It is heavily inspired by Darcs, and is based on an alternative "theory of patches" that reportedly has much better worst-case performance characteristics. It

It is heavily inspired by Darcs, and is based on an alternative "theory of patches" that reportedly has much better worst-case performance characteristics. It is written in Rust, instead of Haskell, also contributing to better/more predictable performance. The Darcs folks are very aware and supportive of it, and last I heard, Darcs might add support for the Pijul patch format. This is an extremely exciting project. (speaking as a long time Darcs fan and passive onlooker who saw the Pijul presentation at rustconf)