Drupal is an open source content management platform.

Equipped with a powerful blend of features, Drupal supports a variety of websites ranging from personal weblogs to large community-driven websites.

Drupal is a free software package that allows an individual or a community of users to easily publish, manage and organize a wide variety of content on a website. Tens of thousands of people and organizations are using Drupal to power scores of different web sites, including

• Community web portals
• Discussion sites
• Corporate web sites
• Intranet applications
• Personal web sites or blogs
• Aficionado sites
• E-commerce applications
• Resource directories
• Social Networking sites

Drupal is ready to go from the moment you download it. It even has an easy-to-use web installer! The built-in functionality, combined with dozens of freely available add-on modules, will enable features such as:

• Content Management Systems
• Blogs
• Collaborative authoring environments
• Forums
• Peer-to-peer networking
• Newsletters
• Podcasting
• Picture galleries
• File uploads and downloads

and much more.

Drupal is open-source software distributed under the GPL ("GNU General Public License") and is maintained and developed by a community of thousands of users and developers.

See the Wikipedia page on Drupal for more information.