Hmm, this other 1979-era history of Emacs also doesn't mention Steele, though it does mention Weinreb and Moon, whom the author seems to have worked with closely: http://www.multicians.org/mepap.html.

That's a wonderfully interesting article.

Steele was one of the authors of the TMACS package, for which this article has “???” in the references.

Incidentally, the article mentions Multics' version of QED in passing; this regular-expression-based editor was written by Ken Thompson¹ and is a (more complicated) ancestor of ed(1), the standard text editor on Unix.

¹ http://cm.bell-labs.com/cm/cs/who/dmr/qed.html

I heard this history from an eyewitness in, oh, about 1981 plus or minus a year, long before RMS forked Gosling Emacs for his GNU Emacs.

None of the three other listed AI Lab names ever had anything to do with these C/UNIX(TM) versions of EMACS.