wpi::errs()
-        << argv[0] << " [-ub] program [arguments ...]\n"
-        << "  -u  send udp to localhost port 6666 instead of using tcp\n"
-        << "  -b  broadcast udp to port 6666 instead of using tcp\n";
+    std::fputs(argv[0], stderr);
+    std::fputs(
+        " [-ub] program [arguments ...]\n"
+        "  -u  send udp to localhost port 6666 instead of using tcp\n"
+        "  -b  broadcast udp to port 6666 instead of using tcp\n",
+        stderr);
     return EXIT_FAILURE;
   }
 
@@ -161,7 +166,7 @@ int main(int argc, char* argv[]) {
 
   auto loop = uv::Loop::Create();
   loop->error.connect(
-      [](uv::Error err) { wpi::errs() << "uv ERROR: " << err.str() << '\n'; });
+      [](uv::Error err) { fmt::print(stderr, "uv ERROR: {}\n", err.str()); });
 
   // create pipes to communicate with child
   auto stdinPipe = uv::Pipe::Create(loop);
@@ -249,7 +254,7 @@ int main(int argc, char* argv[]) {
 
   auto proc = uv::Process::SpawnArray(loop, argv[programArgc], options);
   if (!proc) {
-    wpi::errs() << "could not start subprocess\n";
+    std::fputs("could not start subprocess\n", stderr);
     return EXIT_FAILURE;
   }
   proc->exited.connect([](int64_t status, int) { std::exit(status); });
diff --git a/wpiutil/src/netconsoleTee/native/cpp/main.cpp b/wpiutil/src/netconsoleTee/native/cpp/main.cpp
index 100e9e59e9..7053d9fc10 100644
--- a/wpiutil/src/netconsoleTee/native/cpp/main.cpp
+++ b/wpiutil/src/netconsoleTee/native/cpp/main.cpp
@@ -2,9 +2,12 @@
 // Open Source Software; you can modify and/or share it under the terms of
 // the WPILib BSD license file in the root directory of this project.
 
+#include <cstdio>
+
+#include "fmt/format.h"
 #include "wpi/MathExtras.h"
 #include "wpi/SmallVector.h"
-#include "wpi/raw_ostream.h"
+#include "wpi/StringExtras.h"
 #include "wpi/raw_uv_ostream.h"
 #include "wpi/timestamp.h"
 #include "wpi/uv/Loop.h"
@@ -21,9 +24,9 @@ static bool NewlineBuffer(std::string& rem, uv::Buffer& buf, size_t len,
                           wpi::SmallVectorImpl<uv::Buffer>& bufs, bool tcp,
                           uint16_t tcpSeq) {
   // scan for last newline
-  wpi::StringRef str(buf.base, len);
+  std::string_view str(buf.base, len);
   size_t idx = str.rfind('\n');
-  if (idx == wpi::StringRef::npos) {
+  if (idx == std::string_view::npos) {
     // no newline yet, just keep appending to remainder
     rem += str;
     return false;
@@ -31,7 +34,7 @@ static bool NewlineBuffer(std::string& rem, uv::Buffer& buf, size_t len,
 
   // build output
   wpi::raw_uv_ostream out(bufs, 4096);
-  wpi::StringRef toCopy = str.slice(0, idx + 1);
+  std::string_view toCopy = wpi::slice(str, 0, idx + 1);
   if (tcp) {
     // Header is 2 byte len, 1 byte type, 4 byte timestamp, 2 byte sequence num
     uint32_t ts = wpi::FloatToBits((wpi::Now() - startTime) * 1.0e-6);
@@ -50,7 +53,7 @@ static bool NewlineBuffer(std::string& rem, uv::Buffer& buf, size_t len,
   out << rem << toCopy;
 
   // reset remainder
-  rem = str.slice(idx + 1, wpi::StringRef::npos);
+  rem = wpi::slice(str, idx + 1, std::string_view::npos);
   return true;
 }
 
@@ -128,37 +131,42 @@ int main(int argc, char* argv[]) {
   int port = -1;
 
   while (arg < argc && argv[arg][0] == '-') {
-    if (wpi::StringRef(argv[arg]) == "-u") {
+    if (std::string_view(argv[arg]) == "-u") {
       useUdp = true;
-    } else if (wpi::StringRef(argv[arg]) == "-b") {
+    } else if (std::string_view(argv[arg]) == "-b") {
       useUdp = true;
       broadcastUdp = true;
-    } else if (wpi::StringRef(argv[arg]) == "-p") {
+    } else if (std::string_view(argv[arg]) == "-p") {
       ++arg;
+      std::optional<int> portValue;
       if (arg >= argc || argv[arg][0] == '-' ||
-          wpi::StringRef(argv[arg]).getAsInteger(10, port)) {
-        wpi::errs() << "-p must be followed by port number\n";
+          !(portValue = wpi::parse_integer<int>(argv[arg], 10))) {
+        std::fputs("-p must be followed by port number\n", stderr);
         err = true;
+      } else if (portValue) {
+        port = portValue.value();
       }
     } else {
-      wpi::errs() << "unrecognized command line option " << argv[arg] << '\n';
+      fmt::print(stderr, "unrecognized command line option {}\n", argv[arg]);
       err = true;
     }
     ++arg;
   }
 
   if (err) {
-    wpi::errs()
-        << argv[0] << " [-ub] [-p PORT]\n"
-        << "  -u       send udp to localhost port 6666 instead of using tcp\n"
-        << "  -b       broadcast udp to port 6666 instead of using tcp\n"
-        << "  -p PORT  use port PORT instead of 6666 (udp) or 1740 (tcp)\n";
+    std::fputs(argv[0], stderr);
+    std::fputs(
+        " [-ub] [-p PORT]\n"
+        "  -u       send udp to localhost port 6666 instead of using tcp\n"
+        "  -b       broadcast udp to port 6666 instead of using tcp\n"
+        "  -p PORT  use port PORT instead of 6666 (udp) or 1740 (tcp)\n",
+        stderr);
     return EXIT_FAILURE;
   }
 
   auto loop = uv::Loop::Create();
   loop->error.connect(
-      [](uv::Error err) { wpi::errs() << "uv ERROR: " << err.str() << '\n'; });
+      [](uv::Error err) { fmt::print(stderr, "uv ERROR: {}\n", err.str()); });
 
