as a directed acyclic graph of commit objects pointing to snapshots of content, with all data saved in it's own custom content addressable filesystem by the SHA-1 checksum hash of each objects data. Branches are simply pointers into this directed graph of commits, identifying entry points that designate the latest work on that branch, allowing Git to traverse the pointers, determining a coherent history. This makes branching cheap and easy, and merging simple, encouraging non-linear development styles and frictionless context switching while facilitating distributed development, cryptographic integrity and late decision making. Nearly all commands run locally with no network latency overhead and it is implemented mainly in C, making it incredibly fast and efficient even for very large projects. There are several large open source projects using it, not to mention the 100,000 open source repositories maintained by the 80,000 developers on GitHub alone. https://gist.github.com/schacon/111475