Vi Turns 50: The True History of vi

Most sources just say "started development in 1976".

The Joy of Unix

Sun Microsystems co-founder Bill Joy charts where Linux and free software fit into his company's solar system.

by Eugene Eric Kim

https://web.archive.org/web/20000303115338/http://www.linux-...

https://www.linfo.org/vi/history.html

https://world.hey.com/dhh/wonderful-vi-a1d034d3

https://en.wikipedia.org/wiki/Vi_(text_editor)

[from ‘Visual Interface’] A screen editor crufted together by Bill Joy for an early BSD release. Became the de facto standard Unix editor and a nearly undisputed hacker favorite outside of MIT until the rise of EMACS after about 1984. Tends to frustrate new users no end, as it will neither take commands while expecting input text nor vice versa, and the default setup on older versions provides no indication of which mode the editor is in (years ago, a correspondent reported that he has often heard the editor's name pronounced /vi:l/; there is now a vi clone named vile). Nevertheless vi (and variants such as vim and elvis) is still widely used (about half the respondents in a 1991 Usenet poll preferred it), and even EMACS fans often resort to it as a mail editor and for small editing jobs (mainly because it starts up faster than the bulkier versions of EMACS). See holy wars.

http://www.catb.org/jargon/html/V/vi.html