SF.net page (Read realese notes carefully!)
So far it can work with meshes (OBJ), lights, zones (OBJ), placetags, ball-socket and hinge joints.
You can test map in OSRPG Maggun.
Usage under Windows
Read about OSRPG Maggun first.
Then unpack editor-0.5.1_exe_src.tar.bz2 to C:/Trash
Modify C:/Trash/editor-0.5.1/settings
so that
DATA_DIR=C:/Trash/data/
screenshot