Now this (openproj) looks like a serious MS Project killer ! (thanks to Alberto Passalacqua for the link) It's opensource and free of charge, written in Java and hence runs on many platforms (including Linux, MacOSX and Windows). Licensed under the OSI-approved CPAL 1.0 (Common Public Attribution License) which looks OK (grants right to redistribute and modify, as well as forces availability of source code) and sources are said to be available really soon. Gave it a quick shot and it really seems to be sporting all of Project's features (computes effort to duration, etc...) -- it even looks a lot like Project's UI, I just hope it doesn't have all the bugs.. I guess not ;) w00t!