[undoware]

I cannot recommend https://obsidian.md highly enough.

- Vim-like bindings that don't suck

- Growing and fantastic set of community plugins, including a presently-in-alpha plugin offering Jupyter support (!)

- Markdown-based wiki-type thing, with mobile, sync, and publish support

- Wide range of pleasing themes

- Development is active and is proceeding relatively swiftly; there are new versions available quite often (it's self-updating)

- Electron UI, which I know raises some eyebrows, but in my experience it's comparable to e.g. VSCode in zippiness (so: not terrible, good enough)

Disclosure: I'm working on obsidian plugins, and I paid for a commercial license, but I'm not in any other way associated with the project, i.e. I don't see myself as plugging myself here.

While not FOSS, it's an impressive indie project that I'm enamored with.

[plastic_bag]

Same. Been using Obsidian for a year now and it's been great so far. I use obsidian-git plugin to backup my notes to a private git repository and for syncing notes.

Obsidian's community plugins are awesome!