The X.Org project exists as part of a family of related projects that contribute to the development of the X Window System.

• freedesktop.org
• DRI Wiki useful information about using Direct Rendering with Xorg
• Mesa
• Cairo
• Gnome
• The K Desktop Environment
• Enlightenment
• Linux Terminal Server Project
• Cygwin/X

The freedesktop.org Software page has links to many additional projects.