I have a PowerMac 8500 with an ATI Rage Orion card. After installing OS 9 (with OpenGL 1.1.1), I discovered that all my programs that utilize OpenGL (Quake 2/3 and my own personal programs) did not work. They would load, but the graphics were random lines. Apparently, in order to use OpenGL in OS 9, you need the updated ATI drivers that come with OS 9. If you have a G3/iMac/etc., the installer will update you extensions automatically. However, if you have a ATI-brand board, the installer will not. In order to get OpenGL to work, I had to use TomeViewer and extract the ATI extensions manually. After that, everything worked great (a little faster, I might add).