Doesn't really answer your question, but it's an interesting fact that OS X is officially a 'UNIX proper' (see http://en.m.wikipedia.org/wiki/Single_UNIX_Specif

Doesn't really answer your question, but it's an interesting fact that OS X is officially a 'UNIX proper' (see http://en.m.wikipedia.org/wiki/Single_UNIX_Specification http://en.m.wikipedia.org/wiki/Single_UNIX_Specification).