I recently added a Quake enhancement package that includes the no-charge shareware version. You can copy your retail game data to play the full version with the same enhancements. This package *does not* try to keep the original look/feel/gameplay; instead it completely modernizes Quake and takes full advantage of everything the Darkplaces engine can do, and the result is pretty impressive.
-High def, normal mapped, gloss mapped, glow mapped, and luma mapped textures
-High def, normal mapped model skins with shaders
-Weather effects like rain, snow, fog, mist
-High poly weapon models with high def, normal mapped, bump mapped, gloss mapped, skins
-Particle effects for fire, blood, magic, special effects, etc.
-Transparency shaders for water, slime and special effects
-High def moving skies
-Real time world illumination, real time shadows, and colored light sourcing
-High quality sound effects and new music soundtrack
-Gameplay enhancements: new HUD, press f for flash light, mouse2 for melee attack, start enemies on fire or gib them for health boosts, enemies can poison you or ignite you (read /usr/share/doc/Readme-PPCUtopia-Quake for full explanation)
-Several new enemies
Before installing this, update RetroBlazer if you have it installed to avoid config conflicts. I configured this package to give acceptable fps on my X5000, running a Radeon HD6870. If you experience poor performance disable the real time world illumination "RT World" in the Options>Lighting menu.
apt-get install quake-enhance-pkg
---Casey