# OpenServer

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/OpenServer
> Markdown URL: https://mediated.wiki/source/OpenServer.md
> Source: https://en.wikipedia.org/wiki/OpenServer
> Source revision: 1350246540
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

Closed source version of Unix developed by SCO

Operating system

OpenServer SCO OpenServer 5.0.7 running the X.desktop interface Developer SCO, Caldera Systems, Caldera International, The SCO Group, Xinuos OS family UNIX System V (SVR3.2/SVR5), BSD Working state Current Source model Closed source Initial release 1989; 37 years ago (1989) Latest release OpenServer 6 Definitive 2018 SVR5 / 2017; 9 years ago (2017) Supported platforms IA-32 Kernel type Monolithic kernel Userland POSIX / SUS License Proprietary Preceded by Xenix Official website OpenServer 6 OpenServer 5

SCO OpenServer Release 5.0.7 box set

**Xinuos OpenServer**, previously **SCO UNIX** and **SCO Open Desktop** (**SCO ODT**), is a closed source computer [operating system](/source/Operating_system) developed by [Santa Cruz Operation](/source/Santa_Cruz_Operation) (SCO), later acquired by [SCO Group](/source/SCO_Group), and now owned by [Xinuos](/source/Xinuos). Early versions of OpenServer were based on [UNIX System V](/source/UNIX_System_V), while the later OpenServer 10 is based on [FreeBSD 10](/source/FreeBSD_10). However, OpenServer 10 has not received any updates since 2018 and is no longer marketed on Xinuos's website, while OpenServer 5 Definitive and 6 Definitive are still supported.

## History

### SCO UNIX/SCO Open Desktop

In 1987 [AT&T Corporation](/source/AT%26T_Corporation), [Microsoft](/source/Microsoft), and [Sun Microsystems](/source/Sun_Microsystems) agreed to combine their versions of the [Unix](/source/Unix) operating system. [Santa Cruz Operation](/source/Santa_Cruz_Operation) (SCO) sublicensed Microsoft's [Xenix](/source/Xenix) and wanted to retain the Xenix name, but AT&T said "If they want to call it Unix, they've got to use it the way it is. We don't want another set of variants".[1]

SCO UNIX was the successor to Xenix, derived from [UNIX System V Release 3.2](/source/UNIX_System_V) 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](/source/TCP%2FIP) networking or [X Window System](/source/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](/source/Symmetric_multiprocessing) package.

At the same time, AT&T completed its merge of Xenix, [BSD](/source/BSD), [SunOS](/source/SunOS), and [UNIX System V Release 3](/source/UNIX_System_V) features into [UNIX System V Release 4](/source/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 [file names](/source/File_name) and [symbolic links](/source/Symbolic_link). The next major version, OpenServer Release 5.0.0, released in 1995, added support for [ELF](/source/Executable_and_Linkable_Format) executables and dynamically linked [shared objects](/source/Shared_object), and made many kernel structures dynamic.

### SCO OpenServer

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](/source/Pizza_Hut)) and SCO Global Access, an Internet gateway server based on Open Desktop Lite.[2] To compete with [Windows NT](/source/Windows_NT) and [Linux](/source/Linux), by 1997 SCO was distributing single-user licenses for educational use for $19, the cost of the CD-ROM, or completely free at trade shows.[3] 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.[4]

SCO OpenServer 6, based on the merging of Openserver 5 and large portions of Unixware 7 was initially released by [The SCO Group](/source/The_SCO_Group) in 2005. It includes support for large files, increased memory, and multi-threaded kernel (light-weight processes). This merged codebase is [UNIX System V Release 5](/source/UNIX_System_V#SVR5_/_UnixWare_7) (SVR5) of which the original version is seen in Unixware 7; SVR5 is only used by [Xinuos](/source/Xinuos). SCO OpenServer 6 contains the [UnixWare 7](/source/UnixWare)'s SVR5 kernel integrated with SCO OpenServer 5 application and binary compatibility, OpenServer 5 system administration, and OpenServer 5 user environments. [Unixware 7](/source/UnixWare) was itself based on a merger of AT&T [UNIX](/source/UNIX) [System V](/source/System_V) Release 4.2MP ([Unixware](/source/UnixWare) 2) and select technologies from OpenServer 5.[5]

