Would anyone be able to give insight on why this would be useful? Im curious, sure, but I'm at a loss to think of a use case.
replies(12):
This sounds either a bit like CoLinux, or like the POSIX subsystem revived. Remember: Windows has kernel support for different userspace APIs, and the well-known Windows API is just that: A user-mode subsystem running atop the kernel (there have been OS/2 and POSIX subsystems before).