Before taking advantage of the PEAR installer, it is important to set up a source control system. There are many fine commercial software programs that can be used to perform source control, including Perforce and Visual SourceSafe, but we will focus on the tried and true, free open-source revision control systems: CVS and Subversion.
CVS (Concurrent Versioning System) is one of the oldest source-control products, and is based on the even older RCS (Revision Control System) source control program. CVS implements its source control by using a client-server model. The server contains the final code, organized into directories and files. However, on the server, each file actually contains a full revision history of that file. On the client end, users check out a local sandbox—a copy of the server code, which can then be developed independently of other developers. When the code is ready to be committed to the server, the user sends a special...