i just played on a "Zombie" mod server last night! holy crap that was insane

25 guys running around with almost unlimited ammo fighting off a hoard of 25 zombies that infect you by knifing.
they look like the monsters from doom.
Terrorists/Zombie objective = infect all players
CT/Human objective: kill all zombies and or stay alive by hiding
oh yeah and the zombies have 500 hp and can heal.
once you get infected you become one and turn on your team mates
oh how i laughed hearing the panic filled screams over the mic
"Help! HELP!"