Lars Brinkhoff brought up PARRY, Kenneth Colby's 1972 paranoid chatbot, and Rupert Lane, who recently reanimated the original ELIZA, was able to (sort of) reproduce the famous RFC439 trans-internet conversation between ELIZA and PARRY. See the blog post for the amazing (and amusing) details! (Turns out that RFC439 used a Lisp ELIZA, not the MAD-SLIP original.)