A group called Falling Leaf Systems have announced a preview build of what they call "DirectX 10 compatibility libraries":

As a fitting start to this blog, I'm proud to release a preview of our DirectX 10 compatibility libraries. These libraries allow the use of DirectX 10 games on platforms other than Microsoft Vista, and increase hardware compatibility even on Vista, by compiling Geometry Shaders down to native machine code for execution where hardware isn't capable of running it. No longer will you have to upgrade your OS and video card(s) to play the latest games.

Brave souls can install it and test samples from the DirectX 10 SDK, but it seems noone has posted success tales in that particular blog at least.

Pretty interesting if it turns out to be a workable solution; certainly further reduces the need to consider upgrading to Vista for gamers.

Awesome! I plan to avoid Vista as long as possible but once Crysis comes out I may make the switch or some kind of dual boot setup.

These compatibility libraries won't really do much for games that look for specific code in a specific dll that isn't part of direct x though :(

Sounds like it'd be slow

Sounds like a waste of time. If you need DX10, just buy the damm OS and dual boot.
You'll all be using it eventually

Sounds like a waste of time. If you need DX10, just buy the damm OS and dual boot.
You'll all be using it eventually

Spoken like a true slave

I would switch to mac if my games worked on it.
We are all slaves

Sounds like it'd be slow

Yer that was my first though. Like all those Glide wrappers back in the day.

Sounds like it'd be slow

If it's just shader compiling, it seems like it'll just mean that there's a "Compiling Shaders" screen on first boot where you wait for a minute for everything to bake if the title's tailored for it. Either that, or it does it on the fly and you have some minor hitching for the first few mintues of your first session.

Either way, it doesn't sound like it'd be a constant framerate hit based on what they've revealed so far.

A few people have since posted to the comments that indicate that it's not all as complete as one might hope:

I wonder, did you guys actually RUN the software? It runs Tutorial12, yeah. In FFP. With glBegin/glEnd. Without GUI/reflection. Perhaps it even runs other tutorials - it does not run the demos, it does not run my simple app just because there's no D3D10CompileShader implemented.

Oh, btw, have fun writing your own shader/effect compiler. And reverse engineering D3D10 HW shader format (and also compiled effect one) to make actual games (not SDK samples) work.

You will never complete this.

^^ sounds like that was posted by a cranky employee trying to discourage them. :)

This could actual work quite well... If you have DX10 hardware (NVidia 8800 etc..) I can't see why this would run any slower if the shaders compile to correct code...

A full screen game running in Vista using standard Win32 DLL's only (no new features outside of DX10 that is) and a hacked DX10 DLL library is viable...

So without looking at how they attempted to do this, if they have taken the DX10 DLL binary files, hacked em so they execute under XP (take out the "Can only run on Vista and better" code) then the resulting game should be 100% the same...

Then again, if they have tried to implement there own shader compiler, then I wish em luck :)

I still don't get how you can compile geometry shaders down into something that runs on a card that doesn't support geometry shaders.

But isn't it meant to be for a DX10 card running in an XP machine?

by compiling Geometry Shaders down to native machine code for execution where hardware isn't capable of running it. No longer will you have to upgrade your OS and video card(s) to play the latest games

Makes it sound to me like they're attempting to make DX10 functionality work on older video cards.

Ah, yes. It does look a bit like that hey. Apology accepted then.