The Classic Mac OS is a general term used to describe the Macintosh system software (Mac OS) before (and not including) Mac OS X. The term is not to be confused with the software-based Classic environment in Mac OS X. Major versions of the Classic Mac OS: * System 1 * System 2 * System 3 * System 4 * System 6 * System 7 * Mac OS 8 * Mac OS 9