The http.server.dispatchers vocabulary implements two responders which route HTTP requests to one or more child responders.
HTTP dispatcher examples

Pathname dispatchers implement a directory hierarchy where each subdirectory is its own responder:

<dispatcher> ( -- dispatcher )

Virtual host dispatchers dispatch each virtual host to a different responder:

<vhost-dispatcher> ( -- dispatcher )

Adding responders to dispatchers:
add-responder ( dispatcher responder path -- dispatcher )

The default slot holds a responder which receives all unrecognized URLs. By default, it responds with 404 messages.