I've composed a preliminary installer for RenderMonkey stuff that was developed this summer (python plugin rewritement + some kind of previewer). You are expected to run windows and RenderMonkey 1.6 is expected to be installed somewhere before launching installer. Root credentials for user that runs installer is also expected.
There is no mention of license in the installer right now, but it is MIT.
URL:
http://sukhoy.public.iastate.edu/soc200 ... ller20.exe
Note that the whole plugin logic is now implemented in python. Besides, it means that you do not need visual studio to tweak things - just text editor.
The missing part is of course docs on rmsdk wrapper and on minimal ogre wrapper I had to write - oh yes, with boost::python (it is no trouble, although PyOGRE folks for some reason think so

). There was some reason why PyOgre was not an option - primarily because of material serializer lack, but after that I had to develop "fake material framework" just to use that serializer properly, so probably doing mini wrapper was the best thing I could do for now. The previewer itself is extremely simplistic, just slightly redesigned example framework which maps given material over ogrehead. I used to have had some code which deals with RenderMonkey geometry, but because of flaw in my backup strategy it is gone - I plan to resurrect it once stop mourning

.
As for functionality - the functionality is pretty much the same except that now builtin OGRE serializer is used (through "fake" material framework), so the result is expected to be much more robust against possible changes in material framework. I think I will add zip file support and GL branch pretty soon.
And I expect this version to be much more tweaking-friendly, as I mentioned above.