   // create ttys
   auto stdinTty = uv::Tty::Create(loop, 0, true);
diff --git a/wpiutil/src/test/native/cpp/Base64Test.cpp b/wpiutil/src/test/native/cpp/Base64Test.cpp
index b7fd057db6..94de88cdf5 100644
--- a/wpiutil/src/test/native/cpp/Base64Test.cpp
+++ b/wpiutil/src/test/native/cpp/Base64Test.cpp
@@ -23,11 +23,11 @@ std::ostream& operator<<(std::ostream& os, const Base64TestParam& param) {
 
 class Base64Test : public ::testing::TestWithParam<Base64TestParam> {
  protected:
-  StringRef GetPlain() {
+  std::string_view GetPlain() {
     if (GetParam().plain_len < 0) {
-      return StringRef(GetParam().plain);
+      return GetParam().plain;
     } else {
-      return StringRef(GetParam().plain, GetParam().plain_len);
+      return std::string_view(GetParam().plain, GetParam().plain_len);
     }
   }
 };
@@ -51,7 +51,7 @@ TEST_P(Base64Test, EncodeSmallString) {
 
 TEST_P(Base64Test, DecodeStdString) {
   std::string s;
-  StringRef encoded = GetParam().encoded;
+  std::string_view encoded = GetParam().encoded;
   EXPECT_EQ(encoded.size(), Base64Decode(encoded, &s));
   ASSERT_EQ(GetPlain(), s);
 
@@ -62,9 +62,9 @@ TEST_P(Base64Test, DecodeStdString) {
 
 TEST_P(Base64Test, DecodeSmallString) {
   SmallString<128> buf;
-  StringRef encoded = GetParam().encoded;
+  std::string_view encoded = GetParam().encoded;
   size_t len;
-  StringRef plain = Base64Decode(encoded, &len, buf);
+  std::string_view plain = Base64Decode(encoded, &len, buf);
   EXPECT_EQ(encoded.size(), len);
   ASSERT_EQ(GetPlain(), plain);
 
diff --git a/wpiutil/src/test/native/cpp/HttpParserTest.cpp b/wpiutil/src/test/native/cpp/HttpParserTest.cpp
index 735177df1e..281abd07ce 100644
--- a/wpiutil/src/test/native/cpp/HttpParserTest.cpp
+++ b/wpiutil/src/test/native/cpp/HttpParserTest.cpp
@@ -11,7 +11,7 @@ namespace wpi {
 TEST(HttpParserTest, UrlMethodHeadersComplete) {
   HttpParser p{HttpParser::kRequest};
   int callbacks = 0;
-  p.url.connect([&](StringRef path) {
+  p.url.connect([&](std::string_view path) {
     ASSERT_EQ(path, "/foo/bar");
     ASSERT_EQ(p.GetUrl(), "/foo/bar");
     ++callbacks;
@@ -29,7 +29,7 @@ TEST(HttpParserTest, UrlMethodHeadersComplete) {
 TEST(HttpParserTest, UrlMethodHeader) {
   HttpParser p{HttpParser::kRequest};
   int callbacks = 0;
-  p.url.connect([&](StringRef path) {
+  p.url.connect([&](std::string_view path) {
     ASSERT_EQ(path, "/foo/bar");
     ASSERT_EQ(p.GetUrl(), "/foo/bar");
     ++callbacks;
@@ -49,7 +49,7 @@ TEST(HttpParserTest, UrlMethodHeader) {
 TEST(HttpParserTest, StatusHeadersComplete) {
   HttpParser p{HttpParser::kResponse};
   int callbacks = 0;
-  p.status.connect([&](StringRef status) {
+  p.status.connect([&](std::string_view status) {
     ASSERT_EQ(status, "OK");
     ASSERT_EQ(p.GetStatusCode(), 200u);
     ++callbacks;
@@ -66,7 +66,7 @@ TEST(HttpParserTest, StatusHeadersComplete) {
 TEST(HttpParserTest, StatusHeader) {
   HttpParser p{HttpParser::kResponse};
   int callbacks = 0;
-  p.status.connect([&](StringRef status) {
+  p.status.connect([&](std::string_view status) {
     ASSERT_EQ(status, "OK");
     ASSERT_EQ(p.GetStatusCode(), 200u);
     ++callbacks;
@@ -83,7 +83,7 @@ TEST(HttpParserTest, StatusHeader) {
 TEST(HttpParserTest, HeaderFieldComplete) {
   HttpParser p{HttpParser::kRequest};
   int callbacks = 0;
-  p.header.connect([&](StringRef name, StringRef value) {
+  p.header.connect([&](std::string_view name, std::string_view value) {
     ASSERT_EQ(name, "Foo");
     ASSERT_EQ(value, "Bar");
     ++callbacks;
@@ -106,7 +106,7 @@ TEST(HttpParserTest, HeaderFieldComplete) {
 TEST(HttpParserTest, HeaderFieldNext) {
   HttpParser p{HttpParser::kRequest};
   int callbacks = 0;
-  p.header.connect([&](StringRef name, StringRef value) {
+  p.header.connect([&](std::string_view name, std::string_view value) {
     ASSERT_EQ(name, "Foo");
     ASSERT_EQ(value, "Bar");
     ++callbacks;
diff --git a/wpiutil/src/test/native/cpp/HttpWebSocketServerConnectionTest.cpp b/wpiutil/src/test/native/cpp/HttpWebSocketServerConnectionTest.cpp
index c5fda6f922..0502950943 100644
--- a/wpiutil/src/test/native/cpp/HttpWebSocketServerConnectionTest.cpp
+++ b/wpiutil/src/test/native/cpp/HttpWebSocketServerConnectionTest.cpp
@@ -12,7 +12,7 @@ class HttpWebSocketServerConnectionTest
     : public HttpWebSocketServerConnection<HttpWebSocketServerConnectionTest> {
  public:
   HttpWebSocketServerConnectionTest(std::shared_ptr<uv::Stream> stream,
-                                    ArrayRef<StringRef> protocols)
+                                    ArrayRef<std::string_view> protocols)
       : HttpWebSocketServerConnection{stream, protocols} {}
 
   void ProcessRequest() override { ++gotRequest; }
diff --git a/wpiutil/src/test/native/cpp/WebSocketClientTest.cpp b/wpiutil/src/test/native/cpp/WebSocketClientTest.cpp
index 3dc6c97437..ceef954784 100644
--- a/wpiutil/src/test/native/cpp/WebSocketClientTest.cpp
+++ b/wpiutil/src/test/native/cpp/WebSocketClientTest.cpp
@@ -8,6 +8,7 @@
 #include "wpi/Base64.h"
 #include "wpi/HttpParser.h"
 #include "wpi/SmallString.h"
+#include "wpi/StringExtras.h"
 #include "wpi/raw_uv_ostream.h"
 #include "wpi/sha1.h"
 
