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How Unix is Mac OS X?

People always said ubuntu, linux is UNIX based OS, then how about mac os x? from mac os x terminal i can see most of the unix command are available does it mean mac os also built on UNIX?


4 Answers 4



Indeed 10.5 and 10.6 are Unix (tm) certified which linux is not.

To be more specific, Mac OS X is built on Darwin---a derivative of BSD---running on a Mach microkernel.


Mac OS X is based on the Berkeley Software Distribution. BSD is Unix.


Indeed it is:

Mac OS X, whose "X" represents the Roman numeral for "10" and is a prominent part of its brand identity, is a Unix-based operating system, built on technologies developed at NeXT >between the second half of the 1980s and Apple's purchase of the company in late 1996. Its sixth release Mac OS X v10.5 "Leopard" gained UNIX 03 certification while running > on Intel processors.

From: http://en.wikipedia.org/wiki/Mac_OS_X

As another poster stated it's also Unix certified: http://www.opengroup.org/openbrand/register/brand3555.htm


Mac OS X is a genetic UNIX (being a descendant of NEXTSTEP and ultimately BSD, a genetic UNIX).

It's also a UNIX-like OS (being UNIX-like).

See the relationship to UNIX and Linux here:


Note that Linux is UNIX-like but no genetic or trademark UNIX. Mac OS X is both a trademark and a genetic UNIX.