diff --git a/CMakeLists.txt b/CMakeLists.txt
index 98bb9a3903..a58fb46b0e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 # Disable in-source builds to prevent source tree corruption.
-if(" ${CMAKE_SOURCE_DIR}" STREQUAL " ${CMAKE_BINARY_DIR}")
+if(" ${CMAKE_CURRENT_SOURCE_DIR}" STREQUAL " ${CMAKE_CURRENT_BINARY_DIR}")
   message(FATAL_ERROR "
 FATAL: In-source builds are not allowed.
        You should create a separate directory for build files.
@@ -9,17 +9,19 @@ endif()
 
 project(allwpilib)
 cmake_minimum_required(VERSION 3.3.0)
-set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/modules")
+set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_CURRENT_SOURCE_DIR}/cmake/modules")
+
+set(WPILIB_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
 
 INCLUDE(CPack)
 
 set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS TRUE)
 set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 
-set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
-set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
-set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
-set(CMAKE_JAVA_TARGET_OUTPUT_DIR ${CMAKE_BINARY_DIR}/jar)
+set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${WPILIB_BINARY_DIR}/lib)
+set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${WPILIB_BINARY_DIR}/lib)
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${WPILIB_BINARY_DIR}/bin)
+set(CMAKE_JAVA_TARGET_OUTPUT_DIR ${WPILIB_BINARY_DIR}/jar)
 
 # use, i.e. don't skip the full RPATH for the build tree
 SET(CMAKE_SKIP_BUILD_RPATH  FALSE)
@@ -192,5 +194,5 @@ if (WITH_SIMULATION_MODULES AND NOT WITH_EXTERNAL_HAL)
     add_subdirectory(simulation)
 endif()
 
-configure_file(wpilib-config.cmake.in ${CMAKE_BINARY_DIR}/wpilib-config.cmake )
-install(FILES ${CMAKE_BINARY_DIR}/wpilib-config.cmake DESTINATION ${wpilib_config_dir})
+configure_file(wpilib-config.cmake.in ${WPILIB_BINARY_DIR}/wpilib-config.cmake )
+install(FILES ${WPILIB_BINARY_DIR}/wpilib-config.cmake DESTINATION ${wpilib_config_dir})
diff --git a/cameraserver/CMakeLists.txt b/cameraserver/CMakeLists.txt
index 33e19d0dd8..aa8e65513a 100644
--- a/cameraserver/CMakeLists.txt
+++ b/cameraserver/CMakeLists.txt
@@ -53,8 +53,8 @@ else()
     set (cameraserver_config_dir share/cameraserver)
 endif()
 
-configure_file(cameraserver-config.cmake.in ${CMAKE_BINARY_DIR}/cameraserver-config.cmake )
-install(FILES ${CMAKE_BINARY_DIR}/cameraserver-config.cmake DESTINATION ${cameraserver_config_dir})
+configure_file(cameraserver-config.cmake.in ${WPILIB_BINARY_DIR}/cameraserver-config.cmake )
+install(FILES ${WPILIB_BINARY_DIR}/cameraserver-config.cmake DESTINATION ${cameraserver_config_dir})
 install(EXPORT cameraserver DESTINATION ${cameraserver_config_dir})
 
 file(GLOB multiCameraServer_src multiCameraServer/src/main/native/cpp/*.cpp)
diff --git a/cmake/toolchains/gnu.toolchain.cmake b/cmake/toolchains/gnu.toolchain.cmake
index cba08e7fbb..95156a5ad5 100644
--- a/cmake/toolchains/gnu.toolchain.cmake
+++ b/cmake/toolchains/gnu.toolchain.cmake
@@ -1,10 +1,10 @@
 cmake_minimum_required(VERSION 2.8)
 
 # load settings in case of "try compile"
-set(TOOLCHAIN_CONFIG_FILE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/toolchain.config.cmake")
+set(TOOLCHAIN_CONFIG_FILE "${WPILIB_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/toolchain.config.cmake")
 get_property(__IN_TRY_COMPILE GLOBAL PROPERTY IN_TRY_COMPILE)
 if(__IN_TRY_COMPILE)
-  include("${CMAKE_CURRENT_SOURCE_DIR}/../toolchain.config.cmake" OPTIONAL) # CMAKE_BINARY_DIR is different
+  include("${CMAKE_CURRENT_SOURCE_DIR}/../toolchain.config.cmake" OPTIONAL) # WPILIB_BINARY_DIR is different
   macro(toolchain_save_config)
     # nothing
   endmacro()
diff --git a/cscore/CMakeLists.txt b/cscore/CMakeLists.txt
index 98f6d7e2a1..cc24add830 100644
--- a/cscore/CMakeLists.txt
+++ b/cscore/CMakeLists.txt
@@ -46,8 +46,8 @@ else()
     set (cscore_config_dir share/cscore)
 endif()
 
