I have a console based (
But there is a standard console for Java applets :)
Joking aside, there does seem to be some console code on this site: http://math.hws.edu/eck/cs124/javanotes2/source/index.html. Apparently you can just extend this class and it'll give you a console in your applet. However, you may need to redirect System.out (standard output), System.err (error output) and System.in (input) into the console. That doesn't seem to be implemented but could be blocked in applets by the SecurityManager.