From TDN

TGE, being a full featured Game Engine can often be a burden to manage when coupled with a large development team. There are many solutions available to help this situation, on both the web and desktop fronts. This page was written to make users and producers aware of popular solutions which are in the indie cost range.

DotProject is an open-source project management system written in PHP. It offers time tracking, forums, trouble ticket management, and file sharing.

Overlord is a cost effective PHP based project management system that was written primarily for game project management. Features include file storage, fine grained per-project permissions, and bug tracking. It is featured on GarageGames' web store and is used by many of the commercial TGE based projects.

SubEthaEdit is a collaborative editor for Mac OS X written in Cocoa which offers shared workspace project management and extensive code syntax highlighting functionality for multiple languages.

Gobby is an open-source GTK-based collaborative editor for Windows and Linux which is a chat room with code workspace sharing, syntax highlighting, and encryption features.

Trac is a web revision control system that integrates with Subversion. It offers project management, bug reporting, and a wiki which are presented in an integrated web interface.

activeCollab is an easy to use, web based, open source collaboration and project management tool. 100% open source, 100% free. No limit on amount of users and projects. ActiveCollab is no longer free.