User blog comment:Drkdragonz66/Call of Duty: Iron Wolf?/@comment-1873625-20120102205510/@comment-1191892-20120102212523

IW engine is an updated Id Tech 3 (ie Quake 3) engine. Which is what the original Call of Duty ran on.

Comparing it to other engines minus AAA games with their own modern engines means you're basically just comparing it to UT3 (an engine which is itself seven years old).