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Whither the X Window System?

Finnbarr P. Murphy <> writes on recent developments in the organization behind the X Window system.

The X Window System (also known as X11 or, more simply, X) is the de facto standard graphical environment on UNIX and Linux platforms. It has been ported to over 100 other computing platforms. It was originally developed by the Athena project at the Massachusetts Institute of Technology and was first commercially released in 1986. In 1988, the X Consortium was formed to further the development of the technology in an independent vendor-neutral consortium. In the years that followed, many successful versions of the X Window System were released. Since its inception, the X Window System has become one of the most successful consortium-developed, open standards—based technologies ever.

Stewardship of the X Window System technology has passed through a number of hands in the last few years. Upon the demise of the X Consortium in 1986, the technology was handed off to the Open Software Foundation (OSF) which, in turn, was absorbed in 1987 into The Open Group (TOG). The Open Group continued the maintenance and enhancement of the X Window system via two working groups: the X Project Team and the X Standards Team. However, in mid-1998, The Open Group terminated the X Window System project when it decided to close down the OSF facility in Cambridge, Massachusetts.

With the closing of OSF, many companies that were members of the X Project Team came together to form, an autonomous organization under the auspices of The Open Group. Founder (and executive-level) members include Compaq, Sun, Hewlett-Packard, IBM, and SGI. The mission of is the collaborative stewardship and promotion of the X Window System technology, collaboration on bug fixing and code maintenance, maintaining the sample implementation and related standards, and the engineering of appropriate enhancements driven by current and future market requirements.

Three levels of membership are available. Executive membership has the most privileges, including all releases and patches tested on a reference platform, direct access to the engineering contractor for bug fixes, a seat on the executive board, hotline support from the contractor, and much more. Premier membership is the middle tier, at which most non-OSV companies participate. Premier members include Attachmate, Barco, Jupiter Systems, Metro Link, Mitre Corporation, Sequent, Siemens, WRQ, Starnet, and Xi Graphics. Associate membership, entry level, provides companies and individuals with limited budgets a voice in the affairs of will periodically provide official X Window System releases to the general public free of charge. One annual major release each February is planned, with three patch releases (one per quarter) between each major release. As part of their membership benefits, members will get the new release ahead of the general public. How far ahead of the general public members will receive this release depends on the level of membership held.

The new Web site for is <>. A recruitment drive for additional members is under way. held its latest meeting at the 5th Linux Expo in Raleigh, North Carolina, and signed up a number of influential companies. Following an open request for proposals to provide software-engineering services, Metro Link of Fort Lauderdale, Florida, was selected as the contractor for fixing bugs, maintaining and enhancing the sample implementation, maintaining the reference platforms, and preparing the annual release and quarterly patch releases.

Several task forces have already been established:

  • Accessibility
    This task force is charged with developing an extension to the X Window System to provide better support for people who are visually impaired or who have other physical challenges that require nonstandard user input mechanisms.
  • Audio
    This task force is charged with examining how best to support audio within the X Window System.
  • Keyboard and Mouse
    This task force is looking at ways to provide better and more consistent support for keyboards, mice, and other input devices (including mice with scroll-wheels and USB devices).
  • Standards
    This task force governs the evolution of the X11R6 specification, working with appropriate groups to revise and post updates to the specifications as required. A revision of the X11R6 specifications is in progress to include the new features provided in X11R6.4 and to remove defunct, obsolescent, or unsupportable programming interfaces. Where appropriate, the output of the other task forces will become input for the standards track.
  • Desktop
    This task force is charged with examining the various desktops such as CDE, KDE, and GNOME and figuring out whether the X Window System needs to provide better support for these desktops and, if so, how that support should be provided.
  • Fonts
    This task force is charged with examining new font technologies for the X Window System (True Type fonts, Open Fonts, anti-aliased fonts, etc.) and engineering appropriate support for selected font technologies into the sample implementation.

A number of challenges face the new organization. Of primary importance is repairing the damage caused by the decision of The Open Group to introduce a commercial license for the X11R6.4 release in early 1998. The X Window System was one of the first software packages to have what is nowadays known as an open-source license. This liberal license facilitates the existence of many free or low-cost implementations of the X Window System and has contributed enormously to the growth in popularity of the X Window System and, more recently, the Linux operating system.

The introduction of a commercial license immediately caused a splintering of the X Window System development community. The Xfree86 Project <> is a nonprofit organization that manages the development of a version of the X Window System called XFree86, which runs on a wide range of Intel IA32 (and some other) platforms and various operating systems, including OS/2. This organization traditionally took the latest release of the X Window System sample implementation and rapidly merged it into their existing code base. The Xfree86 project decided to remain with the unencumbered X11R6.3 code. Recently, talks took place between the two organizations and it was agreed that the two would align their code bases and work together in the future to further the X Window System technology.

With the emergence and exponential growth of Linux and other open-source operating systems, the X Window System technology is today enjoying a major renaissance, and a number of new window managers, toolkits, and desktop managers have recently been released.

Following the late-1980 GUI wars between Motif and OpenLook, Motif emerged as the de facto standard window manager on UNIX platforms. However, Motif is not open source; it is a commercial product licensed and sold by The Open Group. The unit royalty fee charged is such that it is uneconomical for Linux operating-system vendors such as Red Hat or Metro Link to distribute Motif in their base product. As a result, the open-source community has been active in developing a number of alternative (and often incompatible) window managers and toolkits including LessTif, Qt, AfterStep, BlackBox, Enlightenment, FVWM, KDE/KWM, SCWM, QVWM, and Window Maker.

This is not necessarily good for application portability. Motif is still the de facto standard window manager for the X Window System. For this reason, X.Org is actively working with The Open Group to develop a license mechanism to deliver an open-source version of Motif for open-source platforms, which X.Org will then manage. The hope is that if a Motif open-source license is available, application developers will choose to remain with Motif.

X.Org has decided that it is not in the business of specifying the desktop metaphor. Rather, it wishes to provide the stewardship of the "plumbing" behind the desktop, that is, the X Window System and Motif technologies. X.Org feels that it is in the best interests of users if innovation in the desktop space is allowed to continue unfettered. GNOME <> and KDE <> are examples of excellent innovation in the desktop space that provide users with far better functionality than is available in Common Desktop Environment (CDE).


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Last changed: 18 Nov. 1999 jr
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