Michael J. Ross writes "Every major content management system (CMS) offers considerable functionality for building Web sites out of the box. But to get the most out of any CMS, its functionality must be extended through the addition of modules, most of which are created by third-party developers. For instance, a given CMS may need to be supplemented by an e-commerce module in order to use that CMS for building an online store. Joomla, one of the most widely used CMSs, is no exception. Web developers interested in creating their own Joomla extensions can read Learning Joomla! 1.5 Extension Development, authored by Joseph LeBlanc." Read below for the rest of Michael's review.