Ultrix is a computer operating system of the Unix -family by Digital Equipment Corporation to
run on their workstations.
Ultrix runs on DECstation[?] workstations, which are built atop MIPS R2000 and R3000 family of RISC
processors, and on DEC VAX-machines.
It's basically a BSD 4.2, with some features from 4.3 and
System V Release 2. It supports TCP/IP and DECnet networking and DEC's
X window system called DECwindows[?].
The first version of Ultrix, 1.0, was released early 1980s, and the last version, 4.5, was released in
November 1995. After this the DEC's Unix-product was DEC OSF/1 AXP[?], also known as
Digital UNIX, which is an implementation of Open Software Foundation's OSF/1 for the
DEC Alpha architecture.