What about on linux?
What you are looking for is wxFred. It is basically just a gui that looks vaguely like FRED2Open and doesn't do anything. If you are interested in helping port FRED2Open to wxFred it (or you know someone that is) the most recent version can be found in the SCP source code repository and if there are any questions they can be asked on IRC in #SCP or on the SCP board.
wxFred did compile the last time I checked but that is getting to be quite a few months ago.