-configure_file(cscore-config.cmake.in ${CMAKE_BINARY_DIR}/cscore-config.cmake )
-install(FILES ${CMAKE_BINARY_DIR}/cscore-config.cmake DESTINATION ${cscore_config_dir})
+configure_file(cscore-config.cmake.in ${WPILIB_BINARY_DIR}/cscore-config.cmake )
+install(FILES ${WPILIB_BINARY_DIR}/cscore-config.cmake DESTINATION ${cscore_config_dir})
 install(EXPORT cscore DESTINATION ${cscore_config_dir})
 
 SUBDIR_LIST(cscore_examples "${CMAKE_CURRENT_SOURCE_DIR}/examples")
diff --git a/hal/CMakeLists.txt b/hal/CMakeLists.txt
index 2e99064189..8bd764ffa2 100644
--- a/hal/CMakeLists.txt
+++ b/hal/CMakeLists.txt
@@ -65,8 +65,8 @@ else()
     set (hal_config_dir share/hal)
 endif()
 
-configure_file(hal-config.cmake.in ${CMAKE_BINARY_DIR}/hal-config.cmake )
-install(FILES ${CMAKE_BINARY_DIR}/hal-config.cmake DESTINATION ${hal_config_dir})
+configure_file(hal-config.cmake.in ${WPILIB_BINARY_DIR}/hal-config.cmake )
+install(FILES ${WPILIB_BINARY_DIR}/hal-config.cmake DESTINATION ${hal_config_dir})
 install(EXPORT hal DESTINATION ${hal_config_dir})
 
 # Java bindings
diff --git a/ntcore/CMakeLists.txt b/ntcore/CMakeLists.txt
index e095fa9901..160e09af75 100644
--- a/ntcore/CMakeLists.txt
+++ b/ntcore/CMakeLists.txt
@@ -26,8 +26,8 @@ else()
     set (ntcore_config_dir share/ntcore)
 endif()
 
-configure_file(ntcore-config.cmake.in ${CMAKE_BINARY_DIR}/ntcore-config.cmake )
-install(FILES ${CMAKE_BINARY_DIR}/ntcore-config.cmake DESTINATION ${ntcore_config_dir})
+configure_file(ntcore-config.cmake.in ${WPILIB_BINARY_DIR}/ntcore-config.cmake )
+install(FILES ${WPILIB_BINARY_DIR}/ntcore-config.cmake DESTINATION ${ntcore_config_dir})
 install(EXPORT ntcore DESTINATION ${ntcore_config_dir})
 
 # Java bindings
diff --git a/wpigui/CMakeLists.txt b/wpigui/CMakeLists.txt
index b0dbf43f72..59c4d6fafb 100644
--- a/wpigui/CMakeLists.txt
+++ b/wpigui/CMakeLists.txt
@@ -46,6 +46,6 @@ install(DIRECTORY src/main/native/include/ DESTINATION "${include_dest}/wpigui")
 #    set (wpigui_config_dir share/wpigui)
 #endif()
 
-#configure_file(wpigui-config.cmake.in ${CMAKE_BINARY_DIR}/wpigui-config.cmake )
-#install(FILES ${CMAKE_BINARY_DIR}/wpigui-config.cmake DESTINATION ${wpigui_config_dir})
+#configure_file(wpigui-config.cmake.in ${WPILIB_BINARY_DIR}/wpigui-config.cmake )
+#install(FILES ${WPILIB_BINARY_DIR}/wpigui-config.cmake DESTINATION ${wpigui_config_dir})
 #install(EXPORT wpigui DESTINATION ${wpigui_config_dir})
diff --git a/wpilibc/CMakeLists.txt b/wpilibc/CMakeLists.txt
index 64350405cd..d5a0102117 100644
--- a/wpilibc/CMakeLists.txt
+++ b/wpilibc/CMakeLists.txt
@@ -30,8 +30,8 @@ else()
     set (wpilibc_config_dir share/wpilibc)
 endif()
 
