In a word, VMs. If you make sure you can open that NEF or CR2 file in a virtual machine, and the virtual machine image is in a standard, open format, you're set

In a word, VMs. If you make sure you can open that NEF or CR2 file in a virtual machine, and the virtual machine image is in a standard, open format, you're set. You just have to worry about the image format becoming obsolete and not 10 or 20 different proprietary formats. That said, I used to be a pretty prolific hobbyist musician and I haven't pulled this off myself. I have tons of old songs I can't open because they rely on a fiddly collection of old freeware plugins for freeware music apps from 11 years ago. I also have songs I can't open because they only play in a music tracker I wrote, which is open-source, but only runs on OpenBSD. It is a tricky problem and it seems hard to tackle because the market for professional software inherently favors closed-source, which has no incentive to adopt open, non-siloed formats.