Douglas Engelbart gave what became known as "The Mother of All Demos", publicly debuting the computer mouse, hypertext, and the bit-mapped graphical user interface using the oN-Line System (NLS).

Douglas Engelbart
Douglas Carl Engelbart was an American engineer, inventor, and a pioneer in many aspects of computer science. He is best known for his work on founding the field of human–computer interaction, particularly while at his Augmentation Research Center Lab in SRI International, which resulted in creation of the computer mouse, and the development of hypertext, networked computers, and precursors to graphical user interfaces. These were demonstrated at The Mother of All Demos in 1968. Engelbart's law, the observation that the intrinsic rate of human performance is exponential, is named after him.
The Mother of All Demos
"The Mother of All Demos" was a landmark computer demonstration, named retroactively, of developments by Stanford Research Institute's Augmentation Research Center. It was presented at the Association for Computing Machinery / Institute of Electrical and Electronics Engineers (ACM/IEEE)—Computer Society's Fall Joint Computer Conference in San Francisco, by Douglas Engelbart, on December 9, 1968.
Computer mouse
A computer mouse is a hand-held pointing device that detects two-dimensional motion relative to a surface. This motion is typically translated into the motion of the pointer on a display, which allows a smooth control of the graphical user interface of a computer.
Hypertext
Hypertext is text displayed on a computer display or other electronic devices with references (hyperlinks) to other text that the reader can immediately access. Hypertext documents are interconnected by hyperlinks, which are typically activated by a mouse click, keypress set, or screen touch. Apart from text, the term "hypertext" is also sometimes used to describe tables, images, and other presentational materials with integrated hyperlinks. Hypertext is one of the key underlying concepts of the World Wide Web, where Web pages are often written in the Hypertext Markup Language (HTML). As implemented on the Web, hypertext enables the easy-to-use publication of information over the Internet.