-configure_file(wpilibc-config.cmake.in ${CMAKE_BINARY_DIR}/wpilibc-config.cmake )
-install(FILES ${CMAKE_BINARY_DIR}/wpilibc-config.cmake DESTINATION ${wpilibc_config_dir})
+configure_file(wpilibc-config.cmake.in ${WPILIB_BINARY_DIR}/wpilibc-config.cmake )
+install(FILES ${WPILIB_BINARY_DIR}/wpilibc-config.cmake DESTINATION ${wpilibc_config_dir})
 install(EXPORT wpilibc DESTINATION ${wpilibc_config_dir})
 
 if (WITH_TESTS)
diff --git a/wpilibj/CMakeLists.txt b/wpilibj/CMakeLists.txt
index a07a563548..9a91fbe2d2 100644
--- a/wpilibj/CMakeLists.txt
+++ b/wpilibj/CMakeLists.txt
@@ -15,8 +15,8 @@ if (WITH_JAVA)
     configure_file(src/generate/WPILibVersion.java.in WPILibVersion.java)
 
     file(GLOB_RECURSE JAVA_SOURCES src/main/java/*.java)
-    file(GLOB EJML_JARS "${CMAKE_BINARY_DIR}/wpimath/thirdparty/ejml/*.jar")
-    file(GLOB JACKSON_JARS "${CMAKE_BINARY_DIR}/wpiutil/thirdparty/jackson/*.jar")
+    file(GLOB EJML_JARS "${WPILIB_BINARY_DIR}/wpimath/thirdparty/ejml/*.jar")
+    file(GLOB JACKSON_JARS "${WPILIB_BINARY_DIR}/wpiutil/thirdparty/jackson/*.jar")
 
     add_jar(wpilibj_jar ${JAVA_SOURCES} ${CMAKE_CURRENT_BINARY_DIR}/WPILibVersion.java INCLUDE_JARS hal_jar ntcore_jar ${EJML_JARS} ${JACKSON_JARS} ${OPENCV_JAR_FILE} cscore_jar cameraserver_jar wpimath_jar wpiutil_jar OUTPUT_NAME wpilibj)
 
diff --git a/wpimath/CMakeLists.txt b/wpimath/CMakeLists.txt
index a129376259..2e373486cc 100644
--- a/wpimath/CMakeLists.txt
+++ b/wpimath/CMakeLists.txt
@@ -13,9 +13,9 @@ if (WITH_JAVA)
   include(UseJava)
   set(CMAKE_JAVA_COMPILE_FLAGS "-Xlint:unchecked")
 
-  if(NOT EXISTS "${CMAKE_BINARY_DIR}/wpimath/thirdparty/ejml/ejml-simple-0.38.jar")
+  if(NOT EXISTS "${WPILIB_BINARY_DIR}/wpimath/thirdparty/ejml/ejml-simple-0.38.jar")
       set(BASE_URL "https://search.maven.org/remotecontent?filepath=")
-      set(JAR_ROOT "${CMAKE_BINARY_DIR}/wpimath/thirdparty/ejml")
+      set(JAR_ROOT "${WPILIB_BINARY_DIR}/wpimath/thirdparty/ejml")
 
       message(STATUS "Downloading EJML jarfiles...")
 
@@ -37,15 +37,15 @@ if (WITH_JAVA)
       message(STATUS "All files downloaded.")
   endif()
 
-  file(GLOB EJML_JARS "${CMAKE_BINARY_DIR}/wpimath/thirdparty/ejml/*.jar")
-  file(GLOB JACKSON_JARS "${CMAKE_BINARY_DIR}/wpiutil/thirdparty/jackson/*.jar")
+  file(GLOB EJML_JARS "${WPILIB_BINARY_DIR}/wpimath/thirdparty/ejml/*.jar")
+  file(GLOB JACKSON_JARS "${WPILIB_BINARY_DIR}/wpiutil/thirdparty/jackson/*.jar")
 
   set(CMAKE_JAVA_INCLUDE_PATH wpimath.jar ${EJML_JARS} ${JACKSON_JARS})
 
