Semantic MediaWiki
Introduction
“Semantic MediaWiki (SMW) is an extension of Mediawiki – the wiki application best known for powering Wikipedia – that helps to search, organise, tag, browse, evaluate, and share the wiki's content. While traditional wikis contain only text which computers can neither understand nor evaluate, SMW adds semantic annotations that allow a wiki to function as a collaborative database. Semantic MediaWiki was first released in 2005, and currently has over ten developers, and is in use on hundreds of sites. In addition, a large number of related extensions have been created that extend the ability to edit, display and browse through the data stored by SMW: the term "Semantic MediaWiki" is sometimes used to refer to this entire family of extensions. Semantic MediaWiki has been funded in part by projects of the Framework Programmes (FP) of the European Union, SEKT and ACTIVE and by project Halo.” (Introduction to Semantic MediaWiki, retrieved 12:00, 24 August 2011 (CEST))
According to Semantic MediaWiki, “is currently in active use in hundreds of sites, in many languages, around the world, including Fortune 500 companies, biomedical projects, government agencies and consumer directories”.