Technology

I guess I can talk a bit about the first and third points for my personal archiving (certainly not on a global scale).

• For data storage data should be regularly be checked for bitrot and corruption, preferably with a file system that can heal itself if such a situation occurs. Personally I use ZFS RAIDZ with regular scrubs to sure that my data is bitperfect. Disks that regularly show issues are trashed, even if they appear to run fine and show good SMART status. For optical disks in a safe or something I reburn them every ten years or so even if they're still readable to keep the medium fresh.

• I've actually known someone who had to painfully setup a Windows 95 computer in order to convert some old digital pictures from a equally old digital camera stored in a prop format. Obviously that's a no go. For my archives I try to use standard open formats like PNG, PDF, etc. that won't go away for a long time and can be reconverted as part of an archive update if the format starts to become obsolete. You can't just digitally archive everything and expect it to be easily readable after a hundred years. I don't do this but if space is limitless lossless format could be used (PNG for photos, FLAC for audio, etc.) so any conversions remain true to the original capture.