Valve Corporation, publishers and developers of the critically acclaimed Counter-Strike, Half-Life and Team Fortress franchises, have today announced the first piece of DLC (downloadable content) for the zombie thriller Left 4 Dead on PC and Xbox 360, entitled the L4D Survival Pack, which introduces the new Survival multiplayer mode and two new Versus campaigns.

A Critic’s Choice edition of Left 4 Dead will be available in retail stores and on Valve’s leading digital distribution service Steam in Spring, which includes the game and full access to the Survival Pack content.

Also announced today was the Left 4 Dead release of the Source SDK, allowing budding developers and modders to create their own campaigns for Left 4 Dead. The Source SDK will also be released in Spring for PC owners of Left 4 Dead at no additional charge.

“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.”

— Connor Beaton