diff --git a/cscore/src/main/java/edu/wpi/cscore/VideoListener.java b/cscore/src/main/java/edu/wpi/cscore/VideoListener.java
index 6bd433a0e1..187eae09d1 100644
--- a/cscore/src/main/java/edu/wpi/cscore/VideoListener.java
+++ b/cscore/src/main/java/edu/wpi/cscore/VideoListener.java
@@ -13,7 +13,7 @@ import java.util.function.Consumer;
  * An event listener.  This calls back to a desigated callback function when
  * an event matching the specified mask is generated by the library.
  */
-public class VideoListener {
+public class VideoListener implements AutoCloseable {
   /**
    * Create an event listener.
    * @param listener Listener function
@@ -26,7 +26,13 @@ public class VideoListener {
     m_handle = CameraServerJNI.addListener(listener, eventMask, immediateNotify);
   }
 
-  public synchronized void free() {
+  @Deprecated
+  public void free() {
+    close();
+  }
+
+  @Override
+  public synchronized void close() {
     if (m_handle != 0) {
       CameraServerJNI.removeListener(m_handle);
     }
diff --git a/cscore/src/main/java/edu/wpi/cscore/VideoSink.java b/cscore/src/main/java/edu/wpi/cscore/VideoSink.java
index 4196f3da19..86e5eb14d6 100644
--- a/cscore/src/main/java/edu/wpi/cscore/VideoSink.java
+++ b/cscore/src/main/java/edu/wpi/cscore/VideoSink.java
@@ -12,7 +12,7 @@ package edu.wpi.cscore;
  * consist of multiple images (e.g. from a stereo or depth camera); these
  * are called channels.
  */
-public class VideoSink {
+public class VideoSink implements AutoCloseable {
   public enum Kind {
     kUnknown(0), kMjpeg(2), kCv(4);
     private int value;
@@ -38,7 +38,13 @@ public class VideoSink {
     m_handle = handle;
   }
 
-  public synchronized void free() {
+  @Deprecated
+  public void free() {
+    close();
+  }
+
+  @Override
+  public synchronized void close() {
     if (m_handle != 0) {
       CameraServerJNI.releaseSink(m_handle);
     }
diff --git a/cscore/src/main/java/edu/wpi/cscore/VideoSource.java b/cscore/src/main/java/edu/wpi/cscore/VideoSource.java
index 5f4acc11e9..1471ba5b45 100644
--- a/cscore/src/main/java/edu/wpi/cscore/VideoSource.java
+++ b/cscore/src/main/java/edu/wpi/cscore/VideoSource.java
@@ -12,7 +12,7 @@ package edu.wpi.cscore;
  * consist of multiple images (e.g. from a stereo or depth camera); these
  * are called channels.
  */
-public class VideoSource {
+public class VideoSource implements AutoCloseable {
   public enum Kind {
     kUnknown(0), kUsb(1), kHttp(2), kCv(4);
     private int value;
@@ -39,7 +39,13 @@ public class VideoSource {
     m_handle = handle;
   }
 
-  public synchronized void free() {
+  @Deprecated
+  public void free() {
+    close();
+  }
+
+  @Override
+  public synchronized void close() {
     if (m_handle != 0) {
       CameraServerJNI.releaseSource(m_handle);
     }
diff --git a/hal/src/main/java/edu/wpi/first/wpilibj/sim/CallbackStore.java b/hal/src/main/java/edu/wpi/first/wpilibj/sim/CallbackStore.java
index 5e307cf138..ca3bb53d49 100644
--- a/hal/src/main/java/edu/wpi/first/wpilibj/sim/CallbackStore.java
+++ b/hal/src/main/java/edu/wpi/first/wpilibj/sim/CallbackStore.java
@@ -7,9 +7,7 @@
 
 package edu.wpi.first.wpilibj.sim;
 
-import java.io.Closeable;
-
-public class CallbackStore implements Closeable {
+public class CallbackStore implements AutoCloseable {
   interface CancelCallbackFunc {
     void cancel(int index, int uid);
   }
diff --git a/ntcore/src/main/java/edu/wpi/first/networktables/NetworkTableInstance.java b/ntcore/src/main/java/edu/wpi/first/networktables/NetworkTableInstance.java
index 2c82a67cfd..758902aca1 100644
--- a/ntcore/src/main/java/edu/wpi/first/networktables/NetworkTableInstance.java
+++ b/ntcore/src/main/java/edu/wpi/first/networktables/NetworkTableInstance.java
@@ -34,7 +34,7 @@ import java.util.function.Consumer;
  * A reference must be kept to the NetworkTableInstance returned by this
  * function to keep it from being garbage collected.
  */
-public final class NetworkTableInstance {
+public final class NetworkTableInstance implements AutoCloseable {
   /**
    * Client/server mode flag values (as returned by {@link #getNetworkMode()}).
    * This is a bitmask.
@@ -59,10 +59,16 @@ public final class NetworkTableInstance {
     m_handle = handle;
   }
 
+  @Deprecated
+  public void free() {
+    close();
+  }
+
   /**
    * Destroys the instance (if created by {@link #create()}).
    */
-  public synchronized void free() {
+  @Override
+  public synchronized void close() {
     if (m_owned && m_handle != 0) {
       NetworkTablesJNI.destroyInstance(m_handle);
     }
diff --git a/ntcore/src/main/java/edu/wpi/first/networktables/RpcAnswer.java b/ntcore/src/main/java/edu/wpi/first/networktables/RpcAnswer.java
index 0879563cf9..03c6fca4fb 100644
--- a/ntcore/src/main/java/edu/wpi/first/networktables/RpcAnswer.java
+++ b/ntcore/src/main/java/edu/wpi/first/networktables/RpcAnswer.java
@@ -10,7 +10,7 @@ package edu.wpi.first.networktables;
 /**
  * NetworkTables Remote Procedure Call (Server Side).
  */
-public final class RpcAnswer {
+public final class RpcAnswer implements AutoCloseable {
   /** Entry handle. */
   public final int entry;
 
