Monotone is a distributed version control tool. It can help automate
many tedious and error-prone tasks in group software development.

    * Store multiple versions of files you are working on efficiently.
    * Transmit changes to files between you and your colleagues.
    * Merge changes you make with those your colleagues make.
    * Make notes about your opinion of the quality of versions of files.
    * Make decisions about using or ignoring versions, depending on
       the notes you receive from others.

WWW: http://www.venge.net/monotone/