[www.evennia.com]

As it is basically a framework to build a modern mud in python, but I don't know that translating CF would work all that well. You'd probably be better off starting from scratch and building something new that has some of the focus of CF (PK, RP, etc.)

Also it has a built in web client thingy, which makes it way more accessible to new people than telnet/client/flashmud garbarge.