Page "Hexen II" Paragraph 9

Hexen II, by way of the Quake engine, uses OpenGL for 3D acceleration.

However, due to the prevalence of 3dfx hardware at the time of release, the Windows version of the game installs an OpenGL ICD ( opengl32. dll ) designed specifically for 3dfx's hardware.

This driver acts as a wrapper for the proprietary Glide API, and thus is only compatible with 3dfx hardware.

Custom OpenGL drivers were also released by PowerVR and Rendition for running Hexen II with their respective ( and also now defunct ) products.

Removal of the ICD allows the game to use the default OpenGL system library.