@@ -17,9 +18,9 @@ class WebSocketClientTest : public WebSocketTest {
  public:
   WebSocketClientTest() {
     // Bare bones server
-    req.header.connect([this](StringRef name, StringRef value) {
+    req.header.connect([this](std::string_view name, std::string_view value) {
       // save key (required for valid response)
-      if (name.equals_lower("sec-websocket-key")) {
+      if (equals_lower(name, "sec-websocket-key")) {
         clientKey = value;
       }
     });
@@ -65,7 +66,7 @@ class WebSocketClientTest : public WebSocketTest {
       conn = serverPipe->Accept();
       conn->StartRead();
       conn->data.connect([this](uv::Buffer& buf, size_t size) {
-        StringRef data{buf.base, size};
+        std::string_view data{buf.base, size};
         if (!serverHeadersDone) {
           data = req.Execute(data);
           if (req.HasError()) {
@@ -76,7 +77,7 @@ class WebSocketClientTest : public WebSocketTest {
             return;
           }
         }
-        wireData.insert(wireData.end(), data.bytes_begin(), data.bytes_end());
+        wireData.insert(wireData.end(), data.begin(), data.end());
       });
       conn->end.connect([this] { Finish(); });
     });
@@ -97,13 +98,13 @@ TEST_F(WebSocketClientTest, Open) {
 
   clientPipe->Connect(pipeName, [&] {
     auto ws = WebSocket::CreateClient(*clientPipe, "/test", pipeName);
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       Finish();
       if (code != 1005 && code != 1006) {
         FAIL() << "Code: " << code << " Reason: " << reason;
       }
     });
-    ws->open.connect([&](StringRef protocol) {
+    ws->open.connect([&](std::string_view protocol) {
       ++gotOpen;
       Finish();
       ASSERT_TRUE(protocol.empty());
@@ -125,12 +126,12 @@ TEST_F(WebSocketClientTest, BadAccept) {
 
   clientPipe->Connect(pipeName, [&] {
     auto ws = WebSocket::CreateClient(*clientPipe, "/test", pipeName);
-    ws->closed.connect([&](uint16_t code, StringRef msg) {
+    ws->closed.connect([&](uint16_t code, std::string_view msg) {
       Finish();
       ++gotClosed;
       ASSERT_EQ(code, 1002) << "Message: " << msg;
     });
-    ws->open.connect([&](StringRef protocol) {
+    ws->open.connect([&](std::string_view protocol) {
       Finish();
       FAIL() << "Got open";
     });
@@ -152,13 +153,13 @@ TEST_F(WebSocketClientTest, ProtocolGood) {
   clientPipe->Connect(pipeName, [&] {
     auto ws = WebSocket::CreateClient(*clientPipe, "/test", pipeName,
                                       {"myProtocol", "myProtocol2"});
-    ws->closed.connect([&](uint16_t code, StringRef msg) {
+    ws->closed.connect([&](uint16_t code, std::string_view msg) {
       Finish();
       if (code != 1005 && code != 1006) {
         FAIL() << "Code: " << code << "Message: " << msg;
       }
     });
-    ws->open.connect([&](StringRef protocol) {
+    ws->open.connect([&](std::string_view protocol) {
       ++gotOpen;
       Finish();
       ASSERT_EQ(protocol, "myProtocol");
@@ -180,12 +181,12 @@ TEST_F(WebSocketClientTest, ProtocolRespNotReq) {
 
   clientPipe->Connect(pipeName, [&] {
     auto ws = WebSocket::CreateClient(*clientPipe, "/test", pipeName);
-    ws->closed.connect([&](uint16_t code, StringRef msg) {
+    ws->closed.connect([&](uint16_t code, std::string_view msg) {
       Finish();
       ++gotClosed;
       ASSERT_EQ(code, 1003) << "Message: " << msg;
     });
-    ws->open.connect([&](StringRef protocol) {
+    ws->open.connect([&](std::string_view protocol) {
       Finish();
       FAIL() << "Got open";
     });
@@ -204,13 +205,13 @@ TEST_F(WebSocketClientTest, ProtocolReqNotResp) {
 
   clientPipe->Connect(pipeName, [&] {
     auto ws = WebSocket::CreateClient(*clientPipe, "/test", pipeName,
-                                      StringRef{"myProtocol"});
-    ws->closed.connect([&](uint16_t code, StringRef msg) {
+                                      std::string_view{"myProtocol"});
+    ws->closed.connect([&](uint16_t code, std::string_view msg) {
       Finish();
       ++gotClosed;
       ASSERT_EQ(code, 1002) << "Message: " << msg;
     });
-    ws->open.connect([&](StringRef protocol) {
+    ws->open.connect([&](std::string_view protocol) {
       Finish();
       FAIL() << "Got open";
     });
@@ -252,7 +253,7 @@ TEST_P(WebSocketClientDataTest, SendBinary) {
   int gotCallback = 0;
   std::vector<uint8_t> data(GetParam(), 0x03u);
   setupWebSocket = [&] {
-    ws->open.connect([&](StringRef) {
+    ws->open.connect([&](std::string_view) {
       ws->SendBinary(uv::Buffer(data), [&](auto bufs, uv::Error) {
         ++gotCallback;
         ws->Terminate();
@@ -300,11 +301,11 @@ TEST_P(WebSocketClientDataTest, ReceiveMasked) {
   int gotCallback = 0;
   std::vector<uint8_t> data(GetParam(), ' ');
   setupWebSocket = [&] {
-    ws->text.connect([&](StringRef, bool) {
+    ws->text.connect([&](std::string_view, bool) {
       ws->Terminate();
       FAIL() << "Should not have gotten masked message";
     });
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotCallback;
       ASSERT_EQ(code, 1002) << "reason: " << reason;
     });
diff --git a/wpiutil/src/test/native/cpp/WebSocketIntegrationTest.cpp b/wpiutil/src/test/native/cpp/WebSocketIntegrationTest.cpp
index abd3f83876..54112c286c 100644
--- a/wpiutil/src/test/native/cpp/WebSocketIntegrationTest.cpp
+++ b/wpiutil/src/test/native/cpp/WebSocketIntegrationTest.cpp
@@ -19,7 +19,7 @@ TEST_F(WebSocketIntegrationTest, Open) {
   serverPipe->Listen([&]() {
     auto conn = serverPipe->Accept();
     auto server = WebSocketServer::Create(*conn);
-    server->connected.connect([&](StringRef url, WebSocket&) {
+    server->connected.connect([&](std::string_view url, WebSocket&) {
       ++gotServerOpen;
       ASSERT_EQ(url, "/test");
     });
@@ -27,13 +27,13 @@ TEST_F(WebSocketIntegrationTest, Open) {
 
