Mercurial is a fast, lightweight source control management system designed for
efficient handling of very large distributed projects. Features include:

    * O(1) delta-compressed file storage and retrieval scheme
    * Complete cross-indexing of file and changesets for efficient exploration
      of project history
    * Robust SHA1-based integrity checking and append-only storage model
    * Decentralized development model with arbitrary merging between trees
    * High-speed HTTP-based network merge protocol
    * Easy-to-use command-line interface
    * Integrated stand-alone web interface
    * Small Python codebase
    * GPL license

WWW: https://www.mercurial-scm.org/