wordpress

WordPress is a well architectured personal publishing system built on PHP and MySQL foundation. WordPress is licensed under the GPL and has been developed since its concept in 2001. It is a mature and stable product. By focusing on web standards and user experience create a tool different from anything else out there.

alfresco

Alfresco is an Open Source Alternative for Enterprise Content Management (ECM). Alfresco is the leading open source alternative for enterprise content management. It combines the cost effectiveness of open source software, with the stability of a true enterprise-class platform.

drupel

Drupal is a powerful alternative to Joomla or Mambo:
Drupal is a content management system that allows an individual or a community of users to easily publish, manage and organise a great variety of content on a website. Drupal is open source software licensed under the GPL, and is maintained and developed by a community of thousands of users and developers. Read more at Drupal

expressionengine

ExpressionEngine is a flexible, feature-rich content management system that empowers thousands of individuals, organizations, and companies around the world to easily manage their websites.

moveabletype

Movable Type is a flexible,  blog software can be configured in as many different ways as there are ideas. More publishers and media companies choose Movable Type than any other blog software.

Flexible, powerful and fully customizable, Movable Type enables you to quickly create and publish interactive websites and blogs that foster passionate, loyal audiences.

PHPnuke

PHP-Nuke is a web based news publishing system specially designed to be used within Intranets and on the Internet.

The Administrator has total control of the web site via a web based interface, effectively having a powerful assembly of tools at their fingertips facilitating the maintenance and operation of an actively managed web site.

Read more at PHPnuke

PHPBB

Since its creation in 2000, phpBB™ has become the most widely used Open Source forum solution. Like its predecessors, phpBB™ 3.0 “Olympus” has an easy to use administration panel and a user friendly installation process, which allows you to have a forum set up in minutes.