The mother of all demos

If personal computing has a single birthday, it very well might be December 19, 1968. That day, Douglas Engelbart took the stage at Brooks Hall in San Francisco to demonstrate the system he and colleagues at the Augmentation Research Center had spent nearly ten years building. They called it NLS, for oNLine System, and over the next 90 minutes Engelbart would reveal just how far they’d progressed.

First, he used something called a “mouse” — which would soon displace that other method of graphical input, the light pen. He showed off WYSIWYG editing with embedded hyperlinks; he combined text with graphics. He speculated about the future of ARPANet, then barely on the horizon of technical possibility, which he believed would soon allow him to demonstrate NLS anywhere in the country. After all, he was already videoconferencing with his colleague behind the scenes in Menlo Park, some 30 miles away.

"We were not just building a tool, we were designing an entire system for working with knowledge."

It became known as “the mother of all demos,” credited with influencing a generation of technologists. Equally important as the technical accomplishments, though, was how Engelbart chose to think about his project. He didn’t want to just offload rote calculations to machines; he wanted to help human beings work in smarter, more effective ways. That day he showed how it could be done. “We weren’t interested in ‘automation’ but in ‘augmentation,’” he said later, “We were not just building a tool, we were designing an entire system for working with knowledge.”

That idea rang true to Alan Kay. To him the increasing power of microprocessors meant a coming, unstoppable revolution: computers the size of hardbound books, available to anyone. He embraced that future with a concept he called the Dynabook; today we’d recognize it as a prototype tablet computer. But getting to a future where anyone could use a computer meant radical change. “If the computer is to be truly ‘personal,’” he later wrote, “adult and child users must be able to get it to perform useful activities without resorting to the services of an expert. Simple tasks must be simple, and complex ones must be possible.”

The Dynabook never became a reality, due in part to technological limitations of the time. Engelbart’s NLS likewise never became a viable system. Unlike Kay, Engelbart embraced complexity. His virtuoso demonstration belied the NLS’s steep learning curve; at one point he told his colleagues it would eventually have fifty thousand instructions. By the early 1970’s, the team he’d assembled at Augmentation Research Center had begun to drift away, many frustrated by the visionary’s inability to let his creation out into the world. They set out on their own adventures.

And many, Alan Kay among them, soon arrived at a new home: Xerox’s just-opened Palo Alto Research Center.