It's been around for a while but only recently has it become a decent editor.
It's a level editor for MZM and MF, this could be fun!

http://interdpth.blogspot.com/ :o

Note: You will need the US/EUR version of the roms or they won't work.
Don't ask me for them.

Very, very interesting. I'll have to check this out soon. The biggest question in my mind right now is, how do you get to edited areas? Just play the game until you're there?

Yeah, I tried to use this before....maybe this time it'll work. >_>