@@ -46,10 +46,16 @@ public final class RpcAnswer {
 
   static final byte[] emptyResponse = new byte[] {};
 
+  @Deprecated
+  public void free() {
+    close();
+  }
+
   /**
    * Posts an empty response if one was not previously sent.
    */
-  public synchronized void free() {
+  @Override
+  public synchronized void close() {
     if (call != 0) {
       postResponse(emptyResponse);
     }
diff --git a/ntcore/src/main/java/edu/wpi/first/networktables/RpcCall.java b/ntcore/src/main/java/edu/wpi/first/networktables/RpcCall.java
index 6ce4fe2413..d2a37cb9ba 100644
--- a/ntcore/src/main/java/edu/wpi/first/networktables/RpcCall.java
+++ b/ntcore/src/main/java/edu/wpi/first/networktables/RpcCall.java
@@ -10,7 +10,7 @@ package edu.wpi.first.networktables;
 /**
  * NetworkTables Remote Procedure Call.
  */
-public final class RpcCall {
+public final class RpcCall implements AutoCloseable{
   /** Constructor.
    * This should generally only be used internally to NetworkTables.
    * @param entry Entry
@@ -21,10 +21,16 @@ public final class RpcCall {
     m_call = call;
   }
 
+  @Deprecated
+  public void free() {
+    close();
+  }
+
   /**
    * Cancels the result if no other action taken.
    */
-  public synchronized void free() {
+  @Override
+  public synchronized void close() {
     if (m_call != 0) {
       cancelResult();
     }
diff --git a/ntcore/src/test/java/edu/wpi/first/networktables/ConnectionListenerTest.java b/ntcore/src/test/java/edu/wpi/first/networktables/ConnectionListenerTest.java
index 08f3aa798a..10033af05d 100644
--- a/ntcore/src/test/java/edu/wpi/first/networktables/ConnectionListenerTest.java
+++ b/ntcore/src/test/java/edu/wpi/first/networktables/ConnectionListenerTest.java
@@ -26,8 +26,8 @@ public class ConnectionListenerTest extends TestCase {
 
   @Override
   protected void tearDown() throws Exception {
-    clientInst.free();
-    serverInst.free();
+    clientInst.close();
+    serverInst.close();
   }
 
   private void connect() {
diff --git a/ntcore/src/test/java/edu/wpi/first/networktables/EntryListenerTest.java b/ntcore/src/test/java/edu/wpi/first/networktables/EntryListenerTest.java
index 141ce1b6fd..18b992a1f3 100644
--- a/ntcore/src/test/java/edu/wpi/first/networktables/EntryListenerTest.java
+++ b/ntcore/src/test/java/edu/wpi/first/networktables/EntryListenerTest.java
@@ -26,8 +26,8 @@ public class EntryListenerTest extends TestCase {
 
   @Override
   protected void tearDown() throws Exception {
-    clientInst.free();
-    serverInst.free();
+    clientInst.close();
+    serverInst.close();
   }
 
   private void connect() {
diff --git a/ntcore/src/test/java/edu/wpi/first/networktables/LoggerTest.java b/ntcore/src/test/java/edu/wpi/first/networktables/LoggerTest.java
index d67a18350d..d02b2afc76 100644
--- a/ntcore/src/test/java/edu/wpi/first/networktables/LoggerTest.java
+++ b/ntcore/src/test/java/edu/wpi/first/networktables/LoggerTest.java
@@ -21,7 +21,7 @@ public class LoggerTest extends TestCase {
 
   @Override
   protected void tearDown() throws Exception {
-    clientInst.free();
+    clientInst.close();
   }
 
   public void testLogger() {
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXL345_I2C.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXL345_I2C.java
index ea21f8130c..d7994550d8 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXL345_I2C.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXL345_I2C.java
@@ -93,9 +93,9 @@ public class ADXL345_I2C extends SensorBase implements Accelerometer, Sendable {
   }
 
   @Override
-  public void free() {
-    super.free();
-    m_i2c.free();
+  public void close() {
+    super.close();
+    m_i2c.close();
   }
 
   @Override
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXL345_SPI.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXL345_SPI.java
index c6a0185cfb..429a017777 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXL345_SPI.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXL345_SPI.java
@@ -79,9 +79,9 @@ public class ADXL345_SPI extends SensorBase implements Accelerometer, Sendable {
   }
 
   @Override
-  public void free() {
-    super.free();
-    m_spi.free();
+  public void close() {
+    super.close();
+    m_spi.close();
   }
 
   /**
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXL362.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXL362.java
index 5bb8461842..aebdd66f79 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXL362.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXL362.java
@@ -93,7 +93,7 @@ public class ADXL362 extends SensorBase implements Accelerometer, Sendable {
     transferBuffer.put(1, kPartIdRegister);
     m_spi.transaction(transferBuffer, transferBuffer, 3);
     if (transferBuffer.get(2) != (byte) 0xF2) {
-      m_spi.free();
+      m_spi.close();
       m_spi = null;
       DriverStation.reportError("could not find ADXL362 on SPI port " + port.value, false);
       return;
@@ -112,10 +112,10 @@ public class ADXL362 extends SensorBase implements Accelerometer, Sendable {
   }
 
