I’ve been using Obsidian lately. Proprietary with an open plugin ecosystem. Works well, makes it easy for me to integrate with other notes and such, but I haven’t figured out a good workflow for exporting work for submission. That said, it’s all markdown and there are lots of plugins for stuff like that, so it’s probably mostly just that I haven’t tried very hard.

In the past I’ve used Google Docs (proprietary), Scrivener (proprietary), Manuskript (open), Zim (open), and probably a few I’m forgetting. Really it just comes down to what you’re looking for out of the software, there are lots of options.

The biggest thing to keep in mind from a self-hosting perspective is local storage and easy backups under your own control. I use syncthing to keep my whole Obsidian vault synced across a few devices; for some software that’s easier or harder due to file formats and accessibility.

I don’t write books but I’ve helped written a couple textbooks which used LaTeX. I personally use TeXstudio, but there’s many clients out there. If you appreciate beautiful typesetting, you’ll likely enjoy TeX despite its learning curve.

https://www.literatureandlatte.com/scrivener/overview it’s proprietary, but it has a lot of features geared towards writing novels/screenplays/etc

I take the approach of doing content first and styling second. For content I don’t need anything more sophisticated than a plain text editor. I like it because it removes decisions that I really don’t need to be making at that point.

Check affine.pro it’s really flexible. Some features might seem overkill. But I think that the flexibility might pay off in some situations (e.g. adding drawings, having character profiles in separate docs, add location maps, etc.)

It’s a local-first alternative to Notion. Just a few months ago they added export to pdf (there’s markdown too, of course) https://github.com/toeverything/AFFiNE/pull/2604

I don’t write novels, but lately found apostrophe (gnome) and ghostwriter (KDE) which are intended to write using markdown, and have a UI intended to allow you to focus on writing. You can later use git to manage versions and backups (in a remote repository).

If you want something more focused on relationships, and regarding the answer from another user suggesting Obsidian, you might use also logseq, but I didn’t use it yet (but hear a lot of positive vibes around it).

I have just started, and decided to use Mkdocs for my personal notes, journaling, and a budding novel that kept buzzing around in my head and wants out. In the moment I just throw titles, links, citations and bits of text in a document, later I hope to be able to sort through the mess and separate into chapters. Let’s see. I’ve connected it to a git repository on codeberg for backup. I did this because I like to write in Markup and decided to use the same setup to create a static page for my business (with My Webapp on Yunohost to serve). Then I just kept the same for my notes. I like super simple folder based setups without too many bells and whistles cause I find them distracting. Focuswriter on the other hand was too basic without the ability to create links between files.

I recently saw a blogpost somewhere, where someone used git versioning for writing, and I find this idea highly intriguing. Then I realized, that I already have an app that would allow me to work like this: NotesHub

For now, I only started a journal, but I plan for some time already to start writing again.

Obsidian is great too, but a pain when it comes to syncing on iOS.