Mambo is a full-featured content management system

LifeType is an open-source blogging platform with support for multiple blogs and users in a single installation

The open source survey application

The Amazing Little Poll is a very simple php polling script

Web Messenger is an open-source live support application written in PHP and MySQL

MODx helps you take control of your online content.

LinPHA is an easy to use, multilingual, flexible photo/image archive/album/gallery

Moodle is a Course Management System

Nucleus CMS is a flexible and easy to install content management system, aka blog software.

Its the easy to use, multilingual, powerful, feature packed, free forum software