A.C.E. Mod is a full conversion modification for Bohemia Interactive's ArmA 2 Operation Arrowhead.
Its a great mod.
Nothing else like it.
In terms of quality, this is one of the best mods I have ever seen. Especially the optional sound mod. People who like immersive games and realistic first person shooters will love this mod! If you thought ArmA II was realistic, get ready to have your mind blown away. You will never want to go back to the vanilla AmrA II.