MediaWiki

MediaWiki derives from the word "wiki", which is a web application designed to allow multiple authors to create, remove, and edit web page content using a web browser. The multiple author capacity makes them effective tools for mass collaborative authoring. One of the best-known is the online encyclopedia called Wikipedia. Also, the term refers to the collaborative software used to create such a website, known as Wiki Software, which is usually implemented as a script that runs on a web server with the wiki content stored in a relational database management system such as MySQL.

When a user submits an edit to a page, MediaWiki writes it to the database, but without deleting the previous versions of the page. This allows the user and/or administrator to easily go back and refer to the older content, incase spamming or vandalism has occurred.