XGR (XML Data Grid) and BabelPeers are both data management systems based on distributed hash tables (DHT) that use the Pastry DHT to store data and meta data. XGR is based on the XML data model; BabelPeers uses the Resource Description Framework (RDF) for its data. XGR and BabelPeers have different but complementary functionality. On the one hand, XGR focuses on document-based storage of XML data and publish/subscribe mechanisms, on the other hand, BabelPeers focuses on query strategies that combine pieces of information originating from various sources and provides reasoning about the information. Thus it is valuable to research how the two concepts can be merged to get the best of both worlds.1