The Open Group Definition

The Open Group is an international industry consortium that came into being in 1996 through a merger of the Open Software Foundation (OSF) and X/Open Company, Ltd (X/Open) for the purpose of establishing standards in software engineering.

X/Open was a consortium that was founded in 1984 for the purposes of identifying and promoting open standards in information technology. It also managed the UNIX trademark from 1993 to 1996. OSF was established in 1988 by IBM, Hewlett-Packard, Groupe Bull, Digital Equipment Corporation, Nixdorf Computer, Siemens AG and others to create an open standard for an implementation of UNIX.

A major focus of the San Francisco, California-based Open Group is standards for application programming interfaces (APIs). An API is a set of definitions of the ways in which one piece of software communicates with another, usually between application programs and an operating system.

The group is perhaps best known for its publication of the Single UNIX Specification, which provides a well-accepted alternative to POSIX (Portable Operating System Interface for uniX) standards. POSIX is a set of programming interface standards governing how to write application source code so that the applications are portable between operating systems.

The Open Group is also the owner of the UNIX trademark. This trademark and the certification rights for it were purchased by X/Open in 1994 from Novell, Inc, a Provo, Utah-based software company that had acquired UNIX-related assets from AT&T, the original developer of UNIX.

The Open Group also provides conformance testing, certifications and white papers (i.e., reports outlining policies or positions on major issues) usually concerning operating systems. In addition, it certifies some things that it does not specify and control itself, such as CORBA (Common Request Broker Architecture) implementations as specified by the Object Management Group (OMG) and the Linux Standard Base (LSB) from the Free Standards Group (FSG). The OMG is a consortium aimed at setting standards in object-oriented programming.

The FSG is an independent, nonprofit organization that was established in 2000 for the purpose of promoting the use of free software (i.e., software that that can be obtained at no cost and can be used for any purpose) through the development and promotion of international standards for such software. The Linux Standard Base is a set of interface standards designed to assure the portability of applications across Linux and other free platforms (i.e., combinations of processors and operating systems).

In mid-1997, The Open Group received control of the X Window System from the X Consortium, a non-profit vendor group established in early 1988 to direct its future development in an atmosphere that represented both commercial and educational interests. Subsequently, in May 1999, it formed X.Org, which has supervised the release of versions X11R6.5.1 onward.

The X Window System is a free, cross-platform, and complete system for managing GUIs (graphical user interfaces) on single computers and on networks of computers. It is a large and complex system, with the same order of complexity as an operating system itself, and it is one of the most useful and powerful software packages that has been developed for Linux and other Unix-like operating systems.

The Open Group has five sponsors (Fujitsu, Hewlett-Packard, Hitachi, IBM and Sun Microsystems) and more than 200 regular and academic members.

Despite its name, many Open Group papers are, in fact, available only for members.

The Open Group's home page is

Created May 10, 2005. Updated March 15, 2006.
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