Zim is a graphical text editor and personal wiki that can be used as a personal knowledge base or notebook. Pages are stored locally in a folder structure in plaintext. Zim is available on Linux, macOS, and Windows.
Why I think this tool should be added
Privacy Guides currently doesn’t recommend any local knowledge base tools except Org-mode for Emacs which isn’t really ideal for non-programmers or anyone who doesn’t use Emacs. Zim is fully graphical and user-friendly but is still lightweight and doesn’t use Electron (all of the recommended cloud-based notebooks with desktop apps do).
Zim is open source and supports exporting documents into HTML, Markdown, and other formats. The rest of the minimum criteria doesn’t apply since Zim doesn’t support cloud sync.
Although some of the cloud-based notebooks PG currently recommends may work offline, I still think offline-only notebooks should be recommended for those who prefer not to have cloud sync at all. As aformentioned, all of the cloud recommendations either use Electron or are web-only and there are plenty of reasons to avoid Electron like security issues and bloat issues.
I’m using Zim, syncing files via syncthing, so don’t care about E2EE. There is no Android app, but Markor can work with those a bit. I don’t write notes on my phone, only read, so I don’t care about missing features.
I’ve tried and used many different notebooks over the years (OneNote, Standard Notes, Joplin, Obsidian, Zettlr, CherryTree, QOwnNotes…) and have realized that Zim is the one that suits me best.
The only downside I have with Zim other than no E2EE (which again isn’t a dealbreaker) is it uses it’s own obscure format for editing instead of using markdown which isn’t a dealbreaker but requires a bit of learning, and files can be exported to different formats.