Here is ZeroRadiant win32 build.
How to get it working:
1. Extract using 7-zip, cause the compression method was bzip2.
2. I included two gamepacks (Nexuiz and Quake3). You can add more from svn following example.
3. When you extract the build, open games folder and edit required game file (eg nexuiz.game). You need to set correct enginepath_win32 location.
4. Now you can start radiant.exe. Two preferences files will be created (global.pref and local.pref). First time you'll start radiant for a specific game, you'll be asked for a default project file for that game. You can find these in game directories/scripts subfolder (eg nexuiz.game/data/scripts/default_project.proj). User project file will be created (location and settings can be found in local.pref file).
5. If you get any error, please read radiant.log file.
Anoyances:
1. Anoying red map window after starting ZeroRadiant second and other times. Probably colour can be changed somewhere in menus or global.pref. Didn't have time to search.
2. Very inconvenient texture packs list menu (especially when you have moved all your maps from dlcache to data).
Might be buggy. Please post if it does work (in)correctly.
If somebody needs compilation tutorial, I can post it when I'll be back after several days.