| Mulgara Semantic Store | |
| Latest Release Version: | 2.1.13 |
| Programming Language: | Java |
| Genre: | Semantic Web |
| License: | Open Software License |
Mulgara is a triplestore and fork of the original Kowari project. It is open-source, scalable, and transaction-safe.[1] Mulgara instances can be queried via the iTQL query language and the SPARQL query language.[2]
Kowari was first made available for download in beta form on October 26, 2003.[3] In April 2004,[4] Tucana Technologies Inc demonstrated the Tucana Knowledge Server (TKS), a proprietary RDF database relying on Kowari as the basis. A steady number of releases occurred throughout 2004, including version 1.0.5 and 1.1 pre-release. The development of TKS stalled due to difficulties with funding at the end of 2004,[5] while the development of Kowari continued on.[6]
In September 2005, Tucana was bought by Northrop Grumman.[7] In January 2006, Northrop Grumman threatened a Kowari developer with legal action if he released any new version of Kowari.[8] As a consequence, Kowari was forked in July 2006. It was renamed to Mulgara as Northrop Grumman owned the Kowari trademark. All development on Kowari has stopped[9] and the community moved to Mulgara. The legal cloud surrounding Kowari was eventually resolved,[10] one of the outcomes was the adoption of the Open Software License 3.0. Since 2008 all new code is being licensed with the Apache 2.0 License.[2]
Since 2006 Mulgara 1.0.0 has been released, significant changes to the transaction architecture was made to support JTA, SPARQL support, a Jena API, and integration with Sesame has been added. As of January 10, 2012 the latest version is 2.1.13.[11]
Mulgara is not based on a relational database due to the large numbers of table joins encountered by relational systems when dealing with metadata. Instead, Mulgara is a completely new database optimized for metadata management. Mulgara models hold metadata in the form of short subject-predicate-object statements, much like the W3C's Resource Description Framework (RDF) standard. Metadata may be imported into or exported from Mulgara in RDF or Notation 3 form.[1]