Joomla! is an open source content management system platform for publishing content on the World Wide Web and intranets as well as a Model–view–controller (MVC) Web application framework. It is written in PHP, stores data in MySQL and includes features such as page caching, RSS feeds, printable versions of pages, news flashes, blogs, polls, search, and support for language internationalization.

The Joomla! package consists of many different parts, which allow modular extensions and integrations to be made easily. An example of such are extensions called Plugins. Plugins are background extensions that extend Joomla! or components with new functionality. There are over 3,000 extensions for Joomla! available via the Joomla Extensions Directory (JED).

In addition to Plugins, more comprehensive extensions are available. Components allow webmasters to perform such tasks as build a community by expanding user features, backup a website, translate content, create URLs that are more friendly to search engines and add shopping cart functionality for e-commerce website. Modules perform such tasks as displaying a calendar or allowing custom code like Google AdSense etc., to be inserted within the base Joomla! code.

Joomla! permits administrators to set global configuration parameters that affect every article. Every page conforms to these parameters by default, but a page can have its own setting for each parameter. For example, you can select to show or hide the article author or simply go with the global "show author" parameter.

More about joomla on:

• Joomla.org
• wikipedia.org (sources of this text)