Darcs is a distributed revision control system by David Roundy that was designed to replace traditional centralized source control systems such as CVS and subversion. Two particular features in its design distinguish it from CVS. Each copy of the source tree acts as a full repository, allowing several different versions to be maintained in different locations. Patches are global to the repository and are subject under certain conditions to reordering, as governed by the project's "theory of patches".
The name is an acronym for David's Advanced Revision Control System, but is usually spelled lowercase (darcs), except at the beginning of sentences.
In basic usage, users get a copy of a repository, make any changes, record the changes, pull changes from other repositories, and finally pushorsend changes to other repositories. To start a new repository, users can init any directory.
Other repositories can be local directories, or accessed by SSHorHTTP protocols. Changes can be submitted by email in situations where the user lacks permission to write to another repository.
Many of its commands are interactive, allowing users to commit changes or pull specific files selectively. This feature is designed to encourage more specificity in patches. As a result of this interactivity, darcs has fewer distinct commands than many comparable revision control systems.
Bugs
Darcs has been criticized on the grounds of performance (see e.g. [1]).
^"One of the problems I had with the initial C++ darcs was that I had no unit testing code. Within two weeks of the first darcs record, I started using QuickCheck to test the patch functions, and the same day I fixed a bug that was discovered by QuickCheck. QuickCheck makes it very easy to define properties that functions must have, which are then tested with randomly generated data." From page 2 of David Roundy 2005.
Roundy, David (2005). "Darcs: distributed version management in Haskell". Proceedings of the 2005 ACM SIGPLAN workshop on Haskell Tallinn, Estonia. pp. 1–4. ISBN 1-59593-071-X; doi:10.1145/1088348.1088349. {{cite conference}}: Cite has empty unknown parameter: |coauthors= (help); Unknown parameter |booktitle= ignored (|book-title= suggested) (help)