   @Override
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     if (m_spi != null) {
-      m_spi.free();
+      m_spi.close();
       m_spi = null;
     }
   }
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXRS450_Gyro.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXRS450_Gyro.java
index 1eaec6c0c2..a27db2a04f 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXRS450_Gyro.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/ADXRS450_Gyro.java
@@ -64,7 +64,7 @@ public class ADXRS450_Gyro extends GyroBase implements Gyro, PIDSource, Sendable
 
     // Validate the part ID
     if ((readRegister(kPIDRegister) & 0xff00) != 0x5200) {
-      m_spi.free();
+      m_spi.close();
       m_spi = null;
       DriverStation.reportError("could not find ADXRS450 gyro on SPI port " + port.value,
           false);
@@ -141,10 +141,10 @@ public class ADXRS450_Gyro extends GyroBase implements Gyro, PIDSource, Sendable
    * Delete (free) the spi port used for the gyro and stop accumulating.
    */
   @Override
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     if (m_spi != null) {
-      m_spi.free();
+      m_spi.close();
       m_spi = null;
     }
   }
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogAccelerometer.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogAccelerometer.java
index a7c2c82d75..f5fc17e648 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogAccelerometer.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogAccelerometer.java
@@ -67,10 +67,10 @@ public class AnalogAccelerometer extends SensorBase implements PIDSource, Sendab
    * Delete the analog components used for the accelerometer.
    */
   @Override
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     if (m_analogChannel != null && m_allocatedChannel) {
-      m_analogChannel.free();
+      m_analogChannel.close();
     }
     m_analogChannel = null;
   }
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogGyro.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogGyro.java
index b03fa9985c..9decb29986 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogGyro.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogGyro.java
@@ -119,10 +119,10 @@ public class AnalogGyro extends GyroBase implements Gyro, PIDSource, Sendable {
    * Delete (free) the accumulator and the analog components used for the gyro.
    */
   @Override
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     if (m_analog != null && m_channelAllocated) {
-      m_analog.free();
+      m_analog.close();
     }
     m_analog = null;
     AnalogGyroJNI.freeAnalogGyro(m_gyroHandle);
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogInput.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogInput.java
index bd2ba2e9bf..cb902e5e73 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogInput.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogInput.java
@@ -54,8 +54,8 @@ public class AnalogInput extends SensorBase implements PIDSource, Sendable {
    * Channel destructor.
    */
   @Override
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     AnalogJNI.freeAnalogInputPort(m_port);
     m_port = 0;
     m_channel = 0;
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogOutput.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogOutput.java
index 258fa34529..4d0783a805 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogOutput.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogOutput.java
@@ -40,8 +40,8 @@ public class AnalogOutput extends SendableBase implements Sendable {
    * Channel destructor.
    */
   @Override
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     AnalogJNI.freeAnalogOutputPort(m_port);
     m_port = 0;
     m_channel = 0;
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogPotentiometer.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogPotentiometer.java
index d2ae80b1ac..4c2e136681 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogPotentiometer.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogPotentiometer.java
@@ -158,10 +158,10 @@ public class AnalogPotentiometer extends SensorBase implements Potentiometer, Se
    * Frees this resource.
    */
   @Override
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     if (m_initAnalogInput) {
-      m_analogInput.free();
+      m_analogInput.close();
       m_analogInput = null;
       m_initAnalogInput = false;
     }
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogTrigger.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogTrigger.java
index f7f7c1ef71..090c24d297 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogTrigger.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/AnalogTrigger.java
@@ -78,12 +78,12 @@ public class AnalogTrigger extends SensorBase implements Sendable {
    * Release the resources used by this object.
    */
   @Override
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     AnalogJNI.cleanAnalogTrigger(m_port);
     m_port = 0;
     if (m_ownsAnalog && m_analogInput != null) {
-      m_analogInput.free();
+      m_analogInput.close();
     }
   }
 
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/Counter.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/Counter.java
index e0ae1e4a6c..c059190b15 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/Counter.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/Counter.java
@@ -180,8 +180,8 @@ public class Counter extends SensorBase implements CounterBase, Sendable, PIDSou
   }
 
   @Override
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     setUpdateWhenEmpty(true);
 
     clearUpSource();
@@ -222,7 +222,7 @@ public class Counter extends SensorBase implements CounterBase, Sendable, PIDSou
    */
   public void setUpSource(DigitalSource source) {
     if (m_upSource != null && m_allocatedUpSource) {
-      m_upSource.free();
+      m_upSource.close();
       m_allocatedUpSource = false;
     }
     m_upSource = source;
@@ -263,7 +263,7 @@ public class Counter extends SensorBase implements CounterBase, Sendable, PIDSou
    */
   public void clearUpSource() {
     if (m_upSource != null && m_allocatedUpSource) {
-      m_upSource.free();
+      m_upSource.close();
       m_allocatedUpSource = false;
     }
     m_upSource = null;
@@ -292,7 +292,7 @@ public class Counter extends SensorBase implements CounterBase, Sendable, PIDSou
     requireNonNull(source, "The Digital Source given was null");
 
