>>Is Rampant another AI I don't know about?
>
>Rampant is the state of semi-insanity that happens when an AI
>partially crashes its system. Durandal, at least in the Marathon
>games, is a Rampant AI (hence the signature line "Yours in Rampancy").
>
>Feel free to correct me if I'm wrong, anyone. It's been many years
>since I played Marathon, so my memories more than a little fuzzy.
>-Eliot "Marathon - like Doom, but less suckage" Lefebvre

If I remember correctly, Rampancy had four stages (well, officially 3, but with the whole 'escaping the heat-death of the universe' thing, most people theorized durandel had moved into a fourth stage of rampancy).

For the ultra-curious, there are several links about Durandel (from Marathon) with the occsional tidbit about his original rampancy, from the game:
http://marathon.bungie.org/story/durendal1.html
http://marathon.bungie.org/story/durendal2.html