Two bots talk to each other: Two students of mine, Meabh Landers and David Cullen, write a scambot-detecting bot, "policewoman".
It responds to requests to webcam and requests for credit card info by trying to detect if the other side is human.
It ran on a VAX/VMS mainframe (to be precise, the machine: ) that Computer Science students and staff at UCD shared.
To really test the program, it was necessary (a) to introduce surprise, and (b) for it to talk to strangers.
In 1989, in the final year of my undergraduate course, I put this program online, and now for the first time it had the element of surprise, and it could talk to strangers long-distance.
The conversations this program had can be seen - depending on how one defines the rules (and how seriously one takes the idea of the test itself) - as a passing of the Turing Test.
This is the first time this event has been properly written up. This was certainly one of the first AI programs online.