This is Chris Provenzano's MIT Pthreads library, hacked on by Michael Graff. Known working: NetBSD-1.4.2/i386 NetBSD-current/i386 Pthreads stands for POSIX threads and is based on the POSIX 1003.1c 1995 thread standard. This standard passed international Standards Organization (ISO) Committee Document (CD) balloting in February 1995 and got the IEEE Standards Board approval in June 1995.