Drupal is an open source web content management framework. The free software allows users to design their custom CMS. Many alternative content management systems, including commercial ones, are limited by their built-in functionality in the ways to deal with content.

The Drupal CMS changes this. By combining the use of the Drupal framework with three popular extensions: Views, to create custom database queries of content, the Content Construction Kit (CCK), to create custom forms for adding content to the database (with unlimited custom fields and references), and Contemplate, a tool to create custom layouts for different content types.

There exist many addtional core extentions, thousands maintainted by volunteers of the open source community. However with these three modules, Views, CCK and Contemplate, it is already possible to create any website in the world. Morningtime has many years of experiences in working with Drupal. This website, morningtime.com, was also built with Drupal.

Even WhiteHouse.gov will be built on drupal:
http://personaldemocracy.com/node/15131