We know that Bungie could not retain any rights to Halo pretty much, but what about the engine itself? It's not like some other engines that can be liscensed to use in games, it's exclusive to Halo. But is there a special case for Bungie? Or did they have to make an entirely new engine from scratch? I think the Halo engine would be fairly good. I'm not sure how it'd hold up to MMO esque features, but as for looks, gameplay, and efficiency it's great.