Drupal

Drupal is an open source content management system used to publish content to web applications. One of the best features of Drupal is that it is modularly built and extendable, so new features can easily be added by developers. Drupal modules are built using Object-oriented Programming in PHP and range in size from a single PHP class to branches of submodules with hundreds of classes each. Thousands of modules have been contributed by the Drupal community on drupal.org, and additional features can be added through custom modules.