     if (m_downSource != null && m_allocatedDownSource) {
-      m_downSource.free();
+      m_downSource.close();
       m_allocatedDownSource = false;
     }
     CounterJNI.setCounterDownSource(m_counter, source.getPortHandleForRouting(),
@@ -332,7 +332,7 @@ public class Counter extends SensorBase implements CounterBase, Sendable, PIDSou
    */
   public void clearDownSource() {
     if (m_downSource != null && m_allocatedDownSource) {
-      m_downSource.free();
+      m_downSource.close();
       m_allocatedDownSource = false;
     }
     m_downSource = null;
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/DigitalGlitchFilter.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/DigitalGlitchFilter.java
index 2082647433..ad4a6173ba 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/DigitalGlitchFilter.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/DigitalGlitchFilter.java
@@ -43,8 +43,8 @@ public class DigitalGlitchFilter extends SensorBase {
   /**
    * Free the resources used by this object.
    */
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     if (m_channelIndex >= 0) {
       synchronized (m_mutex) {
         m_filterAllocated[m_channelIndex] = false;
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/DigitalInput.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/DigitalInput.java
index b6d57c3d73..b4da7ef667 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/DigitalInput.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/DigitalInput.java
@@ -40,8 +40,8 @@ public class DigitalInput extends DigitalSource implements Sendable {
   /**
    * Frees the resources for this output.
    */
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     if (m_interrupt != 0) {
       cancelInterrupts();
     }
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/DigitalOutput.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/DigitalOutput.java
index 0df04216a6..b2cdccfe76 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/DigitalOutput.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/DigitalOutput.java
@@ -44,8 +44,8 @@ public class DigitalOutput extends SendableBase implements Sendable {
    * Free the resources associated with a digital output.
    */
   @Override
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     // disable the pwm only if we have allocated it
     if (m_pwmGenerator != invalidPwmGenerator) {
       disablePWM();
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/DoubleSolenoid.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/DoubleSolenoid.java
index 9f4207abc7..521d3af350 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/DoubleSolenoid.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/DoubleSolenoid.java
@@ -86,11 +86,10 @@ public class DoubleSolenoid extends SolenoidBase implements Sendable {
    * Destructor.
    */
   @Override
-  public synchronized void free() {
-    super.free();
+  public synchronized void close() {
+    super.close();
     SolenoidJNI.freeSolenoidPort(m_forwardHandle);
     SolenoidJNI.freeSolenoidPort(m_reverseHandle);
-    super.free();
   }
 
   /**
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/Encoder.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/Encoder.java
index 93d70f1e82..93a862834f 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/Encoder.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/Encoder.java
@@ -294,18 +294,18 @@ public class Encoder extends SensorBase implements CounterBase, PIDSource, Senda
    * Free the resources used by this object.
    */
   @Override
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     if (m_aSource != null && m_allocatedA) {
-      m_aSource.free();
+      m_aSource.close();
       m_allocatedA = false;
     }
     if (m_bSource != null && m_allocatedB) {
-      m_bSource.free();
+      m_bSource.close();
       m_allocatedB = false;
     }
     if (m_indexSource != null && m_allocatedI) {
-      m_indexSource.free();
+      m_indexSource.close();
       m_allocatedI = false;
     }
 
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/I2C.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/I2C.java
index 7c76ac9a7d..37f442571a 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/I2C.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/I2C.java
@@ -22,7 +22,7 @@ import static java.util.Objects.requireNonNull;
  * <p>This class is intended to be used by sensor (and other I2C device) drivers. It probably should
  * not be used directly.
  */
-public class I2C {
+public class I2C implements AutoCloseable {
   public enum Port {
     kOnboard(0), kMXP(1);
 
@@ -52,10 +52,16 @@ public class I2C {
     HAL.report(tResourceType.kResourceType_I2C, deviceAddress);
   }
 
+  @Deprecated
+  public void free() {
+    close();
+  }
+
   /**
    * Destructor.
    */
-  public void free() {
+  @Override
+  public void close() {
     I2CJNI.i2CClose(m_port);
   }
 
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/InterruptableSensorBase.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/InterruptableSensorBase.java
index f690d3a745..29008f731b 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/InterruptableSensorBase.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/InterruptableSensorBase.java
@@ -48,8 +48,8 @@ public abstract class InterruptableSensorBase extends SensorBase {
    * Frees the resources for this output.
    */
   @Override
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     if (m_interrupt != 0) {
       cancelInterrupts();
     }
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/NidecBrushless.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/NidecBrushless.java
index 427cb5948f..198e64e42e 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/NidecBrushless.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/NidecBrushless.java
@@ -53,10 +53,10 @@ public class NidecBrushless extends SendableBase implements SpeedController, Mot
    * Free the resources used by this object.
    */
   @Override
-  public void free() {
-    super.free();
-    m_dio.free();
-    m_pwm.free();
+  public void close() {
+    super.close();
+    m_dio.close();
+    m_pwm.close();
   }
 
   /**
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/PIDController.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/PIDController.java
index 20c0622de0..f6c768cbb5 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/PIDController.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/PIDController.java
@@ -92,8 +92,8 @@ public class PIDController extends PIDBase implements Controller {
    * Free the PID object.
    */
   @Override
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     m_controlLoop.stop();
     m_thisMutex.lock();
     try {
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/PWM.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/PWM.java
index 4f6a98c967..d8d09a45c2 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/PWM.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/PWM.java
@@ -71,8 +71,8 @@ public class PWM extends SendableBase implements Sendable {
    * <p>Free the resource associated with the PWM channel and set the value to 0.
    */
   @Override
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     if (m_handle == 0) {
       return;
     }
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/Relay.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/Relay.java
index 25323f0ee3..af5e6ee605 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/Relay.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/Relay.java
@@ -141,8 +141,8 @@ public class Relay extends SendableBase implements MotorSafety, Sendable {
   }
 
   @Override
-  public void free() {
-    super.free();
+  public void close() {
+    super.close();
     freeRelay();
   }
 
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/RobotBase.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/RobotBase.java
index ade0e07308..b80d48f36a 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/RobotBase.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/RobotBase.java
@@ -32,7 +32,7 @@ import edu.wpi.first.wpilibj.util.WPILibVersion;
  * run to completion before the OperatorControl code could start. In the future the Autonomous code
  * might be spawned as a task, then killed at the end of the Autonomous period.
  */
-public abstract class RobotBase {
+public abstract class RobotBase implements AutoCloseable {
   /**
    * The ID of the main Java thread.
    */
@@ -93,10 +93,15 @@ public abstract class RobotBase {
     LiveWindow.setEnabled(false);
   }
 
