MS Project is not part of Office, so few “ordinary” people have it. We’ve often needed project-management tools, and about a year ago I put together the basics of a GANTT-chart based PM tool. We shoved it on SF, and I and others contributed bits to it every now and then in a pretty haphazard fashion.
A year later, it’s actually quite good, enough so that I’ve dumped MS Project for most of my PM (nb: this free one has only got a tiny proportion of MSP’s features, but it’s free, java, much easier to use, and runs on low-spec PC’s, which solves a lot of probs I’ve had with MSP!).
I thought it might be of some use to people here; like UML tools, good free GANTT tools are pretty hard to come by but really useful. There are some really pretty Gnome ones (linux only IIRC?), and there’s at least one other for java that’s actively maintained, but we looked at the source and decided it was even more hacked-together than what we had already. We did chat to them about merging a while back, so that may actually happen at some point.