ELIZA is a natural language conversation program described by Joseph Weizenbaum in January 1966 [1].
It features the dialog between a human user and a computer program representing a mock Rogerian psychotherapist.
The original program was implemented on the IBM 7094 of the Project MAC time-sharing system at MIT and was written in MAD-SLIP.

For a conversation example given by Joseph Weizenbaum in his article see the Eliza Test page.