I just spammed a Portuguese site (I'm Portuguese) that was talking about the Win8 entering in production....there was a flame war there against Win8 and i simply copy and pasted the info about L4D2 extra speed under Linux
Honestly, instead of all this "we vs them" kind of thinking, I would love to see Microsoft open source more of their tech... maybe some day.
A more balanced perspective I guess.id Software mad scientist and first-person shooter "granddaddy" John Carmack said that DirectX has matured to the point where it's now a better API than OpenGL. It handles multi-threading better and newer versions manage state better. But he doesn't have plans in moving to DirectX any time soon, blaming inertia for the studio's continued use of OpenGL.