The Left 4 Dead Survival Pack is now available for the PC and Xbox 360, free of charge to all owners of the game. The full change list for the PC release is below. In addition, both the retail and Steam versions of the game (PC and 360) are now available for a special price. Check Steam and local retailers for pricing details. For more information about L4D, please visit www.l4d.com

Set in the immediate aftermath of the zombie apocalypse, L4D's survival co-op mode lets you blast a path through the infected in four unique “movies,” guiding your survivors across the rooftops of an abandoned metropolis, through rural ghost towns and pitch-black forests in your quest to escape a devastated Ground Zero crawling with infected enemies. Each "movie" is comprised of five large maps, and can be played by one to four human players, with an emphasis on team-based strategy and objectives.

Survival Mode
• New gameplay Mode
• 16 maps including Last Stand
• Leaderboards
• 7 new achievements

Versus Changes
• 2 new versus campaigns
• Fixed a case where versus team score would continue to be recalculated after the score panel was displayed
• Fixed an issue with recalculating the versus score health bonus for a player when they are rescued from being incapacitated
• Fixed being able to start a swing as an infected, then teleport to the survivors and have the claw swing hit a survivor
• Fixed a case where teleporting to the survivors would not reset the ability timer
• Fixed an exploit where you could load the chamber of a weapon with bullets by holding down the melee key
• Fixed a case where it was not possible to join a game while it was in a finale
• Fixed a rare case where listen servers would speed up the game over time
• Removed convars related to melee fatigue
• Fixed a case where infected players would get a respawn time on their initial spawn into a map

Server Changes
• Made ms_force_dedicated_server not require cheats
• Add a message when queuing a heartbeat
• Simplified setting of game mode
• Removed convars director_no_human_zombies and director_holdout_mode
• Added mp_gamemode [coop,versus,survival]

General
• Added lobby join and leave messages