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Microsoft develops ultra durable glass plates that can store several TBs of data for 10000 years
(unlocked.microsoft.com)
This is a most excellent place for technology news and articles.
I don't have anything I can't open and I've got stuff from 20+ years ago. I don't even have to go out of my way to have applications that are compatible with it. If I did run across something I would just build a VM with whatever software I needed to open it. Just have to keep in mind what software you'll need and back that up as well.