several people start working on a map? to get the efforts packed back together:
http://forums.urbanterror.net/topic/11087-how-to-multi-mapper-map-project-with-diffmerge-tool/page__hl__radiant%20modelling%20shminky__fromsearch__1
files: the .rar is the windoze .exe, the .zip is for other OS
possibly the files above are older versions!