What is Drupal?

• Free Open Source Software
  Drupal is released under GNU General Public Licence. That means the source code behind the software is freely available and any modifications to it must be released under a similar licence. To the end user, this means that you can be sure the system will remain free and continue to be supported by a community of developers who want it to remain that way.
• Modular
  Drupal is all modular so no two Drupal sites will be the same, since they will use different combinations of modules in different ways. Key parts of the functionality on offer is part of the core distribution - user management, content management, content classification, content syndication, templating and localisation. But this can be extended with hundreds of other modules such as forums, calendars, private messaging, profile extensions, views, polls, image galleries, multilingual support and integration with CiviCRM to name but a few!
• A CMS construction kit
  Drupal is not just a CMS, it's rather a platform on which to build your own custom site.
• Powerful
  Choosing the right combination of modules to rapidly deploy advanced functionality, combined with the hugely flexible user management system and its taxonomy system of content classification makes Drupal a hugely powerful system. Due to its modular nature, you can choose to harness whichever parts of that power, suit your purposes.
• Accessible
  Drupal uses standards-compliant methods such as XHTML, separation of content and layout through CSS and
  clean URLs to make sites accessible and to improve search engine ranking.