It's remembered as the "Mother of All Demos," and 40 years later, it got another standing ovation.

The man who gave the demo, Douglas Engelbart, was in the audience this time, on Tuesday at Stanford University's Memorial Auditorium, watching a video replay of his Dec. 9, 1968, Fall Joint Computer Conference demonstration of a futuristic computing system, called NLS, or the Online System.

Best remembered as the demo that introduced the world to the computer mouse, it was actually a moment when Engelbart and his team of researchers unveiled a whole new way of computing -- one that looked more like what we do in 2008 than like the punch-card-driven work that was standard back in the 60s.

The mother of all demos, which today feels like a too-long scene in a classic science fiction movie, marked the debut of both hypertext links and on-screen text editing, and it even married computing with video teleconferencing.

Engelbart used video monitors and cameras to mix video with computer-generated images, creating an interface that seems both vintage and futuristic to viewers today. With their faces superimposed over the computer display, team members in San Francisco and Menlo Park talk to each and share files, clicking on words instead of windows. The user interface looks like a primitive version of DOS that somehow works with a mouse.

Those who saw the original demo and understood Engelbart's vision were blown away. "My heart was in my mouth the whole time," remembers Tom Hagan, CEO of Actioneer. Two years later, the company he worked for had bought Computer Displays Inc. (CDI), the company that sold the first mouse, as part of its ARDS (Advanced Remote Display System) computer.

Hagan had the world's first commercially produced mouse on hand and was showing it to all comers during a break at the Stanford event. Beige and clunky, with three ergonomically unfriendly buttons, it was about the size of five iPhones. On the back: CDI Serial Number 001.

Logitec co-founder Daniel Borel was on hand to commemorate his company's sale of its 1 billionth mouse.

In the video from 1968, before starting his demo Engelbart briefly describes his vision of computing. "If, in your office, you, as an intellectual worker, were supplied with a computer display backed up by a computer that was alive for you all day and was instantly ... responsive to every action that you had, how much value could you derive from that?" he asks.