Also known as gnu-arch. It is an implementation of arch in C, by Tom
Lord.

A modern replacement for CVS, specifically designed for the distributed
development needs of open source projects. It has uniquely good support
for development on branches (especially good merging tools),
distributed repositories (every developer can have branches in their
own repository), changeset-oriented project management (arch commits
changes to multiple files at once), and, of course, file and directory
renaming.

You might also want to install a GUI for tla - archway or web based
browser - archzoom.