Best Web Design Pahang, Joomla is an award-winning content management system (CMS), which enables you to build Web sites and powerful online applications. Joomla is an award-winning content management system (CMS), which enables you to build Web sites and powerful online applications. Many aspects, including its ease-of-use and extensibility, have made Joomla the most popular Web site software available. Best of all, Joomla is an open source solution that is freely available to everyone. A content management system is software that keeps track of every piece of content on your Web site, much like your local public library keeps track of books and stores them.