James Tauber and Daniel Krech developed this toolkit for working with Resource Description Framework (RDF) data. The tools include an RDF parser and serializer, RDF database, an API for queries, a convenient user interface, and a web server that provides an interface for viewing and editing RDF in the database. A number of sample applications built on top of Redfoot are available as well.
More information is available at http://redfoot.sourceforge.net/, as well as the implementation and complete documentation.