Edit with Emacs is an addon for webextension compatible browsers
like Google's Chrome(ium), Opera or Firefox that allows you to edit
text areas on your browser in a more full featured editor. It does
this in conjunction with an "Edit Server" which services requests by
the browser. This is because extensions cannot spawn new processes
as a security measure.
The extension packages a native elisp version that can be run inside
GNU Emacs itself.