Classic Mac OS

For the operating system used by Macs since 2001, see macOS.

Mac OS is an operating system for Macintosh computers. Mac OS was first made by Apple Inc. in 1984. In those days Mac OS was called Macintosh System Software – which was shortened to System or SSW (System Software). The term "Mac OS" first appeared in the splash screen for System 7.5.1, but was not adopted as the new name until the release of Mac OS 7.6.

Related pages

• Apple Macintosh