Heard of Valhalla Games.

Palladium was good, but there were certain aspects of their rules that gave me fits.

I used (and continue to use) RoleMaster more as a basic framework and have done tons of customization to it for a variety of game settings.

And I agree with the thought of adding more of a player component to any system that's used to model COIN. One of the more difficult aspects of these situations is the lack of one leader (there are often MANY leaders, springing up and disappearing with great frequency) and the appearance of many new groups. Hard to do in a computer model that focuses on leaders.