You misunderstand *why* OpenGL exists in the first place. It's an open API. DirectX is 100% proprietary, and is only supported under Windows. Supposedly an upcoming version of Virtual PC will allow Mac gamers to play DirectX-only games, and there's already Wine and WineX for playing non-ported games under Linux. Still, that's not good enough for some people.Open GL is a dying breed. It will be replaced with DirectX9 games soon, such as Halo.
but Nvidia's video cards supports OpenGL! ! ! doesnt that matter ??
OpenGL won't be dying anytime soon, not as long as companies like id and Epic continue to support it.
I'm royally pissed about Half Life though. With the original, most of the game servers running were Linux servers. Was there a Linux client? Nope. Could it have run under Linux? Yes, even the Windows version supported OpenGL. Linux gamers who were hopeful for a Linux client got screwed, and Valve has already shown that they have absolutely no intentions to release anything more than a Linux server for Half Life 2.
As for Halo... it *would* have been an awesome OpenGL game, if Microsoft hadn't bought Bungie, and left their Macintosh loyalists out in the cold. Also, no co-op in the PC version; what's up with that? If Bungie had remained thier own company, there may have even eventually been a Linux client. But noooo... MS just HAD to have that killer app for the XBOX.