Until we get a nice locally-hosted embedded MUSH client here in the browser for you, check out our listing at Mudconnector. They've got an embedded window that will do you just fine for a first visit.
For long-term MUSH gaming, you're probably best off with an app. A non-exhaustive list (let me know if your favorites aren't included here):
- MUSHClient (Windows)
- SimpleMU* (Windows)
- Pueblo (Windows)
- Potato (Windows, Mac)
- Savitar (Mac)
- TinyFugue (UNIX, Mac, Windows)
- Mudlet (basically everything)
- BlowTorch MUD Client (Android)
Once you've got one of those, the login address is telnet://www.darkmetal2039.com:2039.