On December 21, 2024, shortly before 2 p.m., scientists made the dead speak. ELIZA, the first chatbot in the world is back. Long imitated, but not perfectly replicated, ELIZA was long considered lost. But scientists discovered an early version of its code in the archives of its creator in 2021 and spent the intervening years piecing it together.
ELIZA is reanimated and you can download it here to see for yourself.
Coded and repeated from 1964 to 1967, ELIZA was developed by computer scientist Joseph Weizenbaum of MIT. Rudimentary by today’s standards, ELIZA was a hit at the time of its creation. He gave him the persona of a psychotherapist, and his secretary was so charmed by him that she asked Weizenbaum to leave the room while she spoke with him.
AND new scientific work from the members of the ELIZA Archaeological Project describes in detail how they found and resurrected the chatbot as well as its origin and subsequent spread. Weizenbaum programmed ELIZA in an early language called MAD-SLIP on a computer time-sharing system called the Compatible Time-Sharing System, or CTSS.
ELIZA quickly ran away from Weizenbaum. As it spread through early computer networks, programmers adapted it to other languages. One of these early clones was built in Lisp by one of the technical leaders of the ARPAnet, the forerunner of the modern Internet. The Lisp version of Eliza was one of the first data on this fledgling network and spread quickly.
“As a result, Cosell’s Lisp ELIZA quickly became the dominant strain, and Weizenbaum’s MAD-SLIP version, invisible to the ARPAnet, was consigned to history,” the paper said. “Until it was rediscovered in 2021, the original MAD-SLIP ELIZA had not been seen for at least 50 years.”
A decade later, Creative Computing magazine published an ELIZA clone written in BASIC. It was 1977, the same year the Apple II, Commodore Pet and TRS-80 hit the market. These machines led to the explosion of home computing and the spread of the BASIC computer language.
“And probably not a small number of those hobbyists who were interested enough in the possibility of artificial intelligence to type in this BASIC ELIZA (which was just a few pages of code) and experiment with it themselves,” the scientists said. “Because of its brevity and simplicity, and the personal computer explosion, this ELIZA spawned hundreds of copies over the decades, in every imaginable programming language, making it perhaps the sweetest program in history/ Just as Cosell’s Lisp ELIZA spread over the ARPAnet, BASIC ELIZA spread through an explosive infection of personal computers.”
There are currently countless versions of this BASIC version of ELIZE online, and the original MAD-SLIP version has long been considered lost to history. Then Stanford computer scientist Jeff Shrager convinced MIT archivists to examine the boxes of Weizenbaum’s material, and they made a critical discovery: early versions of the MAD-SLIP code.
The code was unfinished and it took a lot of tinkering and complicated emulation to get it working again. “This required numerous steps of cleaning and completing the code, installing and debugging the emulator stack, non-trivial debugging of the found code itself, and even writing some completely new functions that were not found in the archives or in the available MAD and SLIP implementations,” the paper writes.
It took time and a lot of effort, but the code archaeologists have rebooted ELIZA and made it available for everyone to play. “This has been tested on various versions of Linux and MacOS, but we’ve noticed some issues with different versions, so your mileage may vary,” the paper said. “If you run it on your machine and find you need to change something, please let us know.”