Joomla! is a powerful  Open Source PHP CMS (Content Management System) for building professional web sites easily. It is often the system of choice for small business or home users who want a professional looking site that's simple to deploy and use. It can deliver a robust enterprise-level Web site as well, empowered by endless extensibility for your bespoke publishing needs.

Joomla! is different from the normal models for content management software. For a start, it's not complicated. Joomla! has been developed for everybody, and anybody can develop it further.

Similarly to the Firefox browser, the core system can be extended via easily installable add-ons authored by the developer community. The comprehensive internationalization of Joomla! 1.5.x supports right to left languages (e.g. Hebrew or Arab) and extended character sets. Dozens of language packs can be separately downloaded.

Requirements:
-PHP 5.2 or Higher
-MySQL 4.1.0 or Higher     
-Apache(with mod_mysql, mod_xml,and mod_zlib) 2.0 or Higher          
-Microsoft IIS    7