Semantic MediaWiki

Semantic MediaWiki (SMW) is a free, open-source extension to MediaWiki – the wiki software that powers Wikipedia – that lets you store and query data within the wiki's pages.

Semantic MediaWiki is also a full-fledged framework, in conjunction with many spinoff extensions, that can turn a wiki into a powerful and flexible “collaborative database”. All data created within SMW can easily be published via the Semantic Web, allowing other systems to use this data seamlessly.