[inigoalonso]

You should definitely check out Tropy: https://tropy.org/

It's open-source, so no worries about a company shutting it down, and it handles a lot of the stuff you're asking for. It’s designed for organizing and managing research photos, but it has features that fit archival needs pretty well.

Open and future-proof: Metadata is stored in JSON-LD, so even if Tropy disappears, your data isn’t locked up. It doesn’t modify your files either, so your originals are safe.

Flexible metadata: You can assign custom dates (even imprecise ones like "circa 1920" or a date range) and add other metadata fields to fit your needs. It’s not tied to EXIF or file timestamps, which is a big plus.

Related files: Tropy lets you group multiple images (e.g., front and back of a photo or parts of a large scanned image) into a single "item." Relationships are preserved, and you can see them all in the same context.

Search and organization: It’s way better than just dumping files into a folder. You get tags, categories, and a solid search interface to make your archive usable.

[jwr]

That is actually a really good suggestion! Thank you, I did not know about this project, and it is quite close to what I'm looking for. Perhaps I won't have to write all of the software myself!

[kaiwenwang]

A good alternative (though paid) is eagle.cool

[jwr]

Red flags: no "pricing" page, I wasn't able to find a price at all. Database doesn't seem to be open.

Perhaps I got the wrong impression, but I do not want to get locked into yet another product that will disappear in a few years.