From Fedora Project Wiki
riak
Riak, a scalable and reliable data store, is available in Fedora 15.
Riak is a Dynamo-inspired key/value store, written in Erlang, that scales predictably and easily. Riak also simplifies development by giving developers the ability to quickly prototype, test, and deploy their applications.
A truly fault-tolerant system, Riak has no single point of failure. No machines are special or central in Riak, so developers and operations professionals can decide exactly how fault-tolerant they want and need their applications to be.