>>"Windows has been POSIX compliant for many years already."
Ehhhhh, in a sense, but not really (imo). It can offer a mostly POSIX-compliant environment. You can install Cygwin and have a POSIX world in which to play. But the functionality of Windows is a super-set of that. It would be a little like saying that C++ is C compliant. Not a fan of analogies, but I think that one works. So I concede you're sort of right, but would say that in practical terms it is not, nor tries to be.