There are plenty of java telnet emulators out there, but in my experience they do not do a good job of seperating the telnet session handler from the terminal handler. I've used this to incorporate a quick telnet to another host into my programs. Sometimes you just want to go to another machine and start a server, but you also want it to work on many different platforms; making that easy is the intended purpose of this package.
A good place to start if you have problems is with these two RFC's.
For bugs reports or and flames send it to danielk@zenyu.com