XFree86
XFree86 is a free and Open Source implementation of the X Window System which runs under many Unix-like operating systems, and on Windows NT as part of the Cygwin environment. Until recently, it was almost universal on Linux and the BSDs.
As of 1 October 2001, XFree86 supported the X11R6.5.1 spec, including the GLX and Render extensions.
The project began in 1991 when David Wexelblat, Glenn Lai, David Dawes and Jim Tsillas joined forces addressing bugs in the X11 X386 source code (written by Thomas Roell). This version was initially called X386 1.2e. As newer versions of the original X386 was being sold commercially by Roell under the name Accelerated-X, the project was renamed XFree86 as a pun. (Compare X-three-eighty-six to X-free-eighty-six.)
The XFree86 server communicate with the host operating systems kernel (most typically the Linux kernel) to drive input- and output devices, with the exception of graphics cards. These are used directly by XFree86, so it includes its own drivers for all graphic cards a user might have. Some cards are supported by vendors themselves via binary-only drivers.
Because of all the low level stuff X does, it needs to run as the root user, or a user with UID 0.
It is also possible to use XFree86 in a framebuffer device, which in turn use a kernel graphics card driver.
On a typical POSIX-system, /etc/X11 includes the configuration files. The basic configuration file is /etc/x11/XF86Config (or XF86Config-4) that includes variables about the screen (monitor), keyboard and graphics card. The program xf86config is often used, although xf86cfg also comes with the XFree86 server and is certainly friendlier. Many Linux distributions include a configuration tool that is easier to use (such as Debian's debconf) or autodetects most (if not all) settings (Red Hat Linux/Fedora Linux's Anaconda, SuSE's YaST and Mandrake Linux chose this path).
XFree86 4.4 was released with a change to the license: the addition of an advertising clause, similar to that in the old version of the BSD license. This has led to a great deal of controversy, and XFree86 4.4 being excluded from many Linux distributions and from OpenBSD. Some projects, such as OpenBSD, are forkinging XFree86 from version 4.4 RC2, the last version under the old license.
XFree86 used to have a Core Team which was made up of experienced developers, selected for their merits. Due to limited innovation capacity the XFree86 Core Team voted to disband itself, on December 30, 2003, effective the following day.
Earlier in 2003 Keith Packard, a noted X Window System developer, was removed from the XFree86 Core Team. The Core Team claim this was for conspiracy: Keith had been trying to "fork" the XFree86 project, working inside the project, while trying to attract core developers to a new X Server project of his own making. Packard denied this, but the Core Team produced mail conversations he had had with other developers on the subject.
Packard created XWin, a forum for the betterment of X and specifically XFree86. The XWin forum no longer exists and users are now directed to freedesktop.org. Keith Packard began a totally new development project based on the X Window System under the name Xserver, hosted by freedesktop.org. Xserver uses the Kdrive API driver model. The authors intend it to be the next generation of X server, following a different direction to XFree86.
The XOrg Foundation Open Source Public Implementation of X11 is a fork from version 4.4 RC2, owing to disagreement with the new license. It is also hosted by freedesktop.org. The XOrg Server has been adopted by Fedora Linux.
Note that the XOrg Server is a separate code base from the reference implementation of X11R6.6, also maintained by X.Org.
An experimental branch of the XFree86 server code, Xouvert, has also been announced, although this has shown no recent activity.
History
Architecture
Licensing controversy
Forks of XFree86
freedesktop.org Xserver
XOrg Foundation Open Source Public Implementation of X11
Xouvert
See also
External Links