Novell' s implementation of UNIX {System 5} heavily based on Release 4.2 but with enhancements and new bundled products. In 1993 Novell acquired UNIX Systems Laboratories from AT&T along with the UNIX trademark. UNIXWare was the result of Novell' s efforts to make UNIX interoperable with {Novell NetWare}. In 1995 Novell sold UNIXWare and the rights to the UNIX operating system to SCO at a time when UNIXWare was gainnig popularity. It was later the first 64-bit operating system on the Intelplatform, and, in 1999, is the world' s fastest-growing commercial operating system. [Any connection with X/Open? URL?] (1999-11-10)