The Concise Guide to XFree86 for Linux by Aron Hsiao; Que — Provides an expert's view of the operation of XFree86 on Linux systems.
The New XFree86 by Bill Ball; Prima Publishing — Discuses XFree86 and its relationship with the popular desktop environments, such as GNOME and KDE.
Beginning GTK+ and GNOME by Peter Wright; Wrox Press, Inc. — Introduces programmers to the GNOME architecture, showing them how to get started with GTK+.
GTK+/GNOME Application Development by Havoc Pennington; New Riders Publishing — An advanced look into the heart of GTK+ programming, focusing on sample code and a thorough look at the available APIs.
KDE 2.0 Development by David Sweet and Matthias Ettrich; Sams Publishing — Instructs beginning and advanced developers on taking advantage of the many environment guidelines required to built QT applications for KDE.