His main research interests include Semantic Web and Peer-to-Peer information management systems, semistructured and XML/RDF data models and query languages as well as description and composition languages for e-services. He has published over 60 articles in international conferences and journals and received the 2004 SIGMOD Test of Time Award and the Best Paper Award at the 2nd and 6th International Semantic Web Conference in 2003 and 2007. http://www.ics.forth.gr/~christop/