+  @Deprecated
+  public void free() {
+  }
+
   /**
    * Free the resources for a RobotBase class.
    */
-  public void free() {
+  @Override
+  public void close() {
   }
 
   /**
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/RobotDrive.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/RobotDrive.java
index b47e3e157e..8c69eff9b7 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/RobotDrive.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/RobotDrive.java
@@ -25,7 +25,7 @@ import static java.util.Objects.requireNonNull;
  *             or {@link edu.wpi.first.wpilibj.drive.MecanumDrive} classes instead.
  */
 @Deprecated
-public class RobotDrive implements MotorSafety {
+public class RobotDrive implements MotorSafety, AutoCloseable {
   protected MotorSafetyHelper m_safetyHelper;
 
   /**
@@ -662,22 +662,28 @@ public class RobotDrive implements MotorSafety {
     m_maxOutput = maxOutput;
   }
 
+  @Deprecated
+  public void free() {
+    close();
+  }
+
   /**
    * Free the speed controllers if they were allocated locally.
    */
-  public void free() {
+  @Override
+  public void close() {
     if (m_allocatedSpeedControllers) {
       if (m_frontLeftMotor != null) {
-        ((PWM) m_frontLeftMotor).free();
+        ((PWM) m_frontLeftMotor).close();
       }
       if (m_frontRightMotor != null) {
-        ((PWM) m_frontRightMotor).free();
+        ((PWM) m_frontRightMotor).close();
       }
       if (m_rearLeftMotor != null) {
-        ((PWM) m_rearLeftMotor).free();
+        ((PWM) m_rearLeftMotor).close();
       }
       if (m_rearRightMotor != null) {
-        ((PWM) m_rearRightMotor).free();
+        ((PWM) m_rearRightMotor).close();
       }
     }
   }
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/SPI.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/SPI.java
index 3ee373930d..b882f9be92 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/SPI.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/SPI.java
@@ -16,7 +16,7 @@ import edu.wpi.first.wpilibj.hal.SPIJNI;
 /**
  * Represents a SPI bus port.
  */
-public class SPI {
+public class SPI implements AutoCloseable {
   public enum Port {
     kOnboardCS0(0), kOnboardCS1(1), kOnboardCS2(2), kOnboardCS3(3), kMXP(4);
 
@@ -49,12 +49,19 @@ public class SPI {
     HAL.report(tResourceType.kResourceType_SPI, devices);
   }
 
+
+  @Deprecated
+  public void free() {
+    close();
+  }
+
   /**
    * Free the resources used by this object.
    */
-  public void free() {
+  @Override
+  public void close() {
     if (m_accum != null) {
-      m_accum.free();
+      m_accum.close();
       m_accum = null;
     }
     SPIJNI.spiClose(m_port);
@@ -416,7 +423,7 @@ public class SPI {
 
   private static final int kAccumulateDepth = 2048;
 
-  private static class Accumulator {
+  private static class Accumulator implements AutoCloseable {
     Accumulator(int port, int xferSize, int validMask, int validValue, int dataShift,
                 int dataSize, boolean isSigned, boolean bigEndian) {
       m_notifier = new Notifier(this::update);
@@ -432,7 +439,8 @@ public class SPI {
       m_port = port;
     }
 
-    void free() {
+    @Override
+    public void close() {
       m_notifier.stop();
     }
 
@@ -570,7 +578,7 @@ public class SPI {
    */
   public void freeAccumulator() {
     if (m_accum != null) {
-      m_accum.free();
+      m_accum.close();
       m_accum = null;
     }
     freeAuto();
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/SendableBase.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/SendableBase.java
index ffa64ffc9f..8937c408c2 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/SendableBase.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/SendableBase.java
@@ -13,7 +13,7 @@ import edu.wpi.first.wpilibj.livewindow.LiveWindow;
  * Base class for all sensors. Stores most recent status information as well as containing utility
  * functions for checking channels and error processing.
  */
-public abstract class SendableBase implements Sendable {
+public abstract class SendableBase implements Sendable, AutoCloseable {
   private String m_name = "";
   private String m_subsystem = "Ungrouped";
 
@@ -35,10 +35,16 @@ public abstract class SendableBase implements Sendable {
     }
   }
 
+  @Deprecated
+  public void free() {
+    close();
+  }
+
   /**
    * Free the resources used by this object.
    */
-  public void free() {
+  @Override
+  public void close() {
     LiveWindow.remove(this);
   }
 
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/SerialPort.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/SerialPort.java
index fabff3f474..c2bbaf53a2 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/SerialPort.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/SerialPort.java
@@ -197,7 +197,7 @@ public class SerialPort {
   /**
    * Destructor.
    */
-  public void free() {
+  public void close() {
     SerialPortJNI.serialClose(m_port);
   }
 
