[fizx]

For projects with similar goals, see also Twitter's Gizzard (abandoned) and LinkedIn's Voldemort.

[anonfunction]

Add Mashape's Astronode to the list: https://github.com/Mashape/Astronode-Broadcaster

[wowmsi]

Also Riak. However, one interesting aspect of Dynomite seems to be offer default support for clustering across multiple data centers with pluggable stores.

[darkr]

Riak (enterprise version) does that, and has pluggable stores (albeit limited to in-memory, bitcask + eleveldb)