ToeTag is a map level editor for Quake 1, written from the ground up for Mac OS X with Objective-C and the Cocoa framework. All you need is a working Quake installation and you're ready to begin making maps - ToeTag provides everything else.
oliveratgithub/ToeTag
The only Quake 1 Level Editor built natively for Mac OS X. See more:
Objective-C