Drupal is a free, open-source web development platform for online content and user communities. Drupal powers some of the busiest sites on the web, and can be adapted to virtually any visual design. Drupal runs over a million sites, including WhiteHouse.gov, World Economic Forum, Stanford University, and Examiner.com.
It is released as open-source software under the GNU Public License. It is completely free to download, use, and modify i.e.There are no purchase, license, or maintenance fees.
Drupal’s default installation is a database-backed web platform with file maintenance tools and a high level of security. It is a multi-user system. You control their access levels, and can also assign “roles” for multiple permission levels.
Drupal both hosts and promotes your content. It’s built-in features also give search engines what they want, improving your web impact automatically.