Yeah it's probably qw only. It's pretty easy to get it running these days with the recent clients. You can just download a qw client (ezquake recommended [0]) and extract the executable to your quake folder.

Alternatively you can download nQuake [1], a full pack with most things included except for the non-shareware maps. You can then just place the pak1.pak file inside the id1 folder and make it complete.

Good luck ;)

[0] https://ezquake.com/

[1] https://nquake.com/