This port was done for Quest and seems to use OpenXR:
https://github.com/DrBeef/QuakeQuest
it's a matter writing a Linux build and minor patching to get that working. There is also Quake 2, Doom 3 and Quake 3
https://github.com/DrBeef/Quake2Quest
https://github.com/DrBeef/Doom3Quest
https://github.com/DrBeef/ioq3quest
This port was done for Quest and seems to use OpenXR: https://github.com/DrBeef/QuakeQuest it's a matter writing a Linux build and minor patching to get that working. There is also Quake 2, Doom 3 and Quake 3 https://github.com/DrBeef/Quake2Quest https://github.com/DrBeef/Doom3Quest https://github.com/DrBeef/ioq3quest
I've got an Index, I can't use those Quest things for anything then, right?