The way that I have always mapped muds is the old box and line method. A square/rectangle/triangle/circle represents the room and the line represents the exit to the next room. While I don't know of any program that does that specifically any raster or vector program can draw boxes and lines over a grid. Myself, I always used graph paper and pencil, scanned it in, then went over it in Paint Shop Pro, and uploaded it. Fancier maps forced me into Photoshop but that would be overkill for box and line. If you haven't ever looked at the DragonRealms maps then I would suggest looking at those...Sallion and myself did the early mapping for that game but that world has changed a lot in the past 15 years and others have taken over since we retired in 1998. But I digress. Different people can upload their map and then all you need to do is create a table and put each map into that table and then they will all align properly. I'm sure that there are far fancier tools nowadays than tables so those familiar with web stuff can handle putting it all together.