MediaWiki is a free and open-source wiki application. Originally developed by Magnus Manske and improved by Lee Daniel Crocker, it runs on many websites, including Wikipedia, Wiktionary and Wikimedia Commons. It is written in the PHP programming language and stores the contents into a database. Like WordPress, which is based on a similar licensing & architecture, it has become the dominant software in its category. It has also been deployed by some companies as an internal knowledge management system, and some educators have assigned students to use MediaWiki for collaborative group projects.