|Virtuoso Universal Server Open Source Edition|
|Last release:||6.1.5 (2012-03-16)|
Virtuoso Universal Server is a middleware and database engine hybrid that combines the functionality of a traditional RDBMS, ORDBMS, virtual database, Resource Description Framework (RDF), XML, free-text, Web Application Server, and File Server, into a single server product offering. Rather than have dedicated servers for each of the aforementioned functionality realms, Virtuoso is a "universal server"; it enables a single multi-threaded server process that implements multiple protocols. The open source edition of Virtuoso Universal Server is also known as OpenLink Virtuoso.