As this is a significant rework of the original Threading library I have posted it in a new thread. The significant difference is that this version will operate in the IDE as well as when optimised compiled! That's right - you can now test threaded applications in the IDE - desktop and device! It seems to work fine in the IDE although obviously performance is not as good as when optimised compiled. I think it is pretty stable, I haven't experienced any crashes so far in testing so I think it is ready for the wider world. The provision for locking resources has changed significantly. The previous RunLocked methods have been removed as they were inefficient to implement under the IDE. Instead two "proper" locking objects that are thin wrappers over two of the .NET locking objects are provided. Library, help, source and demos in the zip. As before ThreadTestDevice.sbp needs my http://www.basic4ppc.com/forum/additional-libraries/1250-speech-library-device.html#post6582 EDIT :- Version 3.0 now posted for use with Basic4ppc v6.90 or later. See post #13 for details.