Apache Jena
Jena is an open source java-based software development library for semantic web and linked data systems. Originally developed at Hewlett Packard Laboratories, it was first released in August 2000. Jena2 was released in 2004, to coincide with the adoption of the RDF and OWL standards. Jena tracked SPARQL 1.0 as it progressed to standardization in January 2008, and now provides a SPARQL 1.1 implementation.
Jena is widely used, with over 200,000 downloads. It is used by large corporations; by SME’s; by linked data tool vendors; and by academics. It has active user and development discussion lists (jena-users@incubator.apache.org and jena-dev@incubator.apache.org) .
Jena is currently undergoing incubation at The Apache Software Foundation (ASF), and is now known as Apache Jena.
More information about Jena, and download instructions, are found on the Apache Jena website.