MediaWiki is a free Open Source software wiki package originally written for Wikipedia, licensed under the GNU General Public License (GPL).

MediaWiki is an extremely powerful, scalable software and a feature-rich wiki implementation, that uses PHP to process and display data stored in its MySQL database.

MediaWiki is a web-based wiki software application used by all projects of the Wikimedia Foundation, all wikis hosted by Wikia, and many other wikis, including some of the largest and most popular ones. 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.