Developed by: Apple Inc. / Bill Atkinson, Jef Raskin y Andy Hertzfeld
Launched: 1984

The Mac OS was the operating system that launched Apple Inc.'s Macintosh line of computers.

A disruptive technological leap from the "classic" Mac OS, Mac OS X was released in 2001. The new operating system was based on the University of Berkeley version of Unix, called BSD ("Berkeley Software Distribution"), and the Mach microkernel, developed by Carnegie-Mellon University. A graphical user interface called Aqua was added to this foundation.
Apple later changed its name to "macOS" in 2016.

Unlike Linux, which is licensed under the GPL, the BSD license allows the use of freely contributed code as the basis for new proprietary products.