The Dynabook
Alan Kay's 1972 vision of a personal, dynamic computer-as-medium for children of all ages.
In 1972 Alan Kay described "A Personal Computer for Children of All Ages" — a notebook-sized, networked device with a crisp display and a dynamic programming environment, owned by the user, on which they could create and not merely consume. He called it the Dynabook.
The hardware looks, in retrospect, like a prophecy of the laptop and tablet. But Kay insists the prophecy has only half come true. The Dynabook was never primarily about portability; it was about the computer as a medium — like paper or film — that an ordinary person could author in, fluently, to think new kinds of thoughts. A tablet that mostly plays video is, to Kay, a Dynabook that forgot its purpose.
The Dynabook drove the work at Xerox PARC that produced Smalltalk, overlapping windows, and the modern GUI. Read The Dynabook That Never Was.