For programmers developing interactive applications for the X Window System using the Motif user-interface toolkit. This completely updated and revised version of the best-selling First Edition describes how to develop interactive applications for the X Window System using the Motif user interface toolkit. The X Window System is the industry-standard software system that allows programmers to develop portable graphical user interfaces. Motif is a high-level user-interface toolkit that makes it easier to write applications that use the X Window System.