CVS is a version control system. Using it, you can record the history of your source files.
CVS started out as a bunch of shell scripts written by Dick Grune, posted to the newsgroup comp.sources.unix in the volume 6 release of July, 1986. While no actual code from these shell scripts is present in the current version of CVS much of the CVS conflict resolution algorithms come from them.
In April, 1989, Brian Berliner designed and coded CVS. Jeff Polk later helped Brian with the design of the CVS module and vendor branch support.
You can get CVS in a variety of ways, including free download from the Internet.
For more information on downloading CVS and other CVS topics, see: