MacOS

Mac OS is the second-most commonly used operating system after Microsoft Windows. It began in 1984 with the release of the first 128k Macintosh. For a build list see Mac OS Buildlist. Mac OS originally used the 68k architecture from 1984 to 1991, then PowerPC from 1991 to 2006 when it switched to x86 (Intel). PearPC is a useful emulator that can run PowerPC Mac OS under Windows or other x86 operating systems.

macOS
Version 10 or Mac OS X is the current incarnation of Mac OS. The first version released was Mac OS X Server in 1999. Unlike the classic Mac OS, Mac OS X is based on NeXTSTEP (OPENSTEP) and uses its frameworks (along with that of the X Window System for optimal effect.) Its versions are: