An extremely late response, I'm sorry, but: I think you are asking the wrong question here. Instead of asking "would people be interested in the protocol", ask "would people be interested in *what can be done because Emacs supports* the protocol".

Beyond that, it might be a fun hack to add, but brings no real value; the benefits come from the capabilities it brings.

(I also agree with 2017 RMS on the correct location for it.)

On Tue, Dec 18, 2018 at 7:07 PM Eric Lindblad <lindblad@gmx.com> wrote:

Do you think GNU Emacs users would be interested in using 9P protocol from within the editor, implying an Emacs Lisp 9P Client/Server might be authored?

http://9p.cat-v.org/implementations

The 9p.scm (client) hyperlink in the above URL is dead, and it has a new home at the below URL.

http://nurmi-labs.blogspot.com/p/9p-scheme.html

Maybe other GNU Emacs users have another opinion to that of R. Stallman's (circa 2017) response which is reproduced below.

"It makes no sense to put this feature into Emacs, which is the wrong place for it. The right place for it is in the kernel (Linux or the Hurd), so that all the application programs will be able to use it."