What is Joomla?
Joomla is an award-winning content management system (CMS) that enables us to build Web sites and powerful online applications. Many aspects and features, including its ease-of-use and extensibility, have made Joomla a very popular Web site software available. Best of all, Joomla is an open source solution that is freely available to anyone thereby making it popular.
What is a content management system or CMS?
A content management system is software that keeps track of every piece of content on your Web site. Content can be simple text, photos, music, video, documents and such. A major advantage of using a CMS is that it simplifies the management of content and requires almost no special skill or technical knowledge to manage.
More examples of companies using Joomla can be found in the Joomla Community Site Showcase.