Jena is a Java framework for building Semantic Web applications. It provides a programmatic environment for RDF, RDFS and OWL, SPARQL and includes a rule-based inference engine.
The OWL API is a Java API and reference implmentation for creating, manipulating and serialising OWL Ontologies. The latest version of the API is focused towards OWL 2
J. Völker, D. Vrandecic, and Y. Sure. Proceedings of the 4th International Semantic Web Conference (ISWC'05), volume 3729 of LNCS, page 716--731. Galway, Ireland, Springer, (November 2005)
J. Madhavan, P. Bernstein, A. Doan, and A. Halevy. ICDE '05: Proceedings of the 21st International Conference on Data Engineering (ICDE'05), page 57--68. Washington, DC, USA, IEEE Computer Society, (April 2005)
P. Visser, D. Jones, T. Bench-Capon, B. Díaz, and M. Shave. Proceedings of the International Conference on Database and Expert System Applications (DEXA-1999), volume 1677 of LNCS, page 668--677. Florence (Italy), Springer-Verlag, (1999)
B. Swartout, R. Patil, K. Knight, and T. Russ. Proceedings of the 10th. Knowledge Acquisition for Knowledge-Based Systems Workshop, Banff, Canada, (1996)
G. Stumme, and A. Maedche. Proceedings of the 17th International Conference on Artificial Intelligence (IJCAI-2001), page 225--230. Seattle (USA), (2001)
R. Pan, Z. Ding, Y. Yu, and Y. Peng. Proceedings of the 4th International Semantic Web Conference (ISWC-2004), volume 3729 of LNCS, page 563--577. Berline (Germany), Springer-Verlag, (2004)
B. Omelayenko, and D. Fensel. Proceedings of the Second Internacional Conference on Electronic Commerce and Web Technologies (ECWEB-2001), Munich (Germany), Springer-Verlag, (2001)
N. Noy, and M. Musen. Proceedings of the Workshop on Ontologies and Information Sharing at the Seventeenth International Joint Conference on Artificial Intelligence (IJCAI-2001), page 63--70. Seattle (USA), (2001)