While Joomla is packed with features,its greatest quality is that it is extremely extensible,allowing any number of complex applications to be cleanly integrated. Forums,social networking profiles,job boards,and real estate listings are all examples of extensions developers have written for Joomla!. All of these can run off one Joomla! site,while only one database,template,and core need to be maintained.When you build an extension to Joomla!,it will inherit the look and feel of the overall site. Any type of program that can be coded in PHP is a potential component waiting to be written!