[enasterosophes]

Do you mind if I ask what format you've settled on? Having a system evolve over multiple generations means you must have pruned out all the bad ways to do it.

I've got this vision of a Neal Stephenson story which will never be written about a family in the 22nd century that has kept all their personal contacts in Git for over 100 years ...

[froggerexpert]

Consider https://www.gnu.org/software/recutils/

Plain text, but with querying, and likely exporters/importers into calendars.

[westcort]

Thank you! This is interesting!

[westcort]

Grandpa was an early adopter of computers due to his work in cryptography, which started even before WWII. He wrote his files mostly in WordStar, and a few other formats that are still readable. Most of these are on a drive and on 5.25 and 3.5 inch floppy disks. Dad uses KEDIT, and now Notepad++, probably because KEDIT was popular in Princeton at the time. I think John McPhee still uses KEDIT. I use plain text files and HTML.