“Mac OS X is a unique operating system in that it represents a rather successful coming together of paradigms ideologies, and technologies that have usually resisted each other in the past… Apple has been around since 1976, and many accounts of its history have been told. If the story of Apple as company is fascinating, so is the ‘technical’ story of Apple’s operating systems. This document discusses operating systems that Apple has created in the past, and many that it tried to create.”