A port of id Software's Quake to the Nintendo Wii and GameCube.
Be sure to check out the user guide if you are new to Quake or Wii/GameCube homebrew.
Extract the downloaded file into the Apps folder in the root of your SD card.
If you don't own the full version, the shareware version with PAK0.PAK is also available for download here (Quake_shareware.zip). If you own the full version, the PAK files are inside Quake's ID1 folder on your computer.
Copy the PAK0.PAK (and PAK1.PAK if you own the full version) file to "/apps/quake/ID1" on your SD card.
You're now ready to open the game on The Homebrew Channel menu.
You can optionally install the Channel forwarder for your Wii System Menu (QuakeGXWii_Channel_Forwarder.wad, MD5: DC2BA822A20D9E813D0F37C2AD77F66F) with your preferred WAD manager. It points to "/apps/quake" on your SD card.
Based on the original GameCube port by Peter Mackay. The continuation of the project was Quake GX, by Eluan Costa Miranda. Along with Wii64, this was the first homebrew that implemented full hardware 3D acceleration on the Wii. You can read more about it here:
https://twitter.com/eluancm/status/1428786509986029568
https://eluancm.net/projects/quake-for-the-nintendo-wii/
https://www.youtube.com/watch?v=xTSa5NsHxJI
The second fork was Quake Wii, by Piko.
The third fork was Quake Rev PAK, by Izhido.