1985, Rheingold, Howard, Tools for thought: the people and ideas behind the next computer revolution, Chapter 11. Computer Book Division/Simon & Schuster. Because he started out young in a field that was young itself, [Alan] Kay was one of the first of the generation of infonauts, the ones who grew up with the tools created by the pioneers, and who have been using them to create a medium for the rest of us.
Source: wiktionary