GridVine (2004 – 2008)
GridVine is an RDF Peer Data Management Systems (PDMS) based on a peer-to-peer access structure. Built following the principle of data independence, it separates a logical layer — where data, schemas and schema mappings are managed — from a physical layer consisting of a structured peer-to-peer network supporting decentralized indexing, key load-balancing and efficient routing. Our system is totally decentralized, yet it fosters semantic interoperability through pair-wise schema mappings and query reformulation. In GridVine, heterogeneous but semantically related information sources can all be queried transparently using iterative query reformulation.