DotNetNuke is an open-source Web Application Framework ideal for creating and deploying projects such as commercial websites, corporate intranets and extranets, online publishing portals, and custom vertical applications.

Requirements: ASP.NET 2.0, SQL Server 2000 or SQL Server 2005

Joomla! is one of the most powerful Open Source Content Management Systems on the planet. It is used all over the world for everything from simple websites to complex corporate applications.

Joomla! is easy to install, simple to manage, and reliable.

Requirements: PHP 4.x or PHP 5.x, MySQL 4 or MySQL 5

Community Server is the award winning platform for rapidly enabling both small and large online communities.

Requirements: ASP.NET 2.0, SQL Server 2000 or SQL Server 2005

WordPress is a state-of-the-art semantic personal publishing platform with a focus on aesthetics, web standards, and usability. What a mouthful. WordPress is both free and priceless at the same time.

Requirements: PHP 4.x or PHP 5.x, MySQL 4 or MySQL 5

Since its creation in 2000, phpBB™ has become the most widely used Open Source forum solution. With a large and highly customisable set of key features coupled with a standards compliant interface, phpBB™ will grow with, and compliment your website.

Requirements: PHP 4.x or PHP 5.x, MySQL 4 or MySQL 5

Kbiki combines Knowledge Base system with a power and flexibility of Wiki! Kbiki provides WYSIWYG content editing without any alternative formatting Wiki-style constructions

One of the most popular community-based portals with a big choice of modules and languages. It's a news automated system specially designed to be used in Intranets and Internet.

Requirements: PHP 4.x or PHP 5.x, MySQL 4 or MySQL 5

Sugar Open Source is the freely distributed open source edition of the SugarCRM software. It is a production-ready Customer Relationship Management system.

Requirements: PHP 4.x or PHP 5.x, MySQL 4 or MySQL 5