Joomla! is an open-source CMS written in PHP and powered by an MVC-oriented framework. Please note that version 2.5 is no longer a supported release and it's highly recommended to upgrade to the latest version. Joomla! questions about programming and administration are best asked on https://joomla.stackexchange.com
Joomla! 2.5
Joomla! is an open-source CMS written in PHP and powered by an MVC-oriented framework. Thousands of extensions are available and can be installed through the admin interface.
Version 2.5 has ended it's life on December 31st, 2014 and it's highly recommended to upgrade to the latest version.