   clientPipe->Connect(pipeName, [&] {
     auto ws = WebSocket::CreateClient(*clientPipe, "/test", pipeName);
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       Finish();
       if (code != 1005 && code != 1006) {
         FAIL() << "Code: " << code << " Reason: " << reason;
       }
     });
-    ws->open.connect([&, s = ws.get()](StringRef) {
+    ws->open.connect([&, s = ws.get()](std::string_view) {
       ++gotClientOpen;
       s->Close();
     });
@@ -52,7 +52,7 @@ TEST_F(WebSocketIntegrationTest, Protocol) {
   serverPipe->Listen([&]() {
     auto conn = serverPipe->Accept();
     auto server = WebSocketServer::Create(*conn, {"proto1", "proto2"});
-    server->connected.connect([&](StringRef, WebSocket& ws) {
+    server->connected.connect([&](std::string_view, WebSocket& ws) {
       ++gotServerOpen;
       ASSERT_EQ(ws.GetProtocol(), "proto1");
     });
@@ -61,13 +61,13 @@ TEST_F(WebSocketIntegrationTest, Protocol) {
   clientPipe->Connect(pipeName, [&] {
     auto ws =
         WebSocket::CreateClient(*clientPipe, "/test", pipeName, {"proto1"});
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       Finish();
       if (code != 1005 && code != 1006) {
         FAIL() << "Code: " << code << " Reason: " << reason;
       }
     });
-    ws->open.connect([&, s = ws.get()](StringRef protocol) {
+    ws->open.connect([&, s = ws.get()](std::string_view protocol) {
       ++gotClientOpen;
       s->Close();
       ASSERT_EQ(protocol, "proto1");
@@ -86,7 +86,7 @@ TEST_F(WebSocketIntegrationTest, ServerSendBinary) {
   serverPipe->Listen([&]() {
     auto conn = serverPipe->Accept();
     auto server = WebSocketServer::Create(*conn);
-    server->connected.connect([&](StringRef, WebSocket& ws) {
+    server->connected.connect([&](std::string_view, WebSocket& ws) {
       ws.SendBinary(uv::Buffer{"\x03\x04", 2}, [&](auto, uv::Error) {});
       ws.Close();
     });
@@ -94,7 +94,7 @@ TEST_F(WebSocketIntegrationTest, ServerSendBinary) {
 
   clientPipe->Connect(pipeName, [&] {
     auto ws = WebSocket::CreateClient(*clientPipe, "/test", pipeName);
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       Finish();
       if (code != 1005 && code != 1006) {
         FAIL() << "Code: " << code << " Reason: " << reason;
@@ -119,8 +119,8 @@ TEST_F(WebSocketIntegrationTest, ClientSendText) {
   serverPipe->Listen([&]() {
     auto conn = serverPipe->Accept();
     auto server = WebSocketServer::Create(*conn);
-    server->connected.connect([&](StringRef, WebSocket& ws) {
-      ws.text.connect([&](StringRef data, bool) {
+    server->connected.connect([&](std::string_view, WebSocket& ws) {
+      ws.text.connect([&](std::string_view data, bool) {
         ++gotData;
         ASSERT_EQ(data, "hello");
       });
@@ -129,13 +129,13 @@ TEST_F(WebSocketIntegrationTest, ClientSendText) {
 
   clientPipe->Connect(pipeName, [&] {
     auto ws = WebSocket::CreateClient(*clientPipe, "/test", pipeName);
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       Finish();
       if (code != 1005 && code != 1006) {
         FAIL() << "Code: " << code << " Reason: " << reason;
       }
     });
-    ws->open.connect([&, s = ws.get()](StringRef) {
+    ws->open.connect([&, s = ws.get()](std::string_view) {
       s->SendText(uv::Buffer{"hello"}, [&](auto, uv::Error) {});
       s->Close();
     });
diff --git a/wpiutil/src/test/native/cpp/WebSocketServerTest.cpp b/wpiutil/src/test/native/cpp/WebSocketServerTest.cpp
index d3d7531d46..cd9dbba957 100644
--- a/wpiutil/src/test/native/cpp/WebSocketServerTest.cpp
+++ b/wpiutil/src/test/native/cpp/WebSocketServerTest.cpp
@@ -28,7 +28,7 @@ class WebSocketServerTest : public WebSocketTest {
     clientPipe->Connect(pipeName, [this]() {
       clientPipe->StartRead();
       clientPipe->data.connect([this](uv::Buffer& buf, size_t size) {
-        StringRef data{buf.base, size};
+        std::string_view data{buf.base, size};
         if (!headersDone) {
           data = resp.Execute(data);
           if (resp.HasError()) {
@@ -40,7 +40,7 @@ class WebSocketServerTest : public WebSocketTest {
             return;
           }
         }
-        wireData.insert(wireData.end(), data.bytes_begin(), data.bytes_end());
+        wireData.insert(wireData.end(), data.begin(), data.end());
         if (handleData) {
           handleData(data);
         }
@@ -50,7 +50,7 @@ class WebSocketServerTest : public WebSocketTest {
   }
 
