Perhaps you could release the coding to DreamMaker IDE (not the compiler) so that users may change what they'd like to with the interface of DreamMaker. The DreamMaker IDE could just use dm.exe to compile. I dunno, I'd just like to fool around with the IDE. Y'know, extend functionality with the DreamMaker file explorer, allow DreamMaker to start the "Open Project" prompt in the folder we specify, all sorts of things.
This would be nice, but there is nothing stopping you from created your own. Now that BYOND's DMIs are in PNG format, you will can understand the format by looking up how PNGs work(OK, technically that is only for the new betas). With dm.exe being released, you can even make your IDE compile! Seems like the map format is pretty simple(haven't looked at it myself), so you should have all your bases covered.