At Siggraph a few days ago it was made known by Microsoft that OpenGL will be fully supported to run natively on Windows Vista in applications using the venerable API. This is in response to a cry last year from OpenGL developers when Microsoft told developers that OpenGL would be layered on top of DirectX in their next OS rather than supported to run natively (via its own ICD) as it is currently in XP. The choice last year was made because Microsoft didn't want OpenGL (which takes full control of the GPU) to disable the Direct3D Desktop Compositing Engine which powers the Aeroglass UI. Unfortunately, to combat this, their plan was to lock OpenGL development on Vista by running a permanent version of OpenGL as a function of DirectX.

It was feared that this would seriously harm native OpenGL application performance (such as Doom 3) and unnecessarily halt the development of the API for future hardware advances. The original plan to piggy back OpenGL on DirectX and stop its development on Vista PC's was seen as an entirely pointless move by anyone missing from Microsofts payroll, so despite the year of uncertainty, it's good to see that Microsoft have reversed their stance. This also means that Aeroglass will have the option of being run under OpenGL as well, and according to Khronos (the team responsible for OpenGL development), will run the 3D interface quicker than DirectX by Vista's release. The Vista installation CD will not include the ICD out of the box, however as it is on XP, this will be included in hardware specific driver files making it moot for the end user anyhow.

The original worries of poor performance were partly debunked in this set of game benchmarks run by AnandTech on Windows Vista Beta 2, showing that Doom 3 suffered an identical performance loss under Vista to all of the other Direct3D powered games tested. What's unknown however is whether by the time Vista ships and (it's assumed) Microsoft fixes the performance issues with Direct3D games, if OpenGL performance would still suffer the 20-30% performance drop seen in those charts. Hopefully with this weeks news both DirectX and OpenGL applications will run with equal performance to XP under Vista when it ships next year.

OpenGL a toujours été une couche à directx dans toutes les versions de Windows, dans vista Opengl sera natif mais pas développé par Microsoft, il est fort possible qu'il sera plus facile de porter les jeux windows sous linux.