well, ive searched, and all i got was shit bad stuff. i would like a copy of atcs, and i have looked inside to pk3 and took it out and looked for it on gtkradiant, and didnt show up. a link will be the best result, its none of your buisness why, and when the thingy is done, ill... do stuff
The best thing to do is decompile it yourself, or contact the developer and ask him nicely. decompiling will allow you to learn more about the mechanics of mapping.
There have been several topics like this, one very recently. Your best bet is just to go ask mrjex himself somehow.