MediaWiki is a web-based wiki software application used by all projects of the Wikimedia Foundation, all Wikia wikis, and many other wikis. Originally developed to serve the needs of the free content Wikipedia encyclopedia, today it has also been deployed by companies for internal knowledge management, and as a content management system. Notably, Novell uses it to operate several of its high-traffic websites.

MediaWiki is written in the PHP programming language, and can use either the MySQL and PostgreSQL relational database management systems or SQLite.