[jjav]

> My MP3 collection has been going on for at least 25 years and still works perfectly.

Mine as well (maybe not quite 25 but close). But music isn't written word, clearly it wouldn't be in an ASCII text file.

The key is universal, non-proprietary formats that are supported by thousands of open source applications. Those are the formats that will last a lifetime and beyond. So, plain text for the written word (HTML counts as plain text, you can read and write it in any plain text editor), JPG for pictures, MP3 for music.

For video there doesn't seem to be an answer that is fully satisfactory, that I feel confident I can still view in 50 years. So I mostly take photos, not much video, since I can't trust the longevity of video.