The Computers: Software: Operating Systems: Mac OS: System Software: (Mac OS X System Software )

Mac OS X is Apple's next-generation operating system based on BSD Unix, and Mach OS. It was released in 2001. Mac OS X System Software Mac OS Operating Systems Software Computers.

macOS (previously OS X ) is a series of Unix-based graphical interface operating systems (OS) developed and marketed by Apple Inc. (wikipedia)