I use evil-mode in emacs. I've used the distributions Spacemacs and Doom so far that are focussed on evil mode.
This page talks about some of the emacs packages I use.
This service running on emacs along with a browser add-on can make any text box in the browser editable through emacs.
I am writing this page from emacs using GhostEdit plugin for Firefox which talks to the atomic-chrome server running from emacs. There doesn't seem to be a mediawiki-mode exposed by mediawiki.el, so I cannot actually use help from emacs when writing using MediaWiki syntax.