Valve has made Dota 2's Direct3D to OpenGL translation layer open source. This is the piece of code that allows Valve to take a standard DirectX Windows game that uses the Source engine (Dota 2 ...

Fingers-crossed this means we'll start to see more older Source Engine titles getting OpenGL updates for SteamOS increasing its native library. Maybe, one day, we'll even see Titanfall.

How difficult is OpenGL? How difficult can it be if you can build a basic renderer in 500 lines of code? That’s what [Dmitry] did as part of a series of tiny applications. The renderer is par… ...

Valve releases open source Direct3D to OpenGL translator It should aid porting Windows games to other platforms, but it won't be revolutionary.