MySQL

MySQL is a relational database management system (RDBMS) which has more than 11 million installations. The program runs as a server providing multi-user access to a number of databases. MySQL is popular for web applications and acts as the database component of the LAMP, BAMP, MAMP, and WAMP platforms (Linux/BSD/Mac/Windows-Apache-MySQL-PHP/Perl/Python), and for open-source bug tracking tools like Bugzilla. Its popularity for use with web applications is closely tied to the popularity of PHP and Ruby on Rails, which are often combined with MySQL. PHP and MySQL are essential components for running popular content management systems such as Drupal, e107, Joomla!, WordPress and some BitTorrent trackers. Wikipedia runs on MediaWiki software, which is written in PHP and uses a MySQL database.
Projects: MobilCity, ShareLocator, turners75, GNO, SpryCase, RePay, OmGTU IVT Wiki, GamblingCompliance, Querdak, Nelsok.