What is Joomla?
Joomla! is a free and open source content management system (CMS) for publishing content on the World Wide Web and intranets. It comprises a model–view–controller (MVC) Web application framework that can also be used independently.
Joomla! is written in PHP, uses object-oriented programming (OOP) techniques and software design patterns, stores data in a MySQL database, and includes features such as page caching, RSS feeds, printable versions of pages, news flashes, blogs, polls, search, and support for language internationalization.
Within its first year of release, Joomla had been downloaded 2.5 million times. Between March 2007 and February 2011 there had been more than 21 million downloads. There are over 7,400 free and commercial extensions available from the official Joomla! Extension Directory and more available from other sources.
The latest version is Joomla 1.6 and this is the one we will be dealing with.