The mod has taken the shooter world by storm with its blend of realism, unforgiving gameplay, and brain-munching undead. The project turns Bohemia Interactive's Arma 2 into a desperate fight for survival in a world ravaged by zombie apocalypse. While the mod isn't technically an MMO, its persistence and massive world are certainly MMO-like.
DayZ is on track to overtake the sales of the game on which it is based. "Currently we're running 22,000 concurrent at full peak, and 10,000 off peak, which is pretty huge numbers considering the original data structure and system was designed to handle 100 concurrents and two servers," he said.