CVS
A Concurrent Versions System (CVS) repository is a source control system intended to allow a team or group to work on the same files and projects simultaneously, and to revert file and project states back to previous versions.
Once projects are placed on the CVS repository, they can be checked out (imported) by anyone with access to that repository. CVS repository connections allow you to import projects from your repository to your workspace, which you can make and upload changes to.
CVS functionality can be accessed from the CVS Repository Exploring Perspective, accessed by going to Window | Open Perspective | Other | CVS Repository Exploring.