Well, almost. I have found a workaround that enables Glide-equivalent performance under Windows XP using OpenGL, including RC1 and above. At the moment, I will supply specific instructions, but I soon will provide drivers on my site. The secret to this is a beautiful little product from Metabyte, known as WickedGL. These replacment OpenGL drivers enable performance either equal to, or in the case of any Quake 3-engine games (and many others), performance WELL ABOVE the standard level of Glide and OpenGL. All you 3dfx owners out there who cannot play Tribes 2 due to consistently low framerates, breathe easy - these drivers can double the performance of the game. In the case of Unreal Tournament, if yopu have ever used OpenGL support as your 3D renderer, the 1/2 frame per second performance would be enough to scare anybody off. However, with the addition of WickedGL, the performance is equal to that of Glide. So in theory, Glide still doesn't work, but there are very few games out there that supports Glide and not OpenGL. Anyway, I'll stop harping on, and give you 3dfx-owners the lowdown on how to get this working.
 
1. Many 3dfx owners would have noticed that not only has Glide ceased to work, but also OpenGL. A quick-fix for this is to take the two 3dfx driver files from any pre-2485 Whistler or XP CD, located in the /i386/drivers.cab file. I cannot remember the names of these files off the top of my head, but they are fairly obvious, both containing '3dfx' in the filename. Don't bother with the .ini file, we dont need it. Now, in order to enable Open-GL, we must use these files in place of the drivers of your choice (My reccomendation is the Omega 1.02 Voodoo 3/4/5 drivers, available from Voodoo e|Extreme.) You MUST install these drivers first, then simply replace the two files in the /windows/systeh32 directory with the two files taken from the drivers.cab file. And voila, OpenGL support! Test this with any OpenGL game (at the present time, I have not been able to get Half-Life Blue Shift to work, however it does not appear to work under Windows ME either. If any of you have had any sucess with this game in other than D3D, let me know). If you haven't tried using OpenGL in Unreal Tournament, try it now - you'll be amazed at the difference WickedGL will make.
 
2. Now that we have OpenGL support (albeit a poor 3dfx-implementation of it), we can install WickedGL. The demo version, 3.01 at the time of writing, is available at http://www.wicked3d.com/technology/wickedgl.htm. These demo drivers are fully functional, however give a brief demo message at the 3dfx spash screen, and place a temporary watermark at the top right hand corner of the screen, however this dissapears after a minute or two. Once you have downloaded and installed WickedGL, be sure to read the readme file, wich has many specific instructions to get maximum performance for each specific game. (NOTE: If Tribes 2 gives a very prettey coloured but annoying screen during gameplay, be sure to set textures to 16 bit, not paletised as the readme says.) Once you have done all this, test all your games - I garuntee you will not be dissapointed. Who needs Glide, when you can get better performance, and Windows XP support from WickedGL?
 
Anyway, good luck to all you 3dfx-fans (and haters alike) - I'll let you all know when I have posted the proper drivers on my site, and I'll post any further instructions on how to get many games working if any of you have any difficulties.