FWIW, OS X is UNIX 03 certified: http://www.opengroup.org/openbrand/register/brand3612.htm http://www.opengroup.org/openbrand/register/brand3612.htm Android, f

FWIW, OS X is UNIX 03 certified: http://www.opengroup.org/openbrand/register/brand3612.htm http://www.opengroup.org/openbrand/register/brand3612.htm Android, for these purposes, is, of course, Linux with a different libc, so most of the POSIXy stuff is there, even if bionic is pretty awful.