Not only has Valve Software successfully ported the first-person shooter game Left 4 Dead 2 to Linux, but it actually runs faster on the open source OS than on Windows.

Using high-end hardware, a version of the game running on Ubuntu 12.04 renders at 315fps, Valve's Linux team reports. That's a 16 per cent improvement over the Windows version, which only clocks at 270.6fps on the same configuration.

There was no magic involved. When the Valve developers first ported the game's code base over to Linux, the game crawled along at just 6fps. Only after the code was optimized to take advantage of the Linux kernel and video drivers did it manage playable speeds.

Throughout the porting process, Valve also worked with video card makers to squash bugs and remove bottlenecks, which should help to improve performance of all games running on Linux.

But what the Valve developers didn't expect, they say, was how much of the performance gain was attributable to OpenGL, the cross-platform graphics API that they used to implement the game on Linux.

Normally, the Windows version of Left 4 Dead 2 uses Direct3D, Microsoft's own, proprietary 3D graphics API. But when Valve developers built a new Windows version of the game based on OpenGL code borrowed from the Linux version, that version also ran faster than the Direct3D version, at 305fps.

Valve says its developers are still investigating why the OpenGL version performs better on Windows, and that it will use what it learns to improve performance on the Direct3D version.

The results are bad news for Microsoft, however, which has already taken its share of knocks from Valve co-founder Gabe Newell.

The Linux port of Left 4 Dead 2 is just part of a larger plan to bring Valve's entire Steam gaming platform to the open source OS as a "hedging strategy" against Windows 8, which Newell believes could be "a catastrophe for everyone in the PC space."

In the long run, Newell says, he'd like to get all 2,500 games now available through Steam running on Linux. That's a tall order, but it may just be possible if it turns out that Microsoft's proprietary technologies make for an inferior gaming platform. ®