Q3Rally is a car driving and car combat standalone game. It is based on Ioquake3. Since the latest release (available at 20/08/18) also MacOS X (10.5 and above) is supported. Also Windows and Linux (x86/x64). Try it out. It's damn fast, baby.
These are all the necessary tools for Mapping for Q3Rally. Three map editors the compiler and the frontend for the compiler. With this and the mod itselfs you will be able to make nice maps for Q3Rally.