For quite some time I've been searching for a web-based, open-source project management program that I can run on my rented space at Dreamhost to track client projects. dotProject seems nice, but I've never figured out how to create projects that only certain people can access. I'm usually working on two or three projects at a time for different clients, and would like to be able to allow access for each client to their project but not others.

So, first of all, can anyone point me to how to do this in dotProject, and baring that, can anyone recommend an open-source solution to this problem?