The first thing that modern man achieved after customizable game engines, of course, was figuring out how to make playing one game look more like playing another game, an activity which is as inscrutable as its appeal is universal.

Bungie games are no exception to this rule, and in the past there was not one, but two groups trying to make one Bungie game (Myth) look like another Bungie game (Marathon) was well as various ambitions for putting a Spartan from Halo into the Marathon engine; and who knows, when the Halo Editing Kit finally gets released, maybe some enterprising people will find out how to make the Halo engine play a game that looks like Marathon and thus surpass Aleph One as one of the coolest uses for legacy intellectual property.

The latest version of this, of course, is a mod for Battlefield 1942 based on Halo called Homefront; there's a preview of it over at Battleground: Halo. Thanks Rams for the heads-up.