The make utility automatically determines which pieces of a large program need to be recompiled, and issues commands to recompile them. This manual describes GNU make, which was implemented by Richard Stallman and Roland McGrath. This book is available as a free PDF from gnu.org. The Make program is indispensable to maintainers of free software systems. The GNU Make manual, written by the program's original authors, is the definitive tutorial. It also includes an introductory chapter for novice users. The Make utility automates the process of compilation; it is especially useful when the source files of large programs change. It is a small program with a lot of power. This book will show you: How to write your own makefiles Make's rule syntax and how to write your own rules How the Make utility can be configured to automatically put binary and source files in the right places. How to use make to create archive files automatically Define, set and use Make's variables How Make uses targets so that you can broaden or narrow Make's recompilation efforts on demand. And much more! This manual provides a complete explanation of Make, both the basics and extended features.