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/Solenoid.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/Solenoid.java
index a50c5fc161..c61e140ebb 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/Solenoid.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/Solenoid.java
@@ -55,8 +55,8 @@ public class Solenoid extends SolenoidBase implements Sendable {
    * Destructor.
    */
   @Override
-  public synchronized void free() {
-    super.free();
+  public synchronized void close() {
+    super.close();
     SolenoidJNI.freeSolenoidPort(m_solenoidHandle);
     m_solenoidHandle = 0;
   }
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/Ultrasonic.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/Ultrasonic.java
index a89f088db7..3ebb8a0b27 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/Ultrasonic.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/Ultrasonic.java
@@ -191,21 +191,21 @@ public class Ultrasonic extends SensorBase implements PIDSource, Sendable {
    * sensor).
    */
   @Override
-  public synchronized void free() {
-    super.free();
+  public synchronized void close() {
+    super.close();
     final boolean wasAutomaticMode = m_automaticEnabled;
     setAutomaticMode(false);
     if (m_allocatedChannels) {
       if (m_pingChannel != null) {
-        m_pingChannel.free();
+        m_pingChannel.close();
       }
       if (m_echoChannel != null) {
-        m_echoChannel.free();
+        m_echoChannel.close();
       }
     }
 
     if (m_counter != null) {
-      m_counter.free();
+      m_counter.close();
       m_counter = null;
     }
 
diff --git a/wpilibj/src/main/java/edu/wpi/first/wpilibj/interfaces/Gyro.java b/wpilibj/src/main/java/edu/wpi/first/wpilibj/interfaces/Gyro.java
index 42774256b7..a752d6ed72 100644
--- a/wpilibj/src/main/java/edu/wpi/first/wpilibj/interfaces/Gyro.java
+++ b/wpilibj/src/main/java/edu/wpi/first/wpilibj/interfaces/Gyro.java
@@ -10,7 +10,7 @@ package edu.wpi.first.wpilibj.interfaces;
 /**
  * Interface for yaw rate gyros.
  */
-public interface Gyro {
+public interface Gyro extends AutoCloseable {
   /**
    * Calibrate the gyro by running for a number of samples and computing the center value. Then use
    * the center value as the Accumulator center value for subsequent measurements. It's important to
@@ -52,5 +52,12 @@ public interface Gyro {
   /**
    * Free the resources used by the gyro.
    */
+  @Deprecated
   void free();
+
+  /**
+   * Free the resources used by the gyro.
+   */
+  @Override
+  void close();
 }
diff --git a/wpilibj/src/test/java/edu/wpi/first/wpilibj/PIDToleranceTest.java b/wpilibj/src/test/java/edu/wpi/first/wpilibj/PIDToleranceTest.java
index 1da0c9f14b..fe79ffccf8 100644
--- a/wpilibj/src/test/java/edu/wpi/first/wpilibj/PIDToleranceTest.java
+++ b/wpilibj/src/test/java/edu/wpi/first/wpilibj/PIDToleranceTest.java
@@ -66,7 +66,7 @@ public class PIDToleranceTest {
 
   @After
   public void tearDown() throws Exception {
-    m_pid.free();
+    m_pid.close();
     m_pid = null;
   }
 
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/AnalogCrossConnectTest.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/AnalogCrossConnectTest.java
index 6ccff8c79a..2c680a2e0d 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/AnalogCrossConnectTest.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/AnalogCrossConnectTest.java
@@ -78,7 +78,7 @@ public class AnalogCrossConnectTest extends AbstractInterruptTest {
     assertFalse("Analog trigger is in the window (2V, 3V)", trigger.getInWindow());
     assertFalse("Analog trigger is on", trigger.getTriggerState());
 
-    trigger.free();
+    trigger.close();
   }
 
   @Test
@@ -95,7 +95,7 @@ public class AnalogCrossConnectTest extends AbstractInterruptTest {
     assertTrue("Analog trigger is not in the window (2V, 3V)", trigger.getInWindow());
     assertFalse("Analog trigger is on", trigger.getTriggerState());
 
-    trigger.free();
+    trigger.close();
   }
 
   @Test
@@ -112,7 +112,7 @@ public class AnalogCrossConnectTest extends AbstractInterruptTest {
     assertFalse("Analog trigger is in the window (2V, 3V)", trigger.getInWindow());
     assertTrue("Analog trigger is not on", trigger.getTriggerState());
 
-    trigger.free();
+    trigger.close();
   }
 
   @Test
@@ -167,9 +167,9 @@ public class AnalogCrossConnectTest extends AbstractInterruptTest {
   @Override
   void freeInterruptableSensorBase() {
     m_interruptTriggerOutput.cancelInterrupts();
-    m_interruptTriggerOutput.free();
+    m_interruptTriggerOutput.close();
     m_interruptTriggerOutput = null;
-    m_interruptTrigger.free();
+    m_interruptTrigger.close();
     m_interruptTrigger = null;
   }
 
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/AnalogPotentiometerTest.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/AnalogPotentiometerTest.java
index dce2ac80e7..1af02f0605 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/AnalogPotentiometerTest.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/AnalogPotentiometerTest.java
@@ -42,7 +42,7 @@ public class AnalogPotentiometerTest extends AbstractComsSetup {
   @After
   public void tearDown() throws Exception {
     m_potSource.reset();
-    m_pot.free();
+    m_pot.close();
     m_analogIO.teardown();
   }
 
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/DigitalGlitchFilterTest.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/DigitalGlitchFilterTest.java
index e3e1569132..2b91208546 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/DigitalGlitchFilterTest.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/DigitalGlitchFilterTest.java
@@ -69,14 +69,14 @@ public class DigitalGlitchFilterTest extends AbstractComsSetup {
     filter3.remove(encoder5);
     filter3.remove(counter7);
 
-    input1.free();
-    input2.free();
-    input3.free();
-    input4.free();
-    encoder5.free();
-    counter7.free();
-    filter1.free();
-    filter2.free();
-    filter3.free();
+    input1.close();
+    input2.close();
+    input3.close();
+    input4.close();
+    encoder5.close();
+    counter7.close();
+    filter1.close();
+    filter2.close();
+    filter3.close();
   }
 }
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/MotorEncoderTest.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/MotorEncoderTest.java
index fa1b5868c3..f41096f1de 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/MotorEncoderTest.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/MotorEncoderTest.java
@@ -189,7 +189,7 @@ public class MotorEncoderTest extends AbstractComsSetup {
         "PID loop did not reach setpoint within 10 seconds. The current error was" + pid
             .getError(), pid.onTarget());
 
