Does anyone here have any experience with Win32 API threading provided by HX or WDOSX + FASM?

7-ZIP with HX works usually fairly well, but there is an obscure vulnerability resulting in crashes (observed rarely during compressing with encryption) or corrupt output (observed rarely after extraction of encrypted archives). Haven't tried to access threading API using FASM code. Does WDOSX support threading at all ???

Thanks for the info but my question was about actually programming using threading and not using applications that exploit this feature. As for WDOSX you are right - it does not support threading. The fact that it supplies GetCurrentThread resulted in wrong assumption (before rereading docs) it supports complete NT style threads. It turns out that GetCurrentThread is just a stub and TEB is emulated just for compatibility reasons.