There's a megathread on r/programming about the Gosling/Stallman legal fight, but long story short, the GNU Emacs we know today was continuously built upon a foundation first laid down by Jim Blandy and Stallman. Very little, if any, code from Gosling, Moon, or Steele survives.
But GNU Emacs was not the first incarnation. That was EMACS on some PDP system in the 70s and Richard Stallman was already involved in that. Gosling Emacs only came years later.
[–] moishe_syzslak 1 day ago
[–] steve1977 21 hours ago