The menus pinpoint script files that are fetched over the net. Here is an example script file, and a tar file with all scripts.
The script (usually) connects to a running program that is waiting for a browser to connect. I wrote a program called demo_server (it is in the nhc source tree in the directory src/tracer/runtime). The demo server spawns new programs to run when someone connects to it. In the demo setup I did I had about seven demo servers running on dogbert (at different ports). I made a tar file for you that contains the Makefile with which you can start the demo servers. In the tar file is also the source code for my demo programs.
I'm not sure if this whimsy description is enough for you to get the demos running at York, but just ask if you have any problems.