While unrelated to Mac OS X, Apple came out with their version of UNIX, called A/UX, in 1988. A/UX was a POSIX compliant system based on AT&T UNIX System V (various releases) and BSD4.2/4.3, with a wide spectrum of features (STREAMS, TCP/IP, FFS, job control, NFS with YP, SCCS, printing, X Window System, compatibility with SYSV and BSD in addition to POSIX, and so on). More importantly, A/UX combined various features of the Macintosh with Unix - A/UX 3.x was a combination of the above mentioned Unix features with System 7 for the Macintosh, with the Finder and other Mac applications running under A/UX. The last version of A/UX, 3.1.1, was released in 1995. A/UX was regarded as the holy grail of Unices by some people.