Darcs - Cross-platform version control system, like git, mercurial or svn but with a very different approach: focus on changes rather than snapshots. (Source Code) GPL-2.0Haskell
Fossil - Distributed version control with built-in wiki and bug tracking. (Source Code) BSD-2-ClauseC
Git - Distributed revision control and source code management (SCM) with an emphasis on speed. (Source Code) GPL-2.0C
Mercurial - Distributed source control management tool. (Source Code) GPL-2.0Python/C/Rust