the name of the system "unofficialy" is Eliza.
who ever did that one, did not take the time to make it very interesting...
They can get far more complicated..
if your interested, I do my windows programing in Delphi, and one of the TCP/IP systems I use has the demo source for an Eliza server.
its kind of amusing...
http://www.atozed.com/indy/Demos/10/index.en.iwp