-    pid.free();
+    pid.close();
   }
 
   @Test
@@ -210,7 +210,7 @@ public class MotorEncoderTest extends AbstractComsSetup {
         "PID loop did not reach setpoint within 10 seconds. The error was: " + pid.getError(),
         pid.onTarget());
 
-    pid.free();
+    pid.close();
   }
 
   /**
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/PCMTest.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/PCMTest.java
index 4a0eae039b..4e05a9cbb0 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/PCMTest.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/PCMTest.java
@@ -63,13 +63,13 @@ public class PCMTest extends AbstractComsSetup {
 
   @AfterClass
   public static void tearDownAfterClass() throws Exception {
-    compressor.free();
+    compressor.close();
 
-    fakePressureSwitch.free();
-    fakeCompressor.free();
+    fakePressureSwitch.close();
+    fakeCompressor.close();
 
-    fakeSolenoid1.free();
-    fakeSolenoid2.free();
+    fakeSolenoid1.close();
+    fakeSolenoid2.close();
   }
 
   @Before
@@ -145,8 +145,8 @@ public class PCMTest extends AbstractComsSetup {
     assertTrue("Solenoid #1 did not report on", solenoid1.get());
     assertTrue("Solenoid #2 did not report on", solenoid2.get());
 
-    solenoid1.free();
-    solenoid2.free();
+    solenoid1.close();
+    solenoid2.close();
   }
 
   /**
@@ -177,7 +177,7 @@ public class PCMTest extends AbstractComsSetup {
     assertTrue("DoubleSolenoid did not report Reverse", solenoid.get() == DoubleSolenoid.Value
         .kReverse);
 
-    solenoid.free();
+    solenoid.close();
   }
 
   /**
@@ -265,8 +265,8 @@ public class PCMTest extends AbstractComsSetup {
     assertFalse("Solenoid #1 did not report off", solenoid1.get());
     assertFalse("Solenoid #2 did not report off", solenoid2.get());
 
-    solenoid1.free();
-    solenoid2.free();
+    solenoid1.close();
+    solenoid2.close();
   }
 
   protected Logger getClassLogger() {
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/PDPTest.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/PDPTest.java
index 22e42efcb0..e00c7001b8 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/PDPTest.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/PDPTest.java
@@ -47,7 +47,7 @@ public class PDPTest extends AbstractComsSetup {
 
   @AfterClass
   public static void tearDownAfterClass() throws Exception {
-    pdp.free();
+    pdp.close();
     pdp = null;
     me.teardown();
     me = null;
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/PIDTest.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/PIDTest.java
index f9120b4e1f..35f5064b17 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/PIDTest.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/PIDTest.java
@@ -116,7 +116,7 @@ public class PIDTest extends AbstractComsSetup {
   public void tearDown() throws Exception {
     logger.fine("Teardown: " + me.getType());
     m_controller.disable();
-    m_controller.free();
+    m_controller.close();
     m_controller = null;
     me.reset();
   }
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/AnalogCrossConnectFixture.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/AnalogCrossConnectFixture.java
index f14ceaaaa9..ece1dc93f8 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/AnalogCrossConnectFixture.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/AnalogCrossConnectFixture.java
@@ -64,8 +64,8 @@ public abstract class AnalogCrossConnectFixture implements ITestFixture {
    */
   @Override
   public boolean teardown() {
-    m_input.free();
-    m_output.free();
+    m_input.close();
+    m_output.close();
     return true;
   }
 
