A version control system (VCS) is a system for managing changes to documents, programs, and other information. They are commonly used for program development done by a team of people working independently.
CVS (1.11.22) [Helix] [Biowulf]
CVS is a version control system, an important component of Source Configuration Management (SCM).
Subversion (1.6.11) [Helix] [Biowulf]
Subversion is an open source version control system.
git (1.7.4) [Helix] [Biowulf]
Git is a free & open source, distributed version control system designed to handle everything from small to very large projects with speed and efficiency.
mercurial (1.6.4) [Helix] [Biowulf]
Mercurial is a free, distributed source control management tool. It efficiently handles projects of any size and offers an easy and intuitive interface.