I forget exact HOW I came across this, but in any event, if you want to take a trip back down memory lane to the year 2003 I recommend you head on over to: http://www.halodemomods.com ...and download the HaloMD app. I thought I would have to follow a series of complicated steps to get it running..but no! Download, run the installer and bam. That's it. You might have to tweak the video settings but it plays real well and you get to play one level from the single player game - or join a multiplayer match at Blood Gulch! I think you're limited to just other HaloMD players (of which I doubt there are many) so don't expect a full 16 player game. But I'm in heaven. Can't believe I'm playing Halo on my Mac...craziness.