One or more kicks are over here: http://harvey-os.org/ is taking the open-source Plan 9 code and getting it to compile with GCC and clang, etc. They have a userspace with APE (posix) compatibility and they almost have Google Go ported and they debug it with gdb... very much a work in progress though.
Porting Plan 9 to compile with GCC and Clang, or giving it a POSIX compatibility layer seems like missing the point; Plan 9 was notable because of all the stuff it threw out despite being familiar and widely admired, from text-only output all the way down to ANSI C.
It's an environment that demands you adapt to it, rather than vice versa. POSIX doesn't need another quirky API bolted on the side, it's already got quite enough as it is.