SCO OpenServer has primarily been sold into the small and medium business (SMB) market. It is widely used in small offices, [point of sale](/source/Point_of_sale) (POS) systems, replicated sites, and backoffice [database server](/source/Database_server) deployments. Prominent larger SCO OpenServer customers include [McDonald's](/source/McDonald's), [Taco Bell](/source/Taco_Bell), [Big O Tires](/source/Big_O_Tires), [Pizza Hut](/source/Pizza_Hut), [Costco](/source/Costco) pharmacy, [NASDAQ](/source/NASDAQ), The [Toronto Stock Exchange](/source/Toronto_Stock_Exchange), [Banco do Brasil](/source/Banco_do_Brasil), many banks in [Russia](/source/Russia) and [China](/source/China), and the railway system of [India](/source/India).[6][7][8]

### UnixWare merger

Commemorative cup for the SCO OpenServer 5.0.6 release

SCO purchased the right to distribute the [UnixWare](/source/UnixWare) system and its System V Release 4 code base from [Novell](/source/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](/source/Uniform_Driver_Interface) driver framework and the [USB](/source/USB) subsystem written to it.

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](/source/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.](/source/Tarantella%2C_Inc.), while Caldera Systems became [Caldera International](/source/Caldera_International), and subsequently in 2002, the [SCO Group](/source/SCO_Group).

### Under The SCO Group

OpenServer logo at the time of The SCO Group

The SCO Group continued the development and maintenance of OpenServer. On June 22, 2005, OpenServer 6.0 was released, codenamed "Legend", the first release in the new 6.0.x branch. SCO OpenServer 6 is based on the UNIX [System V Release 5](/source/UNIX_System_V#SVR5_/_UnixWare_7) kernel, a merged codebase of [UNIX System V Release 4.2MP](/source/UNIX_System_V) and [UnixWare 7](/source/UnixWare). OpenServer 6.0 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).

Some improvements over OpenServer 5 include improved SMP support (support for up to 32 processors), support for files over a terabyte on a partition (larger network files supported through NFSv3), better file system performance, and support for up to 64GB of memory.

OpenServer 6.0 maintains backward-compatibility for applications developed for Xenix 286 onwards.[9]

The SCO Group went bankrupt in 2007, after a long [series of legal battles](/source/SCO%E2%80%93Linux_controversies).

### UnXis / Xinuos (2011–present)

The rights to OpenServer, as well as UnixWare, were acquired by UnXis in 2011, which was later renamed [Xinuos](/source/Xinuos).

In June 2015, Xinuos announced OpenServer 10, which is based on the [FreeBSD](/source/FreeBSD) 10 operating system. Simultaneously, Xinuos introduced a migration path for existing customers using older OS products. In December 2015, Xinuos released "definitive" versions of OpenServer 5, OpenServer 6, and UnixWare 7.

In December 2017, Xinuos released "Definitive 2018" versions of OpenServer 6 and UnixWare 7, and in October 2018 OpenServer 5 Definitive 2018 was released. The "Definitive 2018" releases were a commitment by Xinuos to keep the legacy OS's updated and supported protecting the applications that customers need to continue to run. The Definitive 2018 products contain major updates over the Definitive releases, and an updated development kit was released which makes it easier to compile current packages for the Definitive 2018 products.

