Drupal is a content management system (CMS) created initially by Dries Buytaert from the Netherlands. The project started in the year 2000. The Drupal project is open source and has an active user community approaching 100,000 user in the summer of 2006. Drupal allows those with just a smattering of html, css, php, and mysql knowledge to create powerful, interactive, easily updatable web sites for a small fraction of the cost of doing so just a few years ago.
The Drupal community is highly collaborative and special efforts have been made by associated groups to create models and installation packages which specifically support small and not-for-profit organizations. CiviCRM is one project that is supporting Drupal and sponsoring compatible modules to help not-for-profit organizations keep better track of their constituents. Drupal’s core program is extensible via contributed modules and a well-written clear set of APIs.The number of modules available for Drupal is growing daily More information about Drupal can be found at http://drupal.org/