I've written a number of programs over the years that display and rotate 4D objects. My latest is the first to use OpenGL to render something other than wireframes. It's still kind of raw, but at least it can show the six regular 4D polytopes. I'm rather proud of the rotation interface.
If you have a Macintosh running system 10.5 (aka Leopard) or later, you can try it out.
http://www.megaseattle.com/james/Polytopia/
If you don't have the right hardware, you can at least look at some pictures.
http://www.megaseattle.com/james/Polyto ... ml#gallery
Any and all constructive suggestions are most welcome. And if any OpenGL gurus can tell me why turning on "multisampling" isn't giving me the anti-aliased edges I expect, don't be shy.
Thanks, and Enjoy!
James