Contains configuration files for X client and server applications. This includes configurationfiles for the X server itself, the fs font server, the X display managers, and many other basecomponents.It is important to note that the configuration file for the newer Fontconfig-based fontarchitecture is /etc/fonts/fonts.conf (which obsoletes the /etc/X11/XftConfig file).For more on configuring and adding fonts, refer to Section 4, “Fonts”.Because the X server performs advanced tasks on a wide array of hardware, it requires detailedconfiguration. The installation program installs and configures X automatically, unless theX11R6.8 release packages are not selected for installation. However, if the monitor or videocard changes, X must to be reconfigured. The best way to do this is to use the X ConfigurationTool (system-config-display).To start the X Configuration Tool while in an active X session, go to the Main Menu Button(on the Panel) => System Settings => Display. After using the X Configuration Tool duringan X session, changes takes effect after logging out and logging back in. For more about usingthe X Configuration Tool, refer to the chapter titled X Window System Configuration in the RedHat Enterprise Linux System Administration Guide.In some situations, reconfiguring the X server may require manually editing its configuration file,/etc/X11/xorg.conf. For information about the structure of this file, refer to Section 3, “XServer Configuration Files”.2. Desktop Environments and Window ManagersOnce an X server is running, X client applications can connect to it and create a GUI for theuser. A range of GUIs are possible with Red Hat Enterprise Linux, from the rudimentary TabWindow Manager to the highly developed and interactive GNOME desktop environment thatmost Red Hat Enterprise Linux users are familiar with.To create the latter, more advanced GUI, two main classes of X client applications must connectto the X server: a desktop environment and a window manager.2.1. Desktop EnvironmentsA desktop environment brings together assorted X clients which, when used together, create acommon graphical user environment and development platform.Desktop environments have advanced features allowing X clients and other running processesto communicate with one another, while also allowing all applications written to work in thatenvironment to perform advanced tasks, such as drag and drop operations.Red Hat Enterprise Linux provides two desktop environments:• GNOME — The default desktop environment for Red Hat Enterprise Linux based on theGTK+ 2 graphical toolkit.Chapter 7. The X Window System100
