Yes, ELIZA was Joseph Weizenbaum's original program, from the 1960s, and I guess it had a number of incarnations in MS-DOS and CP/M as DOCTOR and other things. Antonielly mentioned ALICE, at
, by Richard Wallace. Inspired by ELIZA, Wallace developed the AIML system for writing so-called "chatbots," so the possibility exists to create one that speaks Esperanto or any other language. It's a lot of work, of course.
Another chatbot, that works along very different lines, is http://jabberwacky.com
. This one already knows a bit of Esperanto, and many other languages, since it learns from its interlocutors.