LARDLAD  Another good reason to not use Windows at work. This program imported the MS Project Plan file perfectly (.mpp). I would usually have to launch Windows just to read these files, then I'd have to use a Project Plan license. The view isn't as flexible as I would like, it is a bit slow (Java) but it works. Just for the fact that it does import mpp files it is perfect for me and if all you need is to view a MS PP file, I recommend this program.  
(Version 3.9.1)