You can't host a telnet one as far as I know. You can host any web based pages as long as they got x10 adds, not about piraracy/hacking....etc and they don't use resources excessivly.
Mikek's got it. It would require me installing a codebase (like the one I linked) on my account. As MUDs are text-based, they typically use very little bandwidth.
If it is not allowed, then I certainly understand. Doesn't hurt to ask though...