The X.Org server is a display server (English displaymanager ) and the main part of the official reference implementation of the X.Org X Window System. It is released as free software by the X.Org Foundation, which manages and develops the standards relating to the X Window System.


After around 2003 disputes had broken out because of a new license for the upcoming release of version 4.4 within the XFree86 XFree86 project, many developers left the project to develop the server based on the old license. Since the new license was also rejected by many Linux distributions as GPL - incompatible, the developer formed together with employees of different distributions of the old and the new X.Org organization X.Org Foundation to in this context, the X server and develop the X standards and manage.

The work was closely linked with that of the freedesktop.org project.


As a basis for the X.Org Pre-Release ( XFree86 4.4RC2 ) served by XFree86, which is completely based on the last release of the old license. On this basis, X.Org published on 7 April 2004 a version with the first own server under the name X11R6.7.0. This less contained new house developments rather than last patch, because they already negotiated a release candidate. The second version X11R6.8.0 was published on 8 September 2004 and contained significantly more innovations. So it allows the newly added Damage function that X clients can tell which parts were changed from windows. Thus, the clients only changed parts redraw, which is important for the network transmission of graphical output before all things. Likewise Composite Extensions experimentally implemented, which allow true transparency and shadow effects of the window.

The versions 6.9 and 7.0 are the same range of functions, but the structure is modular in the 7 Series. The aim of this modularization is an easy -to-maintain and changing code. Since the release of version 7.1, the 6 Series is no longer being developed but merely maintained with security updates.

With the introduction of modularisation many components were also given their own Versionssnummern. This is to enable certain modules such as the server kernel ( which is called katamari ) itself is independent of the overall package to be published in stable versions.

The version 7.3 the first time enabled hotplugging of output devices, which brings significant improvements (such as presentations ) especially in notebooks with them.

Server Architecture

The X.Org server communicates like most X-Window systems with the operating system kernel (usually a Linux, BSD or another UNIX kernel ) to control input and output devices. An exception is the graphics card that will be addressed by X.Org directly, bypassing the kernel (see also Direct Rendering Infrastructure). In practice X.Org frequently calls directly on keyboards and mice, without taking sufficient consideration for the working of the kernel with the appropriate equipment.

For the vast majority of graphics cards in the last 15 years, brings with X.Org own drivers. For some cards ( best known by Nvidia and ATI) there is an additional binary driver, the manufacturer will replace the X.Org driver. These proprietary drivers usually bring an improved 3D support with, but are not free software. It is also possible to allow X.Org to work on a framebuffer device, which was then a video card driver for the kernel used.

On a typical POSIX system the X.Org configuration files reside in the / etc/X11 directory. The basic configuration is done in the xorg.conf file, which contains, among other settings for the monitor, keyboard, mouse and graphics card. For the less experienced user, there are a number of (also graphical ) front-ends to facilitate the configuration of the X server. Modern distributions also provide a semi- automatic detection of the correct settings. In addition, bring newer proprietary drivers also graphical frontends with it.