Prophet is a lightweight schemaless database designed for peer to peer replication and disconnected operation. Prophet keeps a full copy of your data and (history) on your laptop, desktop or server. Prophet syncs when you want it to, so you can use Prophet-backed applications whether or not you have network.
SD (Simple Defects) is a peer-to-peer issue tracking system built on top of Prophet. In addition to being a full-fledged distributed bug tracker, SD can also bidirectionally sync with your RT, Hiveminder, Trac, GitHub or Google Code issue tracker.