Arakoon - a distributed consistent key-value store, by Nicolas Trangez.

Arakoon is a simple consistent distributed key value store. Technically, it’s an OCaml implementation of Multi-Paxos on top of Tokyo Cabinet, using Ocsigen’s Light Weight Thread (Lwt) library for managing concurrency. Arakoon offers guaranteed consistency (as opposed to even- tual consistency), range queries, transactions, server side extensions and shards. It’s robust and fits the niche of small but important data items quite well.