Well, GNU Emacs came after other Emacs implementations which had namespaces, threads and closures. For example Zmacs on the Lisp Machine had all that. It was wr

Well, GNU Emacs came after other Emacs implementations which had namespaces, threads and closures. For example Zmacs on the Lisp Machine had all that. It was written in Lisp Machine Lisp (aka Zetalisp). Richard Stallman had used it and contributed to it. So GNU Emacs would borrow from ideas older than its implementation.