Summary: The Linux Kernel Module Programming Guide is a free book that provides a comprehensive guide to programming kernel modules in Linux. The book covers topics such as headers, examples, character device drivers, the /proc file system, sysfs, system calls, interrupt handlers, and common pitfalls. The book is distributed under the Open Software License, version 3.0, and can be reproduced and modified for personal or commercial use as long as the copyright notice remains intact. The book encourages contributions and updates to be made available to the document maintainer, Jim Huang.