he LUPOSDATE SPARQL system supports various approaches to manage RDF data and process SPARQL queries: Index, RDF3X, Stream, Jena and Sesame. Jena [21] and Sesame [3] refer to third-party SPARQL engines. Index is our in-memory Engine presented in [6]. Stream is our stream-based implementation (see [10]). RDF3X is a re-implementation of [14], but is further enhanced with additional optimization strategies.
J. Broekstra, A. Kampman, and F. van Harmelen. Proceedings of the first International Semantic Web
Conference (ISWC 2002), 2342, page 54--68. Sardinia, Italy, Springer Verlag, Heidelberg Germany, (June 2002)See also http://www.openrdf.org/.