Hosting and domain costs until October 2024 have been generously sponsored by dumptruck_ds. Thank you!
Worldcraft
From Quake Wiki
Worldcraft
A graphical level editor for id Software's Quake, Quake2, and Hexen2 Worldcraft lets you make your own game maps quickly and easily. Worldcraft uses a technique called constructive solid geometry (CSG) to create maps. It was one of the only few Quake map editor for quite a while back in the day and has since developed into a Half-life/Half-life 2 only map editor.
Worldcraft's Quake related pages can be found archived here:
[1]web archive