Drupal is a completely free, open source content management system. It enables one to create, update and manage a website without requiring a lot of technical know-how. Drupal's many features and add-ons allow it to be used for a variety of website needs; perhaps for marketing or commerce, internal communications, informational websites, or for social networking purposes.
Drupal uses a point-and-click interface to let you add pages, menus, rich-media and much more to your website easily. It enforces security, so you can apply access permissions to different kinds of users. As your website grows, it's easy to add custom features from the thousands of free modules available for download from http://drupal.org. Drupal is universally regarded as one of the best website frameworks available and is rapidly gaining adoption all over the globe.