darcs: darcs - an advanced revision control system
darcs: 
darcs: Distributed: Every user has access to the full command set, removing
darcs: boundaries between server and client or committer and non-committers.
darcs: Interactive: Darcs is easy to learn and efficient to use because it
darcs: asks you questions in response to simple commands, giving you choices
darcs: in your work flow. You can choose to record one change in a file,
darcs: while ignoring another. As you update from upstream, you can review
darcs: each patch name, even the full "diff" for interesting patches.
darcs: Smart: Originally developed by physicist David Roundy, darcs is based
darcs: on a unique algebra of patches.