Classic Mac OS

Apple operating systems from 1984 to 2001

Mac OS (originally System Software; retronymically Classic Mac OS) is the series of operating systems developed for the Macintosh family of personal computers by Apple Computer, Inc. from 1984 to 2001, starting with System 1 and ending with Mac OS 9. The Macintosh operating system is credited with having popularized the graphical user interface concept.

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