One of the most secure CMS
Launched in year 2001 as a modest Content Management System or CMS for dynamic websites, Drupal has become in a few years a reference to create website of all types, from small blogs to institutional websites, the most important website that uses this application is the official site of the White House.
The main advantage in Drupal is the security, since the beginning Drupal was developed to provide a safe environment for publishers and webmasters, security flaws have been minimal compared to similar applications like Joomla o WordPress.
While the leaning curve of Drupal is more complicated compared to other CMS, once you dominate the first steps you will be able to create virtually any type of website because of its flexibility and quantity of available modules that provide additional functionalities.