Drupal

is a Content Management System (CMS) and framework that was originally designed by the Belgian Dries Buytaert
It is written in PHP and uses MySQL or PostgreSQL as a database (Oracle and SQLite for development in Drupal 7)
With Drupal can be, as with other content management systems, content to the Internet and put process

Drupal is different from other CMS in particular through the implementation of approaches of social software and it supports the building of communities, want to work together on content and to exchange information about issues
It supports a differentiated roles and rights system