(Pthreads) A POSIX standard API that defines a set of C programming language types, functions and constants for creating and manipulating pre-emptive threads. The standard's full name is "POSIX.1c, Threads extensions (IEEE Std 1003.1c-1995)". Implementations are available on many Unix-like POSIX-conformant operating systems such as FreeBSD, NetBSD, OpenBSD, GNU/Linux, Mac OS X and Solaris as well as DR-DOS and Microsoft Windows. Pthreads was designed and implemented in the PART Project (POSIX / Ada-Runtime Project).