Actually, Lightning, the Steam version does not use DRM. It's simply a matter of definitions. Some people define Steam itself as the DRM, others see it as the distribution system, and the optional copy protection components as the DRM. Personally, I fall into the latter category, but I understand the argument of those who fall into the former. Steam was used on the discs simply as a means to update the game, as once it's installed it does not require Steam to operate.