I've been looking at other MUDs over the past few weeks, seeing if I could find a better one anywhere, and I couldn't!
Moongate had wonderfully colored outdoor maps, fully developed towns and NPC's, and many many quests, including the fun "global quests". What I like the best, though, is MateriaMagica doesn't have the standard list of exits at the bottom of your screen, but a type of "compass rose" showing you all the directions you can move, all closed doors, and weather the next room will be dark or not. Out of the game world, there is a equipment lookup, an atlas of the world and towns, a "Registery" where you can post bio's and descrptions of your charachter, and message boards for any and all problems, questions, or rants! Moongate also has very helpful and patient Immortals - hats off to Vassago and the crew! By FAR the best MUD/MUSH or whatever I've seen. One you try it, you'll never go back!