Bohemia Interactive' Arma 2: DayZ Mod is now available for download for free on Steam for those who own Arma 2 and the expansion Arma 2: Operation Arrowhead.

The mod, created by Dean "Rocket" Hall for Arma 2: Combined Operations (the name given to Arma 2 and Operation Arrowhead packaged together) is a persistent multiplayer mod where players can go solo or team up with friends for survival in a world ravaged by an infectious disease.

A recent update to the mod brought several new weapons, introduced new ways to get infected and made the "zombies" more adept at tracking down survivors.

The free mod available on Steam is not the standalone version of DayZ. In a recent Reddit AMA, Dean Hall said that the standalone version is expected to release before April.