Drupal is an answer to Wordpress Joomla in terms of speed and simplicity and is worth a look when trying to decide between the two CMS's. What about security ?? Drupal has a good reputation for security. The advantage of Drupal in this scenario is the ability to export the entire Drupal site at anytime so you can load it up on your own Drupal installation should the future ever require it. Drupal runs over a million sites, including WhiteHouse.gov, World Economic Forum, Stanford University, and Examiner.com. Demand for Drupal talent is growing, and opportunities abound for developers, designers and artists, and related disciplines such as database and system administration. There are some very solid technical, organizational and economic reasons why Drupal makes seriously good sense, especially at the enterprise level.
Carmen from Drupal Web Services