Frag Zombies

Frag Zombies is a set of rules for combining Steve Jackson’s Frag game with Journeyman Press’ Zombies! board game. Of course, ownership of both sets is required, so I’m not sure how useful it will be.

Zombie Infection Simulation v2.3

Ok. This is neat. It’s a Java window that shows how fast one infected individual can destroy a population.
Zombie Infection Simulation v2.3

Living Dead Zombie Rules

Living Dead is a set of free roleplaying rules for the zombie apocalypse.

Unheroic Samurai

Unheroic Samurai is a set of free wargames rules for combat with classical Samurai versus undead horrors.

Zombie Skirmish Rules

Table Top Titans have released Twilight, a set of free miniature wargaming rules for skirmishes in a zombie plagued world.