   std::function<void()> setupWebSocket;
-  std::function<void(StringRef)> handleData;
+  std::function<void(std::string_view)> handleData;
   std::vector<uint8_t> wireData;
   std::shared_ptr<WebSocket> ws;
   HttpParser resp{HttpParser::kResponse};
@@ -64,8 +64,8 @@ class WebSocketServerTest : public WebSocketTest {
 TEST_F(WebSocketServerTest, Terminate) {
   int gotClosed = 0;
   setupWebSocket = [&] {
-    ws->open.connect([&](StringRef) { ws->Terminate(); });
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->open.connect([&](std::string_view) { ws->Terminate(); });
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotClosed;
       ASSERT_EQ(code, 1006) << "reason: " << reason;
     });
@@ -80,8 +80,8 @@ TEST_F(WebSocketServerTest, Terminate) {
 TEST_F(WebSocketServerTest, TerminateCode) {
   int gotClosed = 0;
   setupWebSocket = [&] {
-    ws->open.connect([&](StringRef) { ws->Terminate(1000); });
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->open.connect([&](std::string_view) { ws->Terminate(1000); });
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotClosed;
       ASSERT_EQ(code, 1000) << "reason: " << reason;
     });
@@ -96,8 +96,8 @@ TEST_F(WebSocketServerTest, TerminateCode) {
 TEST_F(WebSocketServerTest, TerminateReason) {
   int gotClosed = 0;
   setupWebSocket = [&] {
-    ws->open.connect([&](StringRef) { ws->Terminate(1000, "reason"); });
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->open.connect([&](std::string_view) { ws->Terminate(1000, "reason"); });
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotClosed;
       ASSERT_EQ(code, 1000);
       ASSERT_EQ(reason, "reason");
@@ -117,15 +117,15 @@ TEST_F(WebSocketServerTest, TerminateReason) {
 TEST_F(WebSocketServerTest, CloseBasic) {
   int gotClosed = 0;
   setupWebSocket = [&] {
-    ws->open.connect([&](StringRef) { ws->Close(); });
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->open.connect([&](std::string_view) { ws->Close(); });
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotClosed;
       ASSERT_EQ(code, 1005) << "reason: " << reason;
     });
   };
   // need to respond with close for server to finish shutdown
   auto message = BuildMessage(0x08, true, true, {});
-  handleData = [&](StringRef) {
+  handleData = [&](std::string_view) {
     clientPipe->Write(uv::Buffer(message), [&](auto bufs, uv::Error) {});
   };
 
@@ -139,8 +139,8 @@ TEST_F(WebSocketServerTest, CloseBasic) {
 TEST_F(WebSocketServerTest, CloseCode) {
   int gotClosed = 0;
   setupWebSocket = [&] {
-    ws->open.connect([&](StringRef) { ws->Close(1000); });
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->open.connect([&](std::string_view) { ws->Close(1000); });
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotClosed;
       ASSERT_EQ(code, 1000) << "reason: " << reason;
     });
@@ -148,7 +148,7 @@ TEST_F(WebSocketServerTest, CloseCode) {
   // need to respond with close for server to finish shutdown
   const uint8_t contents[] = {0x03u, 0xe8u};
   auto message = BuildMessage(0x08, true, true, contents);
-  handleData = [&](StringRef) {
+  handleData = [&](std::string_view) {
     clientPipe->Write(uv::Buffer(message), [&](auto bufs, uv::Error) {});
   };
 
@@ -162,8 +162,8 @@ TEST_F(WebSocketServerTest, CloseCode) {
 TEST_F(WebSocketServerTest, CloseReason) {
   int gotClosed = 0;
   setupWebSocket = [&] {
-    ws->open.connect([&](StringRef) { ws->Close(1000, "hangup"); });
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->open.connect([&](std::string_view) { ws->Close(1000, "hangup"); });
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotClosed;
       ASSERT_EQ(code, 1000);
       ASSERT_EQ(reason, "hangup");
@@ -172,7 +172,7 @@ TEST_F(WebSocketServerTest, CloseReason) {
   // need to respond with close for server to finish shutdown
   const uint8_t contents[] = {0x03u, 0xe8u, 'h', 'a', 'n', 'g', 'u', 'p'};
   auto message = BuildMessage(0x08, true, true, contents);
-  handleData = [&](StringRef) {
+  handleData = [&](std::string_view) {
     clientPipe->Write(uv::Buffer(message), [&](auto bufs, uv::Error) {});
   };
 
