Glide3-libGL provides a version of Mesa compiled to render 3D graphics
through Glide3, thus allowing hardware accelerated OpenGL on 3Dfx's 3D only
Voodoo 1 & 2 cards. Even with Glide3-libGL installed OpenGL programs will
normally still use the regular (possibly unaccelerated) videocard.

To use Glide3-libGL to run an OpenGL application on your 3Dfx Voodoo 1 or 2
start your application with the Glide3-libGL wrapper:
Glide3-libGL <appname> [args]

For example if you want to run ppracer without any args use:
Glide3-libGL ppracer