One may feel comfortable claiming that OS X is "Unix" based on the fact that all versions of OS X since 10.5 have been "Open Brand UNIX 03 Registered Product" (from an archive of the Apple website), signifying that they have met the requirements for the SUSv3 and POSIX 1003.1 specification.
One may feel comfortable claiming that OS X is "Unix" based on the fact that all versions of OS X since 10.5 have been "Open Brand UNIX 03 Registered Product" (from an archive of the Apple website), signifying that they have met the requirements for the SUSv3 and POSIX 1003.1 specification.
http://web.archive.org/web/20070823040630/http://www.apple.c...
http://en.wikipedia.org/wiki/Single_UNIX_Specification