Chapter 15. Configuring Video and Managing X Windows
The X Window System is the foundation of Linux’s graphical interface. All those nice window managers and desktop environments—XFce, Enlightenment, KDE, Gnome, and so forth—run on top of X.
The X Window System is an amazing piece of work. You can run in a graphical environment, have text consoles open at the same time, and easily switch back and forth between them. The X Window System does more than draw pretty pictures; it’s a networking protocol as well. You can even log in to remote systems via X. (This is covered in Chapter 17.)
While the X Window System has been the Linux standard forever, there is a new windowing system finding acceptance: X.org. It is a fork of the XFree86© project that found sudden popularity when the 4.4 release of XFree86 adopted a licensing change that was possibly incompatible with the GPL. Fedora and Mandrake were the first on board with X.org. By the time you read this, everyone may have kissed and made up, or it may all be a jumble, with yet another distribution difference to trap the unwary. You’ll need to know which one is on your system. This command gives the version number for XFree86:
$ XFree86 -version
And this is for X.org:
$ X.org -version
X.org currently mirrors XFree86 very closely; the primary differences are in the configuration filenames and locations. However, the two will probably diverge more with time.
There is a lot of confusing terminology around the X Window System, ...