However, by 2023, OpenServer 10 was no longer listed as a product on Xinuos' home page, implying that it had been withdrawn from marketing.[10]

## Versions

Version Basis Date Codename Editions/Notes SCO UNIX System V/386 SVR3.2.0 1989 ? Currently renamed to OpenServer 5 Open Desktop 1.0 SVR3.2.1 1990 ? Open Desktop 1.1 SVR3.2v2.0 1991 ? Supplement for upgrade to 3.2v2.1 SCO UNIX SVR3.2v4.0 1992 ? Open Desktop 2.0 SVR3.2v4.1 1992 Phoenix Desktop System, Server Open Desktop/Server 3.0 SVR3.2v4.2 1994 Thunderbird Open Desktop, Open Desktop Lite, Open Server OpenServer 5.0 SVR3.2v5.0 1995 Everest Desktop System, Host System, Enterprise System OpenServer 5.0.2 SVR3.2v5.0.2 1996 Tenzing Desktop System, Host System, Enterprise System, Internet FastStart OpenServer 5.0.4 SVR3.2v5.0.4 1997 Comet Desktop System, Host System, Enterprise System OpenServer 5.0.5 SVR3.2v5.0.5 1999 Davenport Host System, Desktop System, Enterprise System OpenServer 5.0.6 SVR3.2v5.0.6 2000 Freedom Host System, Desktop System, Enterprise System OpenServer 5.0.7 SVR3.2v5.0.7 2003 Harvey West Host System, Desktop System, Enterprise System OpenServer 6.0 SVR5 2005 Legend A "merge" of UnixWare 7 and OpenServer 5 OpenServer 5.0.7V SVR3.2v5.0.7 2009 ? OpenServer 5.0.7V import a pre-installed Virtual Appliance/Machine onto the VMware hypervisor. OpenServer 10 FreeBSD 10 2015 10.0 First release based on FreeBSD 10 and Xinuos enhancements OpenServer 6 Definitive SVR5 2015 Definitive Upwards compatible with OpenServer 6 Definitive 2018 OpenServer 5 Definitive SVR3.2v5.0.7 2015 Definitive Upwards compatible with OpenServer 5 Definitive 2018 OpenServer 10.3 (discontinued) FreeBSD 10.3 2016 10.3 Release based on FreeBSD & Xinuos enhancements. Update from 10.0 and 10.2 OpenServer 6 Definitive 2018 SVR5 2017 Definitive 2018 In-place upgrade from previous supported versions OpenServer 5 Definitive 2018 SVR3.2v5.0.7 2018 Definitive 2018 In-place upgrade from previous supported versions

## See also

- [Santa Cruz Operation](/source/Santa_Cruz_Operation)

- [SCO v. Novell](/source/SCO_v._Novell)

- [SCO Skunkware](/source/SCO_Skunkware)

## References

1. **[^](#cite_ref-patton19880118_1-0)** Patton, Carole (18 January 1988). ["AT&T Unix Standard Could Impact Santa Cruz Operation"](https://books.google.com/books?id=Dz8EAAAAMBAJ&pg=PA33). *[InfoWorld](/source/InfoWorld)*. Vol. 10, no. 3. p. 33. Retrieved 2025-05-25.

1. **[^](#cite_ref-2)** Burns, Christine (7 March 1994). ["SCO to roll out Internet access software"](https://books.google.com/books?id=gQ0EAAAAMBAJ&pg=PA6). *Network World*. p. 6.

1. **[^](#cite_ref-collins19971101_3-0)** Collins, Ken (1997-11-01). ["SCO OpenServer"](https://www.linuxjournal.com/article/2427). *Linux Journal*. Retrieved 2025-05-12.

1. **[^](#cite_ref-definitive2018_4-0)** ["SCO OpenServer® 5 Definitive 2018"](https://www.xinuos.com/wp-content/uploads/OpenServer5D2M1-ReleaseNotes-201809.pdf) (PDF). *[Xinuos](/source/Xinuos)*. Retrieved 2023-02-25.

1. **[^](#cite_ref-5)** ["SCO History"](https://williambader.com/museum/dell/xenixhistory.html). *williambader.com*. Retrieved 2025-10-06.

1. **[^](#cite_ref-openservercustomers_6-0)** ["Costco Cuts Costs with SCO OpenServer"](https://web.archive.org/web/20100325234204/http://www.cdms-inc.com/pdfs/unix_windows.pdf) (PDF). *CDMS Inc*. Archived from [the original](http://cdms-inc.com/pdfs/unix_windows.pdf) (PDF) on 2010-03-25. Retrieved 2010-04-12.

