This manual describes how to use CVS, a powerful version control system. CVS tracks changes to source code and documents, allowing previous versions to be recovered at any time. Releases and branches can be tagged with symbolic names to record sets of files for permanent reference. CVS supports many advanced features including branching and merging, export and patch file generation, and tracking of third party sources (vendor branches). CVS can increase the efficiency of development teams by allowing concurrent development. CVS uses a conflict detection algorithm to allow multiple developers to work on the same files simultaneously. CVS is free software, distributed under the terms of the GNU General Public License (GPL). CVS runs on GNU (GNU/Linux) and Unix systems. CVS client software is also available for Microsoft Windows. This is a printed version of the official CVS manual. All the money raised from the sale of this book supports free software development and documentation.