Turtle Rock has collaborated extensively with Valve in the past, having previously worked on the Xbox port of Counter-Strike, as well as Counter-Strike: Condition Zero and various maps for Counter-Strike: Source. That long history between the companies made acquiring the studio an "easy decision," according to Valve President Gabe Newell.
"We have been seeing very strong growth with Steam and Source, our content distribution and development platforms, up over 150 percent over the last 12 months," he said. "Given our expectations for Left 4 Dead and our long-standing relationships with members of the Turtle Rock team, this was an easy decision. It also gives us a base from which to expand our development activities in the Los Angeles area."
Michael Booth, CEO of Turtle Rock who founded the studio in 2002, said, "Valve has had great success in bringing in projects and teams such as Team Fortress and Portal. As I spent time working and talking with the creators of those products over the past several years, it became clear that this was the right next step for myself, my colleagues at Turtle Rock, our customers and our products. We are excited to be a part of such a visionary and forward-thinking company."
Left 4 Dead pits four survivors of a medical holocaust against the Infected, humans who have been afflicted with a mutating disease. In-game AI will allow for fewer than four players at a time, with excess survivors handled by bots. Human players can also take control of up to four of the Infected. Left 4 Dead is currently scheduled for an early 2008 release, for the PC and Xbox 360.