`java.util.concurrent.ForkJoinPool` and `java.util.concurrent.ThreadPoolExecutor` have changed in this release to not start worker threads with the `Thread.start` method. This may impact code that constructs a `ForkJoinPool` or `ThreadPoolExecutor` with a thread factory that creates worker `Thread`s that override the no-arg `start` method. The overridden `start` method will not be invoked when worker threads are started. The change in behavior does not impact code that overrides the `ForkJoinWorkerThread.onStart()` method. The `onStart()` method will continue to be invoked by fork join worker threads when they start. A future release will re-examine the issue of thread factories creating threads that override the `start` method.