Linux Magazine includes details of the five variants of the open-source Berkeley Software Distribution (BSD) operating systems, including Apple’s
BSD-based Mac OS X.
The report states: “Mac OS X is the leading Unix desktop operating system of all time. It may not look like a Unix variant to you, but underneath its
glossy exterior lays an operating system based on the 4.4BSD-Lite2 Open Source distribution and the Open Software Foundation Mach 3.”