, previously '''SCO UNIX''' and '''SCO ODT''', is a version of the
Unix computer
Operating System developed by
Santa Cruz Operation (SCO) and now maintained by the
SCO Group .
SCO UNIX was the successor to SCO
Xenix , derived from AT&T 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. Shortly after the release of this bare OS, SCO shipped an integrated product under the name of SCO Open Desktop, or ODT.
1990 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
System V features into
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
File Name s and
Symbolic Link s.
1995 's rebranded OpenServer Release 5.0.0 added support for
ELF executables and dynamically linked
Shared Object s, and made many kernel structures dynamic.
SCO purchased the
UnixWare system and its System V Release 4 code base from
Novell in
1995 . SCO was eventually able to re-use some code from that version of UnixWare in later releases of OpenServer. Until Release 6, this came primarily in the compilation system and the
UDI driver framework and the
USB subsystem written to it.
By the end of the 1990s, there were around 15,000
Value-added Reseller s (VARs) around the world who provided solutions for customers of SCO's Unix systems.
SCO announced on
August 2 ,
2000 that it would sell its Server Software and Services Divisions, as well as UnixWare and OpenServer technologies, to
Caldera Systems , Inc. The purchase was completed in May
2001 . The remaining part of the SCO company, the Tarantella Division, changed its name to
Tarantella, Inc. , while Caldera became Caldera International, and subsequently in
2002 the
SCO Group .
The SCO Group continues development and maintenance of OpenServer. They currently continue to maintain the now obsoleted 5.0.x branch derived from 3.2v5.0.x; the most recent of these is 5.0.7.
The SCO Group, on
June 22 ,
2005 , released OpenServer 6.0, codenamed "Legend", which is the culmination of a multi-year multi-million dollar development effort and the first release in the new 6.0.x branch. SCO OpenServer 6 is based upon the System V Release 5 UNIX kernel and features multi-threading application support for C, C++, and Java applications through the POSIX interface. OpenServer 6 features kernel-level threading (not found in 5.0.x), and is bundled with numerous
Open-source applications including
Apache ,
Samba ,
MySQL ,
OpenSSH ,
Mozilla Firefox ,
KDE . Some improvements over OpenServer 5 include improved SMP support (supporting up to 32 x86-family processors on a single server), support for files over 1 terabyte on a partition (larger network files supported through NFSv3), increased file system performance and up to 64GB of memory. OpenServer 6.0 maintains backward-compatibility for applications developed for Xenix 286 onwards.
