Some may have already tried Windows 8 but the rest of the world is still waiting for its official commercial release.  Microsoft keeps bragging about its Metro user interface and how awesome it would be great with apps and touch-based devices.  But there’s one group that Microsoft seems to be forgetting–PC game developers.

While speaking at the Casual Connect game conference, Valve CEO Gabe Newell described the new Microsoft OS as “a catastrophe” for PC game makers.

Don’t get his words twisted before you understand what he’s saying.  Not that Windows 8 is not a great platform for PC gaming but the problem is the closed nature of the Windows 8 store.  PC game developers had always counted on the openness of the PC platform, and Newell knows this only too well since the success of Valve has been due to this.

Newell compared the Windows 8 store to Apple’s walled garden wherein developers turned their backs on the platform because closed platforms limit their capabilities.

“We’ll lose some of the top-tier PC/OEMs, who will exit the market. I think margins will be destroyed for a bunch of people,” Newell stated.

So they’re extending their business to Linux in preparation for the Windows 8 arrival.  They recently announced that Steam, their digital-distribution platform for video games, would be available for Linux as well as their Source Engine which is their 3D game engine that runs Valve’s popular games such as Team Fortress 2 and Half-Life 2.

“We want to make it as easy as possible for the 2,500 games on Steam to run on Linux as well,” he said.

Newell’s statement doesn’t necessarily mean that they’re abandoning the Windows platform, they’re just testing the waters and creating a fallback in case things start to fall apart.