POSIX subsystem was implemented by MS (and other major players) only to meet some bureaucratic reqs from DoD/UsGov, and i don't know any program really using it. just don't mix C library emulation of POSIX calls on top of Win32 with POSIX subsystem (btw, both are implemented on top of native Windows API)

True. I tested the posix subsystem in the early days of NT and I found that

fork actually forked nothing:. Exec after fork simply substituted the old process with the new without creation of any new process.. Then I concluded that the Posix sybsystem was there simply to pass the government requirements for public contracts. Probably, some standard executable test. Arguably, the bugs where intentionally there just to make sure that it was useless, for reasons that anyone may guess...