
Researchers have successfully resurrected ELIZA, the world’s first chatbot, from 60-year-old computer code. This discovery has significant implications for artificial intelligence and natural language processing. The chatbot was developed in the 1960s by MIT professor Joseph Weizenbaum and was designed to simulate conversation using pattern matching and substitution techniques.
ELIZA, the first-ever chatbot created in the 1960s, has been brought back to life by scientists using long-lost computer code. This incredible revival showcases the early days of artificial intelligence and highlights its continued relevance.
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Developed by MIT professor Joseph Weizenbaum, ELIZA was named after Eliza Doolittle from the play Pygmalion. The chatbot simulated conversations, famously mimicking a psychotherapist. For example, it would ask, “Please tell me your problem,” and respond in ways that encourage users to keep talking. While modern chatbots are far more advanced, ELIZA’s focus on listening was unique and remains noteworthy.
The program was originally written in a programming language invented by Weizenbaum called MAD-SLIP, but it was later converted into Lisp, which made it widely accessible. With the rise of the internet, the Lisp version became popular, and the original code faded into obscurity.

In 2021, researchers Jeff Shrager from Stanford University and Myles Crowley from MIT rediscovered the original 420-line code in Weizenbaum’s archived papers. Using printouts from the 1960s, the team restored the program. Moreover, he also successfully ran it on an emulated 1960s computer system on December 21, 2024.
Shrager described this effort as “software archaeology,” emphasizing the importance of preserving the history of early computing. The restoration revealed a small bug in the code, which the team chose not to fix to maintain its authenticity.
David Berry, a digital humanities professor, compared ELIZA’s revival to preserving cultural artifacts like the Mona Lisa. He stressed that computing history is also cultural history and deserves preservation.

ELIZA’s resurrection highlights the importance of remembering how AI started. Even though it lacks the sophistication of today’s models like ChatGPT, ELIZA remains a landmark achievement. In addition, it also reminds us of the roots of human-computer interaction.