Joomla (/ˈdʒuːm.lɑː/), also spelled Joomla! (with an exclamation mark) and sometimes abbreviated as J!, is a free and open-source content management system (CMS) for publishing web content on websites. Web content applications include discussion forums, photo galleries, e-Commerce and user communities and numerous other web-based applications. Joomla is developed by a community of volunteers supported with the legal, organisational and financial resources of Open Source Matters, Inc.

Joomla is written in PHP, uses object-oriented programming techniques and software design patterns, and stores data in a Structured Query Language (MySQL) database.[4] It has a software dependency on the Symfony PHP framework. Joomla includes features such as page caching, RSS feeds, blogs, search, and support for language internationalisation. It is built on a model–view–controller web application framework that can be used independently of the CMS.