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/DIOCrossConnectFixture.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/DIOCrossConnectFixture.java
index de77fb973e..ade9e69e84 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/DIOCrossConnectFixture.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/DIOCrossConnectFixture.java
@@ -80,8 +80,8 @@ public class DIOCrossConnectFixture implements ITestFixture {
   public boolean teardown() {
     logger.log(Level.FINE, "Begining teardown");
     if (m_allocated) {
-      m_input.free();
-      m_output.free();
+      m_input.close();
+      m_output.close();
       m_allocated = false;
     }
     return true;
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/FakeCounterFixture.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/FakeCounterFixture.java
index bff0e4c431..a944421722 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/FakeCounterFixture.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/FakeCounterFixture.java
@@ -99,8 +99,8 @@ public class FakeCounterFixture implements ITestFixture {
   @Override
   public boolean teardown() {
     logger.log(Level.FINE, "Begining teardown");
-    m_counter.free();
-    m_source.free();
+    m_counter.close();
+    m_source.close();
     if (m_allocated) { // Only tear down the dio if this class allocated it
       m_dio.teardown();
       m_allocated = false;
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/FakeEncoderFixture.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/FakeEncoderFixture.java
index 372b2d80fa..2b2b852af6 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/FakeEncoderFixture.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/FakeEncoderFixture.java
@@ -101,9 +101,9 @@ public class FakeEncoderFixture implements ITestFixture {
   @Override
   public boolean teardown() {
     logger.fine("Begining teardown");
-    m_source.free();
+    m_source.close();
     logger.finer("Source freed " + m_sourcePort[0] + ",  " + m_sourcePort[1]);
-    m_encoder.free();
+    m_encoder.close();
     logger.finer("Encoder freed " + m_encoderPort[0] + ", " + m_encoderPort[1]);
     if (m_allocated) {
       m_dio1.teardown();
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/MotorEncoderFixture.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/MotorEncoderFixture.java
index 0a78583526..fab33060ad 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/MotorEncoderFixture.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/MotorEncoderFixture.java
@@ -181,37 +181,37 @@ public abstract class MotorEncoderFixture<T extends SpeedController> implements
     if (!m_tornDown) {
       boolean wasNull = false;
       if (m_motor instanceof PWM && m_motor != null) {
-        ((PWM) m_motor).free();
+        ((PWM) m_motor).close();
         m_motor = null;
       } else if (m_motor == null) {
         wasNull = true;
       }
       if (m_encoder != null) {
-        m_encoder.free();
+        m_encoder.close();
         m_encoder = null;
       } else {
         wasNull = true;
       }
       if (m_counters[0] != null) {
-        m_counters[0].free();
+        m_counters[0].close();
         m_counters[0] = null;
       } else {
         wasNull = true;
       }
       if (m_counters[1] != null) {
-        m_counters[1].free();
+        m_counters[1].close();
         m_counters[1] = null;
       } else {
         wasNull = true;
       }
       if (m_alphaSource != null) {
-        m_alphaSource.free();
+        m_alphaSource.close();
         m_alphaSource = null;
       } else {
         wasNull = true;
       }
       if (m_betaSource != null) {
-        m_betaSource.free();
+        m_betaSource.close();
         m_betaSource = null;
       } else {
         wasNull = true;
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/RelayCrossConnectFixture.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/RelayCrossConnectFixture.java
index ee19c9a2ee..382b4bb304 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/RelayCrossConnectFixture.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/RelayCrossConnectFixture.java
@@ -84,9 +84,9 @@ public abstract class RelayCrossConnectFixture implements ITestFixture {
   @Override
   public boolean teardown() {
     if (!m_freed) {
-      m_relay.free();
-      m_inputOne.free();
-      m_inputTwo.free();
+      m_relay.close();
+      m_inputOne.close();
+      m_inputTwo.close();
       m_freed = true;
     } else {
       throw new RuntimeException("You attempted to free the "
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/TiltPanCameraFixture.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/TiltPanCameraFixture.java
index 096c5592d6..afeaf38ec4 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/TiltPanCameraFixture.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/fixtures/TiltPanCameraFixture.java
@@ -92,22 +92,22 @@ public abstract class TiltPanCameraFixture implements ITestFixture {
   }
 
   public void freeGyro() {
-    m_gyro.free();
+    m_gyro.close();
     m_gyro = null;
   }
 
   @Override
   public boolean teardown() {
-    m_tilt.free();
+    m_tilt.close();
     m_tilt = null;
-    m_pan.free();
+    m_pan.close();
     m_pan = null;
     if (m_gyro != null) { //in case not freed during gyro tests
-      m_gyro.free();
+      m_gyro.close();
       m_gyro = null;
     }
     if (m_gyroParam != null) { //in case gyro tests failed before getting to this point
-      m_gyroParam.free();
+      m_gyroParam.close();
       m_gyroParam = null;
     }
     return true;
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/mockhardware/FakeCounterSource.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/mockhardware/FakeCounterSource.java
index a3fc9386ec..b82cb41973 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/mockhardware/FakeCounterSource.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/mockhardware/FakeCounterSource.java
@@ -13,7 +13,7 @@ import edu.wpi.first.wpilibj.Timer;
 /**
  * Simulates an encoder for testing purposes.
  */
-public class FakeCounterSource {
+public class FakeCounterSource implements AutoCloseable {
   private Thread m_task;
   private int m_count;
   private int m_milliSec;
@@ -70,10 +70,10 @@ public class FakeCounterSource {
   /**
    * Destroy Object with minimum memory leak.
    */
-  public void free() {
+  public void close() {
     m_task = null;
     if (m_allocated) {
-      m_output.free();
+      m_output.close();
       m_output = null;
       m_allocated = false;
     }
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/mockhardware/FakeEncoderSource.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/mockhardware/FakeEncoderSource.java
index 934d19d82f..dc85ec2ed3 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/mockhardware/FakeEncoderSource.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/mockhardware/FakeEncoderSource.java
@@ -13,7 +13,7 @@ import edu.wpi.first.wpilibj.Timer;
 /**
  * Emulates a quadrature encoder.
  */
-public class FakeEncoderSource {
+public class FakeEncoderSource implements AutoCloseable {
   private Thread m_task;
   private int m_count;
   private int m_milliSec;
@@ -93,11 +93,11 @@ public class FakeEncoderSource {
   /**
    * Frees the resource.
    */
-  public void free() {
+  public void close() {
     m_task = null;
     if (m_allocatedOutputs) {
-      m_outputA.free();
-      m_outputB.free();
+      m_outputA.close();
+      m_outputB.close();
     }
   }
 
diff --git a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/mockhardware/FakePotentiometerSource.java b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/mockhardware/FakePotentiometerSource.java
index 397baa8ce0..13306d366c 100644
--- a/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/mockhardware/FakePotentiometerSource.java
+++ b/wpilibjIntegrationTests/src/main/java/edu/wpi/first/wpilibj/mockhardware/FakePotentiometerSource.java
@@ -12,7 +12,7 @@ import edu.wpi.first.wpilibj.AnalogOutput;
 /**
  * A fake source to provide output to a {@link edu.wpi.first.wpilibj.interfaces.Potentiometer}.
  */
-public class FakePotentiometerSource {
+public class FakePotentiometerSource implements AutoCloseable {
   private AnalogOutput m_output;
   private boolean m_initOutput;
   private double m_potMaxAngle;
@@ -83,9 +83,9 @@ public class FakePotentiometerSource {
   /**
    * Frees the resouce.
    */
-  public void free() {
+  public void close() {
     if (m_initOutput) {
-      m_output.free();
+      m_output.close();
       m_output = null;
       m_initOutput = false;
     }