1. **[^](#cite_ref-successstories_7-0)** ["OpenServer 5.0.7 Success Stories"](http://www.sco.com/company/success/search.html?select_cat=1&category_submit=true). *[The SCO Group](/source/The_SCO_Group)*. Retrieved 2010-04-12.

1. **[^](#cite_ref-groklawreport_8-0)** ["Monday's Agenda in SCO's Bankruptcy and the Letter from Russia"](https://web.archive.org/web/20100612020636/http://www.groklaw.net/articlebasic.php?story=20090611130638179). *Groklaw*. Archived from the original on 2010-06-12. Retrieved 2010-04-12.

1. **[^](#cite_ref-os6qsg_9-0)** ["SCO OpenServer Release 6 Quick Start Guide"](http://www.sco.com/products/openserver6/quickfacts.html). *SCO Group Web Site*. Retrieved 2009-10-27.

1. **[^](#cite_ref-10)** Proven, Liam (17 Jan 2023). ["Unix is dead. Long live Unix!"](https://www.theregister.com/2023/01/17/unix_is_dead/). *www.theregister.com*. Retrieved 2023-02-08.

## External links

- [SCO OpenServer 6.0 (deprecated) home page](http://www.sco.com/products/openserver6/)

- [SCO OpenServer 5.0.7 (deprecated) home page](http://www.sco.com/products/openserver507/)

- [SCO OS FAQ (3.2v4.2 and 3.2v5.0.x)](https://web.archive.org/web/20061106035811/http://aplawrence.com/SCOFAQ/)

v t e Unix and Unix-like operating systems and compatibility layers Architecture Filesystem History Philosophy Security Shell Operating systems BSD 386BSD FreeBSD NetBSD OpenBSD DragonFly BSD Darwin macOS iOS audioOS iPadOS tvOS watchOS bridgeOS DYNIX NeXTSTEP SunOS Ultrix Linux Android Arch ChromeOS Debian Fedora Gentoo Red Hat Slackware SUSE Ubuntu Other distributions System V A/UX AIX HP-UX IRIX OpenServer Solaris OpenSolaris Illumos Tru64 UNIX UnixWare Other Coherent Domain/OS GNU Hurd LynxOS Minix MOS OSF/1 QNX BlackBerry 10 Research Unix SerenityOS Xenix more... Compatibility layers Cygwin Darling Eunice GNV Interix MachTen Microsoft POSIX subsystem MKS Toolkit PASE P.I.P.S. PWS/VSE-AF UNIX System Services UserLAnd Technologies Windows Services for UNIX Windows Subsystem for Linux Italics indicate discontinued systems. Category Commons

v t e The FreeBSD Project FreeBSD FreeBSD Core Team FreeBSD Documentation License FreeBSD Foundation FreeBSD Ports Version History Subsystems Scheduling ALTQ ULE scheduler Virtualisation chroot jail bhyve Storage GEOM raid5 GBDE geli LVM2 vinum disklabel fdisk UFS Soft updates VFS ZFS Highly Available STorage Networking 802.11 drivers ALTQ Bluetooth BPF IPFilter ipfw Netgraph NDIS pf CARP pfsync SCTP Other busdma DTrace OpenPAM OpenBSM portsnap kqueue KLD moused systat People Matthew Dillon Jordan Hubbard Poul-Henning Kamp Mike Karels Ben Laurie Sam Leffler Marshall Kirk McKusick Diomidis Spinellis Robert Watson Dru Lavigne Derivatives open-source Chimera Linux XNU Darwin DesktopBSD DragonFly BSD FreeNAS FreeSBIE GhostBSD MidnightBSD m0n0wall OPNsense pfSense TrueOS GNU/kFreeBSD Gentoo/FreeBSD XigmaNAS proprietary Junos macOS, iOS, tvOS, and watchOS Nintendo Switch OS OpenServer 10 PlayStation 3 OS PlayStation 4 OS PlayStation Vita OS

---
Adapted from the Wikipedia article [OpenServer](https://en.wikipedia.org/wiki/OpenServer) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/OpenServer?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.