Drupal a free and open-source content-management framework written in PHP and distributed under the GNU General Public License, provides a back-end framework for at least 2.2% of all Web sites worldwide – ranging from personal blogs to corporate, political, and government sites. Systems also use Drupal for knowledge management and for business collaboration. The standard release of Drupal, known as Drupal core, contains basic features common to content-management systems. These include user account registration and maintenance, menu management, RSS feeds, taxonomy, page layout customization, and system administration. The Drupal core installation can serve as a simple Web site, a single- or multi-user blog, an Internet forum, or a community Web site providing for user-generated content. “The Drupal Overview”, a feature of the project web site, describes it as a content management framework. Drupal also describes itself  as a Web application framework, as it meets the generally accepted feature requirements for such frameworks.