It seems the author of RGM is working on a new version. RGM 5.xx will now support 128x128 resolution for textures and sprites and 640x400 resolution for screen bitmaps. This makes previous versions of RGM incompatible. No release date or any other info has been provided yet. This is very exciting news for the RGM community, as this will spark even more interest in RGM.
Info was provided from Bithandler.com. The old RGM website does not seem to be up at this time. I would presume that this is the new site for RGM.