TechnologySoftware used by banks and the space industry may still rely on archaic code. We went in search of the oldest code in use and asked, what happens when it glitches? 5 March 2025 Shutterstock/SkillUpEarlier this year, the technology world welcomed back a long-lost friend. ELIZA, the worlds first artificial intelligence chatbot, had wowed the computer scientists of the mid-1960s with its ability to engage in seemingly meaningful conversation. But, for decades, ELIZA was considered lost because its creator Joseph Weizenbaum at the Massachusetts Institute of Technology never published the 420 lines of code he used to create it.At that time, it was actually kind of not normal to publish code, says Jeffrey Shrager at Stanford University in California. Weizenbaum might even have thought that nobody would find it particularly interesting.How times have changed: Shrager and his colleagues are so fascinated by Weizenbaums achievement that they founded the ELIZA Archaeology Project and began digging into the history of the ancient chatbot. A few years ago, their efforts were rewarded when they discovered the missing code in a box of Weizenbaums old documents at MIT, paving the way for ELIZAs recent resurrection.It is astonishing that we can once again talk to a chatbot that occupies such an important place in the history of AI. It got me wondering: is the ELIZA code the oldest out there, or are there even older snippets of computer code still performing impressive or important tasks? My journey in search of the oldest code took me into the heart of modern operating systems and, figuratively at least, beyond the outer reaches of the solar system. And it revealed something unexpected: this old code, far from being revered like ELIZAs, evokes strangely contradictory attitudes among