Red Hat Enterprise Linux uses two subsystems to manage and display fonts under X: Fontconfig and xfs.

The newer Fontconfig font subsystem simplifies font management and provides advanced display features, such as anti-aliasing. This system is used automatically for applications programmed using the Qt 3 or GTK+ 2 graphical toolkit.

For compatibility, Red Hat Enterprise Linux includes the original font subsystem, called the core X font subsystem. This system, which is over 15 years old, is based around the X Font Server (xfs).

This section discusses how to configure fonts for X using both systems.