Valve has just announced several content and development releases for Left4Dead.  The first DLC (Downloadable Content) is dubbed the Survival Pack and will be released later this spring.  It will introduce a new multiplayer mode, Survival, and two additional Versus campaigns.  In addition, a retail version including the Survial Pack will be released entitled Critic's Choice Edition. 

In addition, PC gamers will soon be able to enjoy the Source Software Development Kit (Source SDK) which will allow the creation of custom Left 4 Dead campaigns that will be discoverable via the game's matchmaking system. The SDK update is also due for release this spring, and will be free of charge to all owners of L4D on the PC.

"Since Half-Life launched in 1998, Valve has made continuous efforts to expand the offering of its products beyond what's included on the day of launch," said Gabe Newell, co-founder and president of Valve. "With Half-Life and Counter-Strike, and more recently Team Fortress 2, we've learned that we're no longer making stand-alone games but creating entertainment services. With Left 4 Dead we're extending that tradition by creating additional gameplay and releasing our internal tools to aspiring developers so they may also create and distribute new Left 4 Dead experiences."

Left 4 Dead is a survival action game from Valve that blends the social entertainment experience of multiplayer games such as Counter-Strike and Team Fortress with the dramatic, narrative experience made popular in single player action game classics such as the Half-Life series of games. Released in November of 2008, L4D has earned over 25 industry awards from outlets around the world.

For more information, please visit the official website at www.l4d.com