-  execute_process(COMMAND python3 ${CMAKE_SOURCE_DIR}/wpimath/generate_numbers.py ${CMAKE_BINARY_DIR}/wpimath RESULT_VARIABLE generateResult)
+  execute_process(COMMAND python3 ${CMAKE_CURRENT_SOURCE_DIR}/generate_numbers.py ${WPILIB_BINARY_DIR}/wpimath RESULT_VARIABLE generateResult)
   if(NOT (generateResult EQUAL "0"))
     # Try python
-    execute_process(COMMAND python ${CMAKE_SOURCE_DIR}/wpimath/generate_numbers.py ${CMAKE_BINARY_DIR}/wpimath RESULT_VARIABLE generateResult)
+    execute_process(COMMAND python ${CMAKE_CURRENT_SOURCE_DIR}/generate_numbers.py ${WPILIB_BINARY_DIR}/wpimath RESULT_VARIABLE generateResult)
     if(NOT (generateResult EQUAL "0"))
       message(FATAL_ERROR "python and python3 generate_numbers.py failed")
     endif()
@@ -53,7 +53,7 @@ if (WITH_JAVA)
 
   set(CMAKE_JNI_TARGET true)
 
-  file(GLOB_RECURSE JAVA_SOURCES src/main/java/*.java ${CMAKE_BINARY_DIR}/wpimath/generated/*.java)
+  file(GLOB_RECURSE JAVA_SOURCES src/main/java/*.java ${WPILIB_BINARY_DIR}/wpimath/generated/*.java)
 
   if(${CMAKE_VERSION} VERSION_LESS "3.11.0")
     set(CMAKE_JAVA_COMPILE_FLAGS "-h" "${CMAKE_CURRENT_BINARY_DIR}/jniheaders")
@@ -131,8 +131,8 @@ else()
     set (wpimath_config_dir share/wpimath)
 endif()
 
-configure_file(wpimath-config.cmake.in ${CMAKE_BINARY_DIR}/wpimath-config.cmake )
-install(FILES ${CMAKE_BINARY_DIR}/wpimath-config.cmake DESTINATION ${wpimath_config_dir})
+configure_file(wpimath-config.cmake.in ${WPILIB_BINARY_DIR}/wpimath-config.cmake )
+install(FILES ${WPILIB_BINARY_DIR}/wpimath-config.cmake DESTINATION ${wpimath_config_dir})
 install(EXPORT wpimath DESTINATION ${wpimath_config_dir})
 
 if (WITH_TESTS)
diff --git a/wpiutil/CMakeLists.txt b/wpiutil/CMakeLists.txt
index f500c89997..7fe901e605 100644
--- a/wpiutil/CMakeLists.txt
+++ b/wpiutil/CMakeLists.txt
@@ -14,9 +14,9 @@ if (WITH_JAVA)
   include(UseJava)
   set(CMAKE_JAVA_COMPILE_FLAGS "-Xlint:unchecked")
 
-  if(NOT EXISTS "${CMAKE_BINARY_DIR}/wpiutil/thirdparty/jackson/jackson-core-2.10.0.jar")
+  if(NOT EXISTS "${WPILIB_BINARY_DIR}/wpiutil/thirdparty/jackson/jackson-core-2.10.0.jar")
         set(BASE_URL "https://search.maven.org/remotecontent?filepath=")
-        set(JAR_ROOT "${CMAKE_BINARY_DIR}/wpiutil/thirdparty/jackson")
+        set(JAR_ROOT "${WPILIB_BINARY_DIR}/wpiutil/thirdparty/jackson")
 
         message(STATUS "Downloading Jackson jarfiles...")
 
@@ -31,7 +31,7 @@ if (WITH_JAVA)
     endif()
 
   file(GLOB JACKSON_JARS
-        ${CMAKE_BINARY_DIR}/wpiutil/thirdparty/jackson/*.jar)
+        ${WPILIB_BINARY_DIR}/wpiutil/thirdparty/jackson/*.jar)
 
   set(CMAKE_JAVA_INCLUDE_PATH wpiutil.jar ${JACKSON_JARS})
 
@@ -195,8 +195,8 @@ else()
     set (wpiutil_config_dir share/wpiutil)
 endif()
 
-configure_file(wpiutil-config.cmake.in ${CMAKE_BINARY_DIR}/wpiutil-config.cmake )
-install(FILES ${CMAKE_BINARY_DIR}/wpiutil-config.cmake DESTINATION ${wpiutil_config_dir})
+configure_file(wpiutil-config.cmake.in ${WPILIB_BINARY_DIR}/wpiutil-config.cmake )
+install(FILES ${WPILIB_BINARY_DIR}/wpiutil-config.cmake DESTINATION ${wpiutil_config_dir})
 install(EXPORT wpiutil DESTINATION ${wpiutil_config_dir})
 
 SUBDIR_LIST(wpiutil_examples "${CMAKE_CURRENT_SOURCE_DIR}/examples")