What is the Mac OS based on

Basics

Information is provided by informative website by Konrad Heuer. Here excerpts:

"The ones from the CSRG as B.erkeley S.oftware D.istribution variant was popularly known as the BSD-UNIX denotes; the last version 4.4BSD of the subsequently dissolved CSRG has been released since 1994 (Open source).

The BSDSystem has significantly shaped the UNIX world, and BSD-typical properties have developed into a quasi-standard as well as AT&T-typical elements. Most UNIX-like systems today use a mixture of both lines and, depending on the subsystem, prefer one or the other variant.

In addition to commercial variants (including AIX, BSDI, Compaq Tru64 UNIX, HP / UX, IRIX, MacOS X, SCO UNIX, Solaris / SunOS, UNICOS) there are free BSD-UNIX derivatives (Darwin, FreeBSD, NetBSD and OpenBSD) as well as free ones UNIX-like systems (Linux).

The term UNIX is generally used in a broad sense for all UNIX derivatives and often also for Linux. In principle, however, UNIX is a protected name; the naming rights have been transferred from Novell to the X / OPEN consortium of companies. The free use of the name UNIX and other protected names in this brochure should not hide the reader about the existing legal restrictions.

Darwin is the open source operating system that was created during the development of the new Mac OS X operating system from Apple. At the moment it is only stable on the Power PC architecture.

Mac OS X is the new commercial operating system from Apple, which is based on a BSD kernel and borrows many from FreeBSD and NetBSD. With Mac OS X, BSD could become the most widespread UNIX system under a Macintosh-typical interface.

Linux was created around 1990 as a completely new system based on the UNIX model, because the legal dispute with which AT&T covered the University of Berkeley made the development of a free UNIX-like system desirable. Linux is available in the form of different distributions (e.g. Caldera, Debian, RedHat, Slackware, SuSE), which differ noticeably from one another in terms of installation and administration.