The major support tools for supporting the development process are CVS, CVSup, Perforce, GNATS, Mailman and OpenSSH. Except for CVSup, these are externally developed tools. These tools are commonly used in the open source world.
Subversion (“SVN”) is a system to handle multiple versions of text files and tracking who committed what changes and why. A project lives within a “repository” and different versions are considered different “branches”.