Drupal is a free and open-source web content management system (CMS) written in PHP and distributed under the GNU General Public License. Drupal provides an open-source back-end framework for at least 14% of the top 10,000 websites worldwide and 1.2% of the top 10 million websites—ranging from personal blogs to corporate, political, and government sites. Drupal can also be used for knowledge management and for business collaboration.

PHP is a general-purpose scripting language geared towards web development. It was originally created by Danish-Canadian programmer Rasmus Lerdorf in 1993 and released in 1995. The PHP reference implementation is now produced by the PHP Group. PHP was originally an abbreviation of Personal Home Page, but it now stands for the recursive initialism PHP: Hypertext Preprocessor.