CrypticShift
Grist [1] desktop [2] is a (kind of) local "wrapper app" over an sqlite database. It is "As extendible as it is flexible" [3]

The problem is I feel the tabular DB format is "too raw" for some usecases. I prefer Outliner/DB combos (like the upcoming logseq DB version) or maybe one of the local Notion alternatives.

[1] https://github.com/gristlabs/grist-core [2] https://github.com/gristlabs/grist-desktop [3] https://www.getgrist.com/product/#:~:text=As%20extendible%20...

evanjrowley
I'm looking for the same. Open source, self hosted, and end-to-end encrypted.

I haven't found anything that really does all of this, but it seems like Cryptpad[0] and Peergos[1] are viable platforms upon which something like this could be built.

Except for the lack of encryption, Atomic Data[2] also seems like a really cool platform to build this on.

[0] https://cryptpad.org/

[1] https://peergos.org/

[2] https://github.com/atomicdata-dev/atomic-server

PaulHoule
It's a topic I have on my mind.

Right now I have a system I call FRAxInUS which uses a document database back end and contains a commenting system, tag system, personal webcrawler, and has some visualization tools. It started out reusing a lot of code from my YOShInOn RSS reader and one of these days I want to make YOShInOn a FRAxInUS application.

In one instance of this I have a collection of 250,000 or so images or so which I am organizing. In the other one I loaded about 400 notes from somebody's Evernote and I am tagging them. I'm planning to introduce "projects" to the system so I could go to a URL like

/projects/b12f2df5-0eda-436a-9776-04221488f744

and this goes to a "tenant" in the system which might have its own db or might be in a shared db with records marked with the project id and also activates a set of Flask blueprints and sets template settings to personalize it. It starts out with ingesting images, HTML, and plain text but the long term plan is to implement structured records, for instance, to have a semiautomated process to suck out references to people in the notes and make a database of people.

Look up my email in profile and I'd be glad to talk about it.

Rochus
Have a look at https://github.com/rochus-keller/crossline/. I use it for the mentioned purpose (besides Cycling/GPX) since more than a decade. Originally I used Netmanage Ecco, which was discontinued and didn't support all features I needed (i.e. cross-references, more than one outline, etc.). It has an integrated database using the SQLite backend on top of which I implemented a kind of object database (extended entity-value). It's written in C++ and "hackable".
jjice
This may not be the solution you're looking for, but I've found that I've really liked plain text files with some machine readable parts.

One thing I've done is a new line staring with a colon represents metadata, like

    :tags customer,product2
And I've built tools around tag searching. Same thing goes with dates and other misc metadata I may want to use.

It may not be what you're looking for, but I've found it to be a good middle ground for myself.

runjake
I'd start with SQLite3 and go from there. Everything and anything has hooks for it.
tacostakohashi
Sounds a bit like a bunch of files in some directories.