Drupal
From CSS Discuss
Drupal is an open-source content management system. Drupal is a CMS written in the PHP language, and allows the webmaster of the site using Drupal to customize the particular site without having to know much about programming. Drupal requires a database to store content and control different settings, but uses different modules to control different functions of a web site.
Drupal is well-known around the open-source design and webmaster world. Using CSS, it is known as one of the most Css Friendly Cms.
For more information, see Drupal Design.
