Joomla! is an Open Source Content Management System (CMS) that consists of the core framework for 2,6% websites around the net. Joomla! is one of the many examples that the Web 2.0 offers, where libraries of programming is shared and compiled through a worldwide community of programmers. Joomla! today is used to create sophisticated websites that can be multi-lingual, extensible, flexible, secure, accessible, and more importantly self maintainable. In this article, we will present the fundamentals of Joomla!, an explanation how Joomla! came about and the basic principles of its Content Management System.