It seams that no Joomla related blog is complete without an obligatory comparison between Joomla and Drupal.
As I've never used Drupal, and have no intention of learning it, I'm not really in a position to do a comparison.
And even if I did I am sure it would be unfairly biased as my years of experience with Joomla is bound to influence my conclusions and decisions.
So rather than attempt to produce an unbalanced report here is an excellent one from 3 students.
"A comparative study of content management systems was made between Joomla and Drupal. The goal of this comparative study is to find the better CMS of the two according to various selected criteria. The criteria includes installation, platform support, browser support, modules and extensions, documentation, support, user management, multimedia integration, content creation and searching. While testing, Joomla out performs Drupal when comparing user interface, offering a more simple interaction between the user and the software, and offering a larger database of modules; however, Drupal out performs Joomla when comparing documentation and user management. Each of these CMS offers great management tools; however, still lack development in certain criteria."