Like many (most?) Emacs users, I do all my writing with Emacs. This mostly involves Org-mode but even when it doesn’t I’m still in some sort of Emacs buffer. I just came across this old Stack Exchange post asking about Emacs configurations for creative writing.
If you’re looking for an excellent writing tool, you should check out this thread. Also be sure to follow the link to Randall Wood’s Woodnotes Guide to Emacs for Writers. It covers those aspects of Emacs most likely to be useful to writers. Wood doesn’t consider coding at all, only creative writing.
I know many writers like tools such as Scrivener for organizing their writing. While I’ve never used any of those special tools—let alone the horror that is Word—I find it hard to believe that an appropriately configured Emacs is not equally good or better. One of the nice things about writing with Emacs and Org-mode or Markdown is that you can export to Word format with Pandoc or Org’s export engine. That’s really handy because you can write with a decent editor and still provide your publisher with the Word document that most publishers insist upon.
It’s an interesting thread. If you do any writing, especially creative writing, you should check it out.
Update: Randal → Randall