@@ -190,7 +190,7 @@ TEST_F(WebSocketServerTest, CloseReason) {
 TEST_F(WebSocketServerTest, ReceiveCloseBasic) {
   int gotClosed = 0;
   setupWebSocket = [&] {
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotClosed;
       ASSERT_EQ(code, 1005) << "reason: " << reason;
     });
@@ -211,7 +211,7 @@ TEST_F(WebSocketServerTest, ReceiveCloseBasic) {
 TEST_F(WebSocketServerTest, ReceiveCloseCode) {
   int gotClosed = 0;
   setupWebSocket = [&] {
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotClosed;
       ASSERT_EQ(code, 1000) << "reason: " << reason;
     });
@@ -233,7 +233,7 @@ TEST_F(WebSocketServerTest, ReceiveCloseCode) {
 TEST_F(WebSocketServerTest, ReceiveCloseReason) {
   int gotClosed = 0;
   setupWebSocket = [&] {
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotClosed;
       ASSERT_EQ(code, 1000);
       ASSERT_EQ(reason, "hangup");
@@ -271,7 +271,7 @@ TEST_P(WebSocketServerBadOpcodeTest, Receive) {
   int gotCallback = 0;
   std::vector<uint8_t> data(4, 0x03);
   setupWebSocket = [&] {
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotCallback;
       ASSERT_EQ(code, 1002) << "reason: " << reason;
     });
@@ -302,7 +302,7 @@ TEST_P(WebSocketServerControlFrameTest, ReceiveFragment) {
   int gotCallback = 0;
   std::vector<uint8_t> data(4, 0x03);
   setupWebSocket = [&] {
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotCallback;
       ASSERT_EQ(code, 1002) << "reason: " << reason;
     });
@@ -329,7 +329,7 @@ TEST_F(WebSocketServerTest, ReceiveFragmentInvalidNoPrevFrame) {
   int gotCallback = 0;
   std::vector<uint8_t> data(4, 0x03);
   setupWebSocket = [&] {
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotCallback;
       ASSERT_EQ(code, 1002) << "reason: " << reason;
     });
@@ -349,7 +349,7 @@ TEST_F(WebSocketServerTest, ReceiveFragmentInvalidNoPrevFragment) {
   int gotCallback = 0;
   std::vector<uint8_t> data(4, 0x03);
   setupWebSocket = [&] {
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotCallback;
       ASSERT_EQ(code, 1002) << "reason: " << reason;
     });
@@ -370,7 +370,7 @@ TEST_F(WebSocketServerTest, ReceiveFragmentInvalidNoPrevFragment) {
 TEST_F(WebSocketServerTest, ReceiveFragmentInvalidIncomplete) {
   int gotCallback = 0;
   setupWebSocket = [&] {
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotCallback;
       ASSERT_EQ(code, 1002) << "reason: " << reason;
     });
@@ -488,7 +488,7 @@ TEST_F(WebSocketServerTest, ReceiveTooLarge) {
       ws->Terminate();
       FAIL() << "Should not have gotten unmasked message";
     });
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotCallback;
       ASSERT_EQ(code, 1009) << "reason: " << reason;
     });
@@ -513,7 +513,7 @@ TEST_F(WebSocketServerTest, ReceiveTooLargeFragmented) {
       ws->Terminate();
       FAIL() << "Should not have gotten unmasked message";
     });
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotCallback;
       ASSERT_EQ(code, 1009) << "reason: " << reason;
     });
@@ -544,7 +544,7 @@ TEST_P(WebSocketServerDataTest, SendText) {
   int gotCallback = 0;
   std::vector<uint8_t> data(GetParam(), ' ');
   setupWebSocket = [&] {
-    ws->open.connect([&](StringRef) {
+    ws->open.connect([&](std::string_view) {
       ws->SendText(uv::Buffer(data), [&](auto bufs, uv::Error) {
         ++gotCallback;
         ws->Terminate();
@@ -565,7 +565,7 @@ TEST_P(WebSocketServerDataTest, SendBinary) {
   int gotCallback = 0;
   std::vector<uint8_t> data(GetParam(), 0x03u);
   setupWebSocket = [&] {
-    ws->open.connect([&](StringRef) {
+    ws->open.connect([&](std::string_view) {
       ws->SendBinary(uv::Buffer(data), [&](auto bufs, uv::Error) {
         ++gotCallback;
         ws->Terminate();
@@ -586,7 +586,7 @@ TEST_P(WebSocketServerDataTest, SendPing) {
   int gotCallback = 0;
   std::vector<uint8_t> data(GetParam(), 0x03u);
   setupWebSocket = [&] {
-    ws->open.connect([&](StringRef) {
+    ws->open.connect([&](std::string_view) {
       ws->SendPing(uv::Buffer(data), [&](auto bufs, uv::Error) {
         ++gotCallback;
         ws->Terminate();
@@ -607,7 +607,7 @@ TEST_P(WebSocketServerDataTest, SendPong) {
   int gotCallback = 0;
   std::vector<uint8_t> data(GetParam(), 0x03u);
   setupWebSocket = [&] {
-    ws->open.connect([&](StringRef) {
+    ws->open.connect([&](std::string_view) {
       ws->SendPong(uv::Buffer(data), [&](auto bufs, uv::Error) {
         ++gotCallback;
         ws->Terminate();
@@ -628,12 +628,12 @@ TEST_P(WebSocketServerDataTest, ReceiveText) {
   int gotCallback = 0;
   std::vector<uint8_t> data(GetParam(), ' ');
   setupWebSocket = [&] {
-    ws->text.connect([&](StringRef inData, bool fin) {
+    ws->text.connect([&](std::string_view inData, bool fin) {
       ++gotCallback;
       ws->Terminate();
       ASSERT_TRUE(fin);
       std::vector<uint8_t> recvData;
-      recvData.insert(recvData.end(), inData.bytes_begin(), inData.bytes_end());
+      recvData.insert(recvData.end(), inData.begin(), inData.end());
       ASSERT_EQ(data, recvData);
     });
   };
@@ -719,11 +719,11 @@ TEST_P(WebSocketServerDataTest, ReceiveUnmasked) {
   int gotCallback = 0;
   std::vector<uint8_t> data(GetParam(), ' ');
   setupWebSocket = [&] {
-    ws->text.connect([&](StringRef, bool) {
+    ws->text.connect([&](std::string_view, bool) {
       ws->Terminate();
       FAIL() << "Should not have gotten unmasked message";
     });
-    ws->closed.connect([&](uint16_t code, StringRef reason) {
+    ws->closed.connect([&](uint16_t code, std::string_view reason) {
       ++gotCallback;
       ASSERT_EQ(code, 1002) << "reason: " << reason;
     });
diff --git a/wpiutil/src/test/native/cpp/WebSocketTest.cpp b/wpiutil/src/test/native/cpp/WebSocketTest.cpp
index 88a95a6ebb..18a3ccab62 100644
--- a/wpiutil/src/test/native/cpp/WebSocketTest.cpp
+++ b/wpiutil/src/test/native/cpp/WebSocketTest.cpp
@@ -7,6 +7,7 @@
 #include "WebSocketTest.h"
 
 #include "wpi/HttpParser.h"
+#include "wpi/StringExtras.h"
 
 namespace wpi {
 
@@ -106,24 +107,24 @@ TEST_F(WebSocketTest, CreateClientBasic) {
   int gotVersion = 0;
 
   HttpParser req{HttpParser::kRequest};
-  req.url.connect([](StringRef url) { ASSERT_EQ(url, "/test"); });
-  req.header.connect([&](StringRef name, StringRef value) {
-    if (name.equals_lower("host")) {
+  req.url.connect([](std::string_view url) { ASSERT_EQ(url, "/test"); });
+  req.header.connect([&](std::string_view name, std::string_view value) {
+    if (equals_lower(name, "host")) {
       ASSERT_EQ(value, pipeName);
       ++gotHost;
-    } else if (name.equals_lower("upgrade")) {
+    } else if (equals_lower(name, "upgrade")) {
       ASSERT_EQ(value, "websocket");
       ++gotUpgrade;
-    } else if (name.equals_lower("connection")) {
+    } else if (equals_lower(name, "connection")) {
       ASSERT_EQ(value, "Upgrade");
       ++gotConnection;
-    } else if (name.equals_lower("sec-websocket-key")) {
+    } else if (equals_lower(name, "sec-websocket-key")) {
       ++gotKey;
-    } else if (name.equals_lower("sec-websocket-version")) {
+    } else if (equals_lower(name, "sec-websocket-version")) {
       ASSERT_EQ(value, "13");
       ++gotVersion;
     } else {
-      FAIL() << "unexpected header " << name.str();
+      FAIL() << "unexpected header " << name;
     }
   });
   req.headersComplete.connect([&](bool) { Finish(); });
@@ -132,7 +133,7 @@ TEST_F(WebSocketTest, CreateClientBasic) {
     auto conn = serverPipe->Accept();
     conn->StartRead();
     conn->data.connect([&](uv::Buffer& buf, size_t size) {
-      req.Execute(StringRef{buf.base, size});
+      req.Execute(std::string_view{buf.base, size});
       if (req.HasError()) {
         Finish();
       }
@@ -159,11 +160,11 @@ TEST_F(WebSocketTest, CreateClientExtraHeaders) {
   int gotExtra1 = 0;
   int gotExtra2 = 0;
   HttpParser req{HttpParser::kRequest};
-  req.header.connect([&](StringRef name, StringRef value) {
-    if (name.equals("Extra1")) {
+  req.header.connect([&](std::string_view name, std::string_view value) {
+    if (equals(name, "Extra1")) {
       ASSERT_EQ(value, "Data1");
       ++gotExtra1;
-    } else if (name.equals("Extra2")) {
+    } else if (equals(name, "Extra2")) {
       ASSERT_EQ(value, "Data2");
       ++gotExtra2;
     }
@@ -174,7 +175,7 @@ TEST_F(WebSocketTest, CreateClientExtraHeaders) {
     auto conn = serverPipe->Accept();
     conn->StartRead();
     conn->data.connect([&](uv::Buffer& buf, size_t size) {
-      req.Execute(StringRef{buf.base, size});
+      req.Execute(std::string_view{buf.base, size});
       if (req.HasError()) {
         Finish();
       }
@@ -183,12 +184,12 @@ TEST_F(WebSocketTest, CreateClientExtraHeaders) {
   });
   clientPipe->Connect(pipeName, [&]() {
     WebSocket::ClientOptions options;
-    SmallVector<std::pair<StringRef, StringRef>, 4> extraHeaders;
+    SmallVector<std::pair<std::string_view, std::string_view>, 4> extraHeaders;
     extraHeaders.emplace_back("Extra1", "Data1");
     extraHeaders.emplace_back("Extra2", "Data2");
     options.extraHeaders = extraHeaders;
-    auto ws = WebSocket::CreateClient(*clientPipe, "/test", pipeName,
-                                      ArrayRef<StringRef>{}, options);
+    auto ws =
+        WebSocket::CreateClient(*clientPipe, "/test", pipeName, {}, options);
   });
 
   loop->Run();
@@ -206,9 +207,9 @@ TEST_F(WebSocketTest, CreateClientTimeout) {
   clientPipe->Connect(pipeName, [&]() {
     WebSocket::ClientOptions options;
     options.handshakeTimeout = uv::Timer::Time{100};
-    auto ws = WebSocket::CreateClient(*clientPipe, "/test", pipeName,
-                                      ArrayRef<StringRef>{}, options);
-    ws->closed.connect([&](uint16_t code, StringRef) {
+    auto ws =
+        WebSocket::CreateClient(*clientPipe, "/test", pipeName, {}, options);
+    ws->closed.connect([&](uint16_t code, std::string_view) {
       Finish();
       ++gotClosed;
       ASSERT_EQ(code, 1006);
@@ -231,22 +232,22 @@ TEST_F(WebSocketTest, CreateServerBasic) {
   int gotOpen = 0;
 
   HttpParser resp{HttpParser::kResponse};
-  resp.status.connect([&](StringRef status) {
+  resp.status.connect([&](std::string_view status) {
     ++gotStatus;
     ASSERT_EQ(resp.GetStatusCode(), 101u) << "status: " << status;
   });
-  resp.header.connect([&](StringRef name, StringRef value) {
-    if (name.equals_lower("upgrade")) {
+  resp.header.connect([&](std::string_view name, std::string_view value) {
+    if (equals_lower(name, "upgrade")) {
       ASSERT_EQ(value, "websocket");
       ++gotUpgrade;
-    } else if (name.equals_lower("connection")) {
+    } else if (equals_lower(name, "connection")) {
       ASSERT_EQ(value, "Upgrade");
       ++gotConnection;
-    } else if (name.equals_lower("sec-websocket-accept")) {
+    } else if (equals_lower(name, "sec-websocket-accept")) {
       ASSERT_EQ(value, "s3pPLMBiTxaQ9kYGzzhZRbK+xOo=");
       ++gotAccept;
     } else {
-      FAIL() << "unexpected header " << name.str();
+      FAIL() << "unexpected header " << name;
     }
   });
   resp.headersComplete.connect([&](bool) { Finish(); });
@@ -254,7 +255,7 @@ TEST_F(WebSocketTest, CreateServerBasic) {
   serverPipe->Listen([&]() {
     auto conn = serverPipe->Accept();
     auto ws = WebSocket::CreateServer(*conn, "dGhlIHNhbXBsZSBub25jZQ==", "13");
-    ws->open.connect([&](StringRef protocol) {
+    ws->open.connect([&](std::string_view protocol) {
       ++gotOpen;
       ASSERT_TRUE(protocol.empty());
     });
@@ -262,7 +263,7 @@ TEST_F(WebSocketTest, CreateServerBasic) {
   clientPipe->Connect(pipeName, [&] {
     clientPipe->StartRead();
     clientPipe->data.connect([&](uv::Buffer& buf, size_t size) {
-      resp.Execute(StringRef{buf.base, size});
+      resp.Execute(std::string_view{buf.base, size});
       if (resp.HasError()) {
         Finish();
       }
@@ -287,8 +288,8 @@ TEST_F(WebSocketTest, CreateServerProtocol) {
   int gotOpen = 0;
 
   HttpParser resp{HttpParser::kResponse};
-  resp.header.connect([&](StringRef name, StringRef value) {
-    if (name.equals_lower("sec-websocket-protocol")) {
+  resp.header.connect([&](std::string_view name, std::string_view value) {
+    if (equals_lower(name, "sec-websocket-protocol")) {
       ++gotProtocol;
       ASSERT_EQ(value, "myProtocol");
     }
@@ -298,7 +299,7 @@ TEST_F(WebSocketTest, CreateServerProtocol) {
   serverPipe->Listen([&]() {
     auto conn = serverPipe->Accept();
     auto ws = WebSocket::CreateServer(*conn, "foo", "13", "myProtocol");
-    ws->open.connect([&](StringRef protocol) {
+    ws->open.connect([&](std::string_view protocol) {
       ++gotOpen;
       ASSERT_EQ(protocol, "myProtocol");
     });
@@ -306,7 +307,7 @@ TEST_F(WebSocketTest, CreateServerProtocol) {
   clientPipe->Connect(pipeName, [&] {
     clientPipe->StartRead();
     clientPipe->data.connect([&](uv::Buffer& buf, size_t size) {
-      resp.Execute(StringRef{buf.base, size});
+      resp.Execute(std::string_view{buf.base, size});
       if (resp.HasError()) {
         Finish();
       }
@@ -329,19 +330,19 @@ TEST_F(WebSocketTest, CreateServerBadVersion) {
   int gotUpgrade = 0;
 
   HttpParser resp{HttpParser::kResponse};
-  resp.status.connect([&](StringRef status) {
+  resp.status.connect([&](std::string_view status) {
     ++gotStatus;
     ASSERT_EQ(resp.GetStatusCode(), 426u) << "status: " << status;
   });
-  resp.header.connect([&](StringRef name, StringRef value) {
-    if (name.equals_lower("sec-websocket-version")) {
+  resp.header.connect([&](std::string_view name, std::string_view value) {
+    if (equals_lower(name, "sec-websocket-version")) {
       ++gotVersion;
       ASSERT_EQ(value, "13");
-    } else if (name.equals_lower("upgrade")) {
+    } else if (equals_lower(name, "upgrade")) {
       ++gotUpgrade;
       ASSERT_EQ(value, "WebSocket");
     } else {
-      FAIL() << "unexpected header " << name.str();
+      FAIL() << "unexpected header " << name;
     }
   });
   resp.headersComplete.connect([&](bool) { Finish(); });
@@ -349,7 +350,7 @@ TEST_F(WebSocketTest, CreateServerBadVersion) {
   serverPipe->Listen([&] {
     auto conn = serverPipe->Accept();
     auto ws = WebSocket::CreateServer(*conn, "foo", "14");
-    ws->open.connect([&](StringRef) {
+    ws->open.connect([&](std::string_view) {
       Finish();
       FAIL();
     });
@@ -357,7 +358,7 @@ TEST_F(WebSocketTest, CreateServerBadVersion) {
   clientPipe->Connect(pipeName, [&] {
     clientPipe->StartRead();
     clientPipe->data.connect([&](uv::Buffer& buf, size_t size) {
-      resp.Execute(StringRef{buf.base, size});
+      resp.Execute(std::string_view{buf.base, size});
       if (resp.HasError()) {
         Finish();
       }
diff --git a/wpiutil/src/test/native/cpp/json/unit-unicode.cpp b/wpiutil/src/test/native/cpp/json/unit-unicode.cpp
index e0179b62f8..6755fe2978 100644
--- a/wpiutil/src/test/native/cpp/json/unit-unicode.cpp
+++ b/wpiutil/src/test/native/cpp/json/unit-unicode.cpp
@@ -37,7 +37,7 @@ SOFTWARE.
 #include "unit-json.h"
 using wpi::json;
 
-#include "wpi/Format.h"
+#include "fmt/format.h"
 #include "wpi/StringExtras.h"
 #include "wpi/raw_ostream.h"
 
@@ -919,11 +919,7 @@ static std::string codepoint_to_unicode(std::size_t cp)
     // reverse solidus, followed by the lowercase letter u, followed
     // by four hexadecimal digits that encode the character's code
     // point
-    std::string s;
-    wpi::raw_string_ostream ss(s);
-    ss << "\\u" << wpi::format_hex_no_prefix(cp, 4);
-    ss.flush();
-    return s;
+    return fmt::format("\\u{:04x}", cp);
 }
 
 // correct sequences
diff --git a/wpiutil/src/test/native/cpp/leb128Test.cpp b/wpiutil/src/test/native/cpp/leb128Test.cpp
index d423b00a41..7b02935dce 100644
--- a/wpiutil/src/test/native/cpp/leb128Test.cpp
+++ b/wpiutil/src/test/native/cpp/leb128Test.cpp
@@ -14,23 +14,23 @@
 #include <stdint.h>
 
 #include <string>
+#include <string_view>
 
 #include "gtest/gtest.h"
 #include "wpi/SmallString.h"
-#include "wpi/StringRef.h"
 #include "wpi/leb128.h"
 #include "wpi/raw_istream.h"
 
 namespace wpi {
 
 TEST(LEB128Test, WriteUleb128) {
-#define EXPECT_ULEB128_EQ(EXPECTED, VALUE, PAD)         \
-  do {                                                  \
-    StringRef expected(EXPECTED, sizeof(EXPECTED) - 1); \
-    SmallString<32> buf;                                \
-    size_t size = WriteUleb128(buf, VALUE);             \
-    EXPECT_EQ(size, buf.size());                        \
-    EXPECT_EQ(expected, buf.str());                     \
+#define EXPECT_ULEB128_EQ(EXPECTED, VALUE, PAD)                \
+  do {                                                         \
+    std::string_view expected(EXPECTED, sizeof(EXPECTED) - 1); \
+    SmallString<32> buf;                                       \
+    size_t size = WriteUleb128(buf, VALUE);                    \
+    EXPECT_EQ(size, buf.size());                               \
+    EXPECT_EQ(expected, buf.str());                            \
   } while (0)
 
   // Write ULEB128
diff --git a/wpiutil/src/test/native/cpp/uv/UvGetAddrInfoTest.cpp b/wpiutil/src/test/native/cpp/uv/UvGetAddrInfoTest.cpp
index 590add2ebc..a8191ce7ac 100644
--- a/wpiutil/src/test/native/cpp/uv/UvGetAddrInfoTest.cpp
+++ b/wpiutil/src/test/native/cpp/uv/UvGetAddrInfoTest.cpp
@@ -43,7 +43,7 @@ TEST(UvGetAddrInfo, BothNull) {
   });
 
   GetAddrInfo(
-      loop, [](const addrinfo&) { FAIL(); }, Twine::createNull());
+      loop, [](const addrinfo&) { FAIL(); }, "");
   loop->Run();
   ASSERT_EQ(fail_cb_called, 1);
 }