alt Hacker NewsI am not sure I understand your question- MUDs have a text interface, somewhat similar to a command line. It wouldn't be a proper MUD if it had a graphical interface- there are plenty of games out there that do this like Baldurs Gate. The files part of your comment I don't understand either.
Simply untrue.
There have been hundreds of MUD clients and many of them were not purely text based at all. Many had images and map screens built in.