On 9 December 1968, in San Francisco, during a computing conference, Douglas Engelbart went on stage with a keyboard, an odd device with a cord, and a screen projected behind him. Over the next ninety minutes or so he showed the audience the mouse, hypertext links, on-screen text editing, the division of the screen into areas, and remote collaboration with video and audio. That presentation has gone down in history as "the mother of all demos".
Who Engelbart was
Douglas Engelbart was an engineer who had served as a radar technician during the war. He recalled reading, in that period, As We May Think, Vannevar Bush's 1945 article that imagined the Memex, a desk able to store documents and link them together with "associative trails".
In the 1950s Engelbart came to a conviction: the world's problems were growing ever more complex, and computers could serve not so much to replace human thought as to augment it. In 1962, at the Stanford Research Institute (SRI), he wrote a report entitled Augmenting Human Intellect: A Conceptual Framework, which set out this research programme.
With funding from government agencies, including ARPA, he founded the Augmentation Research Center at SRI.
The mouse
One of the problems to solve looked trivial: how do you point to a spot on the screen? Engelbart's group compared several devices, including the light pen, the joystick and other pointing systems.
The prototype mouse was built by the engineer Bill English, from Engelbart's idea, around 1964. It was a small wooden box with a button and, underneath, two perpendicular wheels: one recorded horizontal movement, the other vertical. The cord came out of the back like a tail, and the name "mouse" arose informally within the group.
The patent, filed in 1967 and granted in 1970, described it with a far less charming name: an X-Y position indicator for a display system.
In the group's tests the mouse proved faster and more accurate than the alternatives for selecting items on screen.
NLS: the system behind the demo
The mouse was only one part. The real subject of the demonstration was NLS (oN-Line System), a system for creating, organising and linking information interactively. During the presentation Engelbart showed:
- On-screen text editing: inserting, deleting and moving words and paragraphs, seeing the result immediately.
- Hierarchical organisation: documents were structured as outlines, which could be expanded or collapsed to show more or less detail.
- Hypertext links: selecting a reference took you straight to the linked content.
- Windows: the screen could be divided into areas with different content.
- Real-time collaboration: a colleague, tens of kilometres away in the Menlo Park laboratory, worked on the same document, with a video link visible in a corner of the screen.
- The chord keyset: a five-key device, used with the left hand, that allowed commands to be entered by combining keys while the right hand used the mouse.
How it was done
The demonstration was a technical feat. The computer was at SRI, in Menlo Park, and the video signal was transmitted to the hall in San Francisco over microwave links, while the mouse and keyboard signals travelled the other way. The image was projected onto a large screen for the audience. Bill English directed the broadcast.
Reception and influence
Many of those present were impressed, but Engelbart's ideas were not adopted straight away. The system was complex, required considerable training and was tied to extremely expensive hardware.
The influence, however, was deep and direct. Several members of Engelbart's group moved in the 1970s to Xerox PARC, where they helped develop the Alto and the graphical interfaces that would inspire the Macintosh and Windows. The mouse came into common use only in the 1980s, with the spread of graphical interfaces.
What it really showed
It is useful to distinguish between what Engelbart invented and what he was the first to show in an integrated way. Hypertext as a concept had already been discussed by Ted Nelson, who coined the term in the mid-1960s. Engelbart's unique contribution was to bring everything together in a working system and to use it in front of an audience, proving that a completely different way of working with computers was possible.
In 1997 Engelbart received the Turing Award. He died in 2013.
A lesson for today
Software designers can draw from this story a principle that still holds: the purpose of a computing tool is to make people more capable, not merely to automate tasks. Many features we now consider normal, such as collaborative editing of shared documents or video calls while working on a file, were already present, in embryonic form, in that 1968 demonstration.
In short
- On 9 December 1968 Douglas Engelbart presented the NLS system in San Francisco in a demonstration lasting about ninety minutes.
- The mouse, built by Bill English from Engelbart's idea, was a wooden box with two perpendicular wheels.
- The demo showed on-screen editing, hypertext, windows and real-time collaboration with video.
- Many of Engelbart's colleagues later moved to Xerox PARC, where modern graphical interfaces were born.
