Jena

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.

Jena is open source and grown out of work with the HP Labs Semantic Web Programme.

The Jena Framework includes:

A RDF API

Reading and writing RDF in RDF/XML, N3 and N-Triples

An OWL API

In-memory and persistent storage

SPARQL query engine