ZombieMod takes a unique approach on the Zombie Apocalypse by putting it in the perspective of a military commander, not a survivor. Since it is 2 years after the first infections, resistance on the east coast is organized, resulting in battles rather than small groups fighting for survival.
These two pictures show a sample of the Zombie teching system. Much like the vCoH Wehrmacht tech system, the Zombies advance in stages of infection. With each tier comes larger zombie squads, some new squads, and other abilities.