A/UX is based on {AT&T} Unix System V.2.2 with numerous extensions from V.3, V.4 and BSD 4.2/4.3. It also provides full POSIX compliance.
A/UX 3.x.x incorporates System 7 for the Macintosh, thus supporting the vast majority of Macintosh applications. System 7 and Unix are fully integrated under A/UX 3.x.x with the Unix file system being seen as a disk drive by the Finder.
{jagubox's A/UX Home Page (http://jagubox.gsfc.nasa.gov/aux/Info/FAQ.auxl)}.