The applet demonstrates Client Server
interaction via a rendezvous message passing protocol. Each
client calls on the server to perform a service. Requests are
queued to an entry. The Server accepts requests from the
entry, services them and replies. When the server is servicing a
client's request, its rotating segment colour is the same as that
of the client. Run the clients first so that when the server
starts, there are two outstanding service requests.