The Basilisk II emulator can be used to run old versions of Mac OS 8 and System 7 on a modern Mac. Here's how to get started using it. Before macOS and OS X, there was Mac OS 9, and before that were ...

May 13, 1991: Apple releases System 7, the biggest upgrade to the Mac operating system since the original Macintosh computer shipped in 1984. The new Mac OS is whip-fast, beautiful to look at, and ...

Over the many years Apple Computer have been in operation, they have made a success of nearly-seamlessly transitioning multiple times between both operating systems and their underlying architecture.