As far as it applies to this discussion, Apple's Darwin license is effectively the same as the GPL. China can, without payment to Apple, download Darwin, modify it, and redistribute it. There you go, a fully functional BSD variant every bit as good as Linux. Yeah, well, when the bloody reds name a pirated version of OSX the official operating system of the PRC, give me a ping.
Yeah, well, when the bloody reds name a pirated version of OSX Pirating involves violation of copyright, and there would be none, unless they took the whole of OS X, which includes non-open source material.