The Open Group
that Apple’s forthcoming “Leopard” operating system release is certified UNIX.
Apple has cleared the process required to qualify Mac OS X v10.5 is certified UNIX; the company has passed UNIX 03 certification. Apple joins only three other companies — Sun, IBM and HP — with certified UNIX operating systems.
The UNIX 03 certification entitles Apple to officially brand Leopard as a UNIX operating system, but more importantly, the certification also guarantees software developers considering supporting the operating system that Mac OS X libraries, system calls, commands and utilities are all vetted as real UNIX code.