PeerDB

"PeerDB is a peer-to-peer (P2P) distributed data sharing system. It provides full-fledged data management system that supports fine-grain content-based search, combines the power of mobile agents into P2P systems to perform operations at peers' sites and is self-configurable." (http://thothzone.blogspot.com/2006/07/p2p-buzz-to-biz.html)