[recycledelectron]

I've been saving files since the early 1980's. I've seen a lot of old media die. I've seen executables from a Commodore not run on an XT. I've seen .zip files that opened on an XT not open on a !486, because the format changes. I've seen copy-protected 360k floppies not work in a 1.2MB drive.

I dropped DOC, XLS, MDB, etc when Microsoft moved to DOCX, XLSX, etc because Microsoft's data formats are too ephemeral for long-term use.

Here are my current formats for my 1TB library:

Documents:
PDF
TXT (& CSV)
RTF
CHM
HTM (& HTML)
DJVU (sorry...I had to edit my post to add this)

Databases:
XML

Images:
JPG
GIF
PNG
TIF
BMP

Discs:
ISO, if necessary - otherwise just store the files

Audio:
MