Before MMOs like Everquest and World of Warcraft, there were MUDs.  MUD stands for Multi User Dungeons.  Unlike MMOs, MUDs are completely text-based.  This means a coder writes a description and you get to use your imagination to paint a picture in your mind.  Before MMOs, MUDs would have hundreds of players online at a time and sometimes there would even be a waiting list to get in (not so much these days, but usually there is 100+ players on during the day).

I enjoy the MUDs that I write for, not so much for the game, but more for the community.  I have found in MMOs that even though there is a great range of ages, most of them have a high level of immaturity.  For the most part, MUDs usually have a couple of annoying people and they get ignored. 

I enjoy writing for MUDs because it is a creative outlet for me, though a lot of the time I'll have writer's block which I can overcome if I just start typing.