<operating system> (Mac OS) Apple Computer, Inc.'s proprietary operating system for their Macintosh family of personal computers. The part of the operating system that simulates the desktop is called "Finder." The multitasking version of Finder was called "MultiFinder" until multitasking was integrated into the core of the OS with the introduction of System 7.0 in 1990. The Macintosh series provides a built-in graphics language, called "QuickDraw", which provides a standard for software developers. Mac OS 8, scheduled for delivery in July 1997, included new human-interface features, increased system stability and performance, a PowerPC processor-native Finder, tighter integration of Internet access through panel-based "assistants," Personal Web Sharing and the ability to run Java applets and programs through Mac OS Run Time for Java. Version 9.2 was the last version of the bespoke Mac OS. The next version, Mac OS X is quite different, being based on Unix. See also Macintosh file system, Macintosh user interface. (2007-03-15)

The family of Macintosh operating systems developed by Apple Inc. includes the graphical user interface-based operating systems it has designed for use with its Macintosh series of personal computers since 1984, as well as the related system software it once created for compatible third-party systems.

Macintosh Operating System