erverA</a></code> i o: The server; note that i is the request queue
                                     and  o the reply queue.
</li><li> <code>Int</code>: The timeout in microseconds.
</li><li> <code>Type</code>: The <em>MIME</em> type of the reply.
</li><li> [<code>Header</code>]: Additional headers to be sent with the reply.
</li><li> <code>Message</code> i -&gt; IO o: Transforms the request into a reply -
                          this defines the service provided by this
                          appl