I can recommend Notesnook.
Relatively cheap premium plan, everything is open source, with clients available on F-Droid and Flatpak and end-to-end encryption.
For server code they already published the source. Option to use self-hosted servers is on the roadmap: https://notesnook.com/roadmap/
I went down the rabbit hole of an open source replacement for notion earlier today randomly.
Any suggestions?
Obsidian is very solid and has a huge addon eco system to change it most ways you might thino of.
and it’s not open source.
I believe Logseq is the closest thing there is to an open source alternative to Obsidian.
I can recommend Notesnook. Relatively cheap premium plan, everything is open source, with clients available on F-Droid and Flatpak and end-to-end encryption.
For server code they already published the source. Option to use self-hosted servers is on the roadmap: https://notesnook.com/roadmap/