I have started a project involving my patrilineage, written on a Libre Office spreadsheet for eventual archiving.
I realise that in the far distant future file associations for spreadsheets might well move on. I want to choose one that can be easily opened on most spreadsheet apps and also projects itself forward in time as one that will probably still be useable in a hundred years time, so the data can be subsequently updated. I realise it is a big ask and probably stretching an expert opinion to that of an educated guess. However your guess will probably be a much better one than my own.
The file will be a simple listing of data with no requirement for equations etc.
I have failed to append the drop down “save file type” but I’m sure you know it. My apology for not finding the paperclip