Hi and welcome.
We are glad about every new hand we can get. If you are a C++ coder help on our mapeditor is highly welcome. It's C++ - the game itself is C.
As you have noticed already, current UFORadiant isn't compiling on windows. I'm merging currently a lot of stuff from another radiant version named darkradiant. (see
here).
Imo the worst thing in the open source world is always the editor for your game. I would like to provide an editor for contributors to create high quality game content. To reach this goal a lot of work on the radiant codebase is needed. If we want to get new mappers and so on we have to improve the tools and make them easier (and even more important - make them more stable).
Especially about radiant, we have a todo list dedicated to it in our wiki. feature request, bugs and improvements. if you have more questions please ask and we will try to answer them. keep in mind that currently everybody who is working on radiant is trying to get into the codebase
We would be very glad to welcome you on the list of coders.