Tracks is a web-based application to help you implement David Allen’s Getting Things Done™ methodology. It was built using Ruby on Rails, and comes with a built-in webserver (WEBrick), so that you can run it on your own computer if you like. It can be run on any platform on which Ruby can be installed, including Mac OS X, Windows XP and Linux. Tracks is Open Source, free and licensed under the GNU GPL.
Streber is a free wiki driven project management tool written in php5. Freelancers and small teams can easily setup projects and keep track of tasks, issues, bugs, efforts etc. Project-User-Rights can be adjusted e.g. to provide clients a limited view of the current project state.
It supports very easy Installation with FTP.