Irmin, the database that never forgets

Irmin is a distributed database with built-in snapshot, branch and revert mechanisms. It is designed to use a large variety of backends, although it is optimized for append-only store.

Irmin is written in pure OCaml. It can thus be compiled to Javascript -- and run in the browsers; or into a MirageOS unikernel -- and run directly on top of Xen.