Chapter 7. The X Window System
While the heart of Red Hat Linux is the kernel, for many users, the face of the
operating system is the graphical environment provided by the X
Window System, also called X.
Various windowing environments have existed in the
UNIX™ world for decades, predating many of the
current mainstream operating systems. Through the years X has become the
dominant graphical environment for UNIX-like operating systems.
The graphical environment for Red Hat Linux is supplied by
XFree86™, an open source implementation of
X. XFree86 is a large scale, rapidly developing project with hundreds of
developers around the world. It features a wide degree of support for a
variety of hardware devices and architectures and can run on a variety of
different operating systems and platforms.
The X Window System uses a client-server architecture. The X
server listens for connections from X
client applications via a network or local loopback
interface. The server communicates with the hardware, such as the video
card, monitor, keyboard, and mouse. X client applications exist in the
user-space, creating a graphical user interface
(GUI) for the user and passing user requests to the
Red Hat Linux 9 uses XFree86 version 4.x as the base X Window System, which
includes many cutting edge XFree86 technology enhancements such as 3D
hardware acceleration support, the XRender extension for anti-aliased
fonts, a modular driver based design, and support for modern video
hardware and input devices.
Red Hat Linux no longer provides XFree86 version 3 server packages. Before
upgrading to the latest version of Red Hat Linux, be sure the video card is
compatible with XFree86 version 4 by checking the Red Hat Hardware
Compatibility List located online at http://hardware.redhat.com.
The files related to XFree86 reside primarily in two locations:
Contains X server and some client applications as well as X header
files, libraries, modules, and documentation.
Contains configuration files for X client and server
applications. This includes configuration files for the X server
itself, the older xfs font server, the X
display managers, and many other base components.
It is important to note that the configuration file for the
newer Fontconfig-based font architecture is
/etc/fonts/fonts.conf (which obsoletes the
/etc/X11/XftConfig file). For more on
configuring and adding fonts, see Section 7.4 Fonts.
Because the XFree86 server performs advanced tasks on a wide array of
hardware, it requires detailed configuration. The Red Hat Linux installation
program installs and configures XFree86 automatically, unless the
XFree86 packages are not selected for installation. However, if the
monitor or video card changes, XFree86 will need to be reconfigured.
The best way to do this is to use the
X Configuration Tool
To start the X Configuration Tool while in an
active X session, go to the (on the
Panel) => =>
. After using the
X Configuration Tool during an X session, changes
will take effect after logging out and logging back in. For more about
using the X Configuration Tool refer to the chapter
titled Audio, Video, and General Amusement in the
Red Hat Linux Getting Started Guide.
In some situations, reconfiguring the XFree86 server may require
manually editing its configuration file,
/etc/X11/XF86Config. For information about the
structure of this file, see Section 7.3 XFree86 Server Configuration Files.