I have been using Bookstack, I like it though it is missing a few features I would love:

• you cannot insert a video in it
• there is no possibility to comment on a particular text
• the permissions management is only done with roles. That's fine generally but I wanted to be able to share a specific page with a specific user, and for that I had to basically create a dedicated role for this use.

Mediawiki

Fossil-scm.org is very lightweight (2mb ram) and does quite a lot. See if you like it.

Dokuwiki doesn't have to look old, it is only the default theme that does. Just install a nicer theme and the Prosemirror addon and it looks and functions like any other modern wiki.

I've been using silverbullet.md

Its more notes than wiki I guess so depends what you're after.

I needed something dead-simple to keep homelab documentation. If it's not simple, I probably wouldn't keep up with changes. I landed on An Otter Wiki https://github.com/redimp/otterwiki

Using dokuwiki, just cut the cheese for me.

Its "old" because it uses php, but its quite solid and doesn't need a database, so all plus to me.

There are cool and modern looking themes too.

I use https://mycorrhiza.wiki/ it is not very fancy but it is a single executable file and stores pages in a git repository, so no database is needed and doing the export is as simple as reading some files.

It's apparently early in development, but there's an ActivityPub implementation of wikis made by one of Lemmy's dev.

Mkdocs fits your criteria imo. But if you want something more customizable, you could use the astro.build docs template

It doesn't cover permissions unless you are willing to setup http auth on your webserver but I really enjoy mdbooks. I looks clean and still is just markdown.

I use gitit and it's already packaged in most Linux distros.

DokuWiki has themes. I've been using the bootstrap theme which is super old but at least does not look like the ugly default theme. You can find my wiki here.

I didn't find anything similarly lightweight yet apart from static site generators with Markdown files or ASCIIDoc.

Something like wiki.js might also be worth a look.

@SexualPolytope

For a long time I’ve used https://tiddlywiki.com/ for tracking details and notes while working on projects.

#wiki

I use markdown files in git + mkdocs with a post-commit build and push step. You could also try lektor.

I use tiddlywiki for my single-user wiki. The setup is dead simple, one html file on your computer you open directly. There is also a nodejs server implementation, which I use.

Trilium. Share the nodes in the tree that you want public.

You said you liked the look of wiki.js but didn't say what you didn't like (unless I was missed it). Why not just use wiki.js? If you want permissions you'll likely end up with other features like editing too.

For what's worth Wordpress can work as a wiki with a wiki theme like this one. Modern standards dictate that it's light... doesn't consume resources when not in use and it's easy to install and manage.