This book is designed for people interested in learning how to program the X Window System and assumes some basic knowledge on how to use a computer, how to setup and useThe X Window System, how to use a compiler, and how to write a program in theC programming language. This book is open work, so if you find any problems with terms or concepts, you can contribute an explanation to it. Feel free to participate; you are welcome to do so.
TheX Window System (orX andX11 for short) is a server application that provides basic functions for displaying graphics and gathering user input transparently, either locally or over a network. X distributes user input to and accepts output requests from applications through the X Window System protocol.
X does not mandate the visual appearance and interface of applications, choosing instead to allow applications to use whatever visual style and interface is desired. As a result, different applications may present radically different interfaces.