OpenServer

Xinuos OpenServer, previously SCO UNIX and SCO Open Desktop (SCO ODT), is a closed source computer operating system developed by Santa Cruz Operation (SCO), later acquired by SCO Group, and now owned by Xinuos. Early versions of OpenServer were based on UNIX System V, while the later OpenServer 10 is based on FreeBSD 10. SCO UNIX was the successor to the Santa Cruz Operation's variant of Microsoft Xenix, derived from UNIX System V Release 3.2 with an infusion of Xenix device drivers and utilities. SCO UNIX System V/386 Release 3.2.0 was released in 1989, as the commercial successor to SCO Xenix. The base operating system did not include TCP/IP networking or X Window System graphics; these were available as optional extra-cost add-on packages. Shortly after the release of this bare OS, SCO shipped an integrated product under the name of SCO Open Desktop, or ODT. 1994 saw the release of SCO MPX, an add-on SMP package. At the same time, AT&T completed its merge of Xenix, BSD, SunOS, and UNIX System V Release 3 features into UNIX System V Release 4. SCO UNIX remained based on System V Release 3, but eventually added home-grown versions of most of the features of Release 4. The 1992 releases of SCO UNIX 3.2v4.0 and Open Desktop 2.0 added support for long s and symbolic links. The next major version, OpenServer Release 5.0.0, released in 1995, added support for ELF executables and dynamically linked shared objects, and made many kernel structures dynamic. SCO OpenServer 5, released in 1995, would become SCO's primary product and serve as the basis for products like PizzaNet (the first Internet-based food delivery system done in partnership with Pizza Hut) and SCO Global Access, an Internet gateway server based on Open Desktop Lite. Due to its large installed base, SCO OpenServer 5 continues to be actively maintained by SCO with major updates having occurred as recently as September 2018. SCO OpenServer 6, based on the merging of AT&T UNIX System V Release 4.2MP and UnixWare 7, was initially released by The SCO Group in 2005.