Jena is a Java framework for building Semantic Web applications. It provides a extensive Java libraries for helping developers develop code that handles RDF, RDFS, RDFa, OWL and SPARQL in line with published W3C recommendations. Jena includes a rule-based inference engine to perform reasoning based on OWL and RDFS ontologies, and a variety of storage strategies to store RDF triples in memory or on disk.
Jena was originally developed by researchers in HP Labs, starting in Bristol, UK, in 2000. Jena has always been an open-source project, and has been extensively used in a wide variety of semantic web applications and demonstrators. In 2009, HP decided to refocus development activity away from direct support of development of Jena, though remaining supportive of the project's aims. The project team successfully applied to have Jena adopted by the Apache Software Foundation in November 2010 (see the vote result).
Jena entered incubation with the Apache in November 2010, and graduated as a top-level project in April 2012.
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