A/UX (from Apple Unix) was Apple Computer's implementation of the Unix operating system for some of their Macintosh computers. The latest versions of A/UX run on the Macintosh II, Quadra and Centris series of machines. A/UX was first released in 1988, with the final version (3.1.1) released in 1995. A/UX requires a 68k Mac with an FPU and a paged memory management unit (PMMU).