This could be useful, for instance, with a help system which uses the user's favorite Web browser to display the help information. Another possible use might be joint web browsing where the Controller application specifies where several connected web browsers all browse to.
Controller is, right now, only proof of concept.
It is also free for all use, but you gets what you pays for, there are no warranties whatsoever. The Controller class is used in the application. It binds to a well known port to which the applets will connect. There is currently no retry. If the Controller isn't waiting at the port, the applet will not keep trying to connect.