<P> 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 . </P> <P> In 1984, Apple debuted the operating system that is now known as the "Classic" Mac OS with its release of the original Macintosh System Software . The system, rebranded "Mac OS" in 1996, was preinstalled on every Macintosh until 2002 and offered on Macintosh clones for a short time in the 1990s . Noted for its ease of use, it was also criticized for its lack of modern technologies compared to its competitors . </P> <P> The current Mac operating system is macOS, originally named "Mac OS X" until 2012 and then "OS X" until 2016 . Developed between 1997 and 2001 after Apple's purchase of NeXT, Mac OS X brought an entirely new architecture based on NeXTSTEP, a Unix system, that eliminated many of the technical challenges that faced the classic Mac OS . The current macOS is preinstalled with every Mac and is updated annually . It is the basis of Apple's current system software for its other devices, iOS, watchOS, and tvOS . </P>

When did apple introduce the mac os system that prevailed until mac os x