Once an X server is running, X client applications can connect
to it and create a GUI for the user. A range of GUIs are possible
with Red Hat Enterprise Linux, from the rudimentary Tab Window Manager to the highly developed and
interactive GNOME desktop environment that
most Red Hat Enterprise Linux users are familiar with.
To create the latter, more advanced GUI, two main classes of X
client applications must connect to the X server: a desktop environment and a window manager.
A desktop environment brings together assorted X clients which,
when used together, create a common graphical user environment and
Desktop environments have advanced features allowing X clients
and other running processes to communicate with one another, while
also allowing all applications written to work in that environment
to perform advanced tasks, such as drag and drop operations.
Red Hat Enterprise Linux provides two desktop environments:
Both GNOME and KDE have advanced productivity applications, such
as word processors, spreadsheets, and Web browsers, and provide
tools to customize the look and feel of the GUI. Additionally, if
both the GTK+ 2 and the Qt libraries are present, KDE applications
can run in GNOME and visa versa.
Window managers are X client programs
which are either part of a desktop environment or, in some cases,
standalone. Their primary purpose is to control the way graphical
windows are positioned, resized, or moved. Window managers also
control title bars, window focus behavior, and user-specified key
and mouse button bindings.
Four window managers are included with Red Hat Enterprise
kwin — The KWin window manager is the default window manager
for KDE. It is an efficient window manager which supports custom
metacity — The Metacity window manager is the default window
manager for GNOME. It is a simple and efficient window manager
which supports custom themes.
mwm — The Motif window manager is a basic, standalone window
manager. Since it is designed to be a standalone window manager, it
should not be used in conjunction with GNOME or KDE.
twm — The minimalist Tab Window Manager, which provides the most basic
tool set of any of the window managers and can be used either as a
standalone or with a desktop environment. It is installed as part
of the X11R6.8 release.
These window managers can be run without desktop environments to
gain a better sense of their differences. To do this, type the
xinit -e <path-to-window-manager> command,
where <path-to-window-manager> is the
location of the window manager binary file. The binary file can be
found by typing which <window-manager-name>, where
<window-manager-name> is the
name of the window manager you are querying.