Sesame is an open source Java framework for storage and querying of RDF data. The framework is fully extensible and configurable with respect to storage mechanisms, inferencers, RDF file formats, query result formats and query languages. Sesame offers a JBDC-like user API, streamlined system APIs and a RESTful HTTP interface supporting the SPARQL Protocol for RDF.

Of course, a framework isn't very useful without implementations of the various APIs. Out of the box, Sesame supports SPARQL and [SeRQL] querying, a memory-based, a disk-based and an RDBMS-based RDF store and RDF Schema inferencers. It also supports most popular RDF file formats and query result formats. Various extensions are available or are being worked at elsewhere.

Sesame 2.0 documentation
Developing Sesame