Preferably an application that you can sync and save. Not sure what alternatives are safe in terms of privacy and security.
I’m a huge fan of Joplin. It runs on everything and syncs to either your or their cloud. Been using it for a few years now.
2nd for Joplin. Love it to bits. It has its quirks, but they’re ones I can live with. The sync support is pretty awesome.
Been playing with Logseq recently as well. Logseq is more for knowledge management/brain dump kind of notetaking, but it’s really cool that it’s so flexible. It helps that I really like using lists in the first place
Does Joplin have a search function within notes? And it is fully FOSS, yes?
I’m not sure what EXACTLY you’d be looking for from a search feature as I’m mostly a light user myself, but there’s a search option which will search the contents of all your notes. I can’t tell you how robust it is, but it does have exclusion (desiredTerm -excludeTerm) search at least, and there’s standard Find/Replace functionality once you’re in the specific note.
Joplin itself is AGPL. Unfortunately, Joplin Server is under “JOPLIN SERVER PERSONAL USE LICENSE”.
While I really like Joplin, I’m thinking of making the switch to something fully open source.
Cherrytree, no question. You can make hierarchical lists/notes, hyperlink to files, folders, websites and other nodes (lists). You can also insert tables and images in your entries and format text. The whole thing is saved as a single file and you can choose for it to be encrypted if you want. I sync it between devices using Syncthing. Both are FOSS, private and secure. Cherrytree’s UI doesn’t look especially modern but is very effective and you can make your own themes for it in the preferences if you want to glam it up a bit. You can pretty much use it as a wiki for your entire life. In fact, if I could only have one application on my computer it would be this!
NeutriNote CE. It can save and sync to local folders, probably with some external app you can configure it to sync to cloud. It has auto mirror/backup features.
What I like is the way you can navigate through notes and its powerful search function. It also has some extra features which I don’t use. It also has a very detailed manual if you need any help.
org-roam
Markor on Android, MarkText on desktop. I sort notes in category folders and use Syncthing to keep devices… well, synced.