Some say that the Drupal platform is the best platform out there. As I wouldn't dare disagree, at the end I feel the correct platform to use always depends on your specific business plan and needs. In other words, we must use the right tool for the job.
Drupal and Joomla have many elements in common, so in terms of scalability and flexibility the Drupal platform matches Joomla well. Where Drupal excels is with its ability to define and administer user groups in a non-linear fashion, where Joomla at the moment has linear user groups (to change in Joomla 1.6 they say). Drupal falls short a bit in ease of use and intuitive operation, which are hallmark features of WordPress and Joomla. Drupal has unlimited categorization ability (known as taxonomy) and the endless modules contributed to the community allow for endless combinations of features.
Drupal would be the choice platform for business models needing advanced community features, multiple user groups, detailed organization, or if you need custom scripts integrated into the system. Drupal is a perfect candidate for Intranet applications or any business plan that needs to have different user groups with their own specific set of permissions. It also has a very supportive community with support for the novice and advanced users alike.
Who uses Drupal?
Drupal is also perhaps a bit more high maintenance of a platform, however it is a testament to its vast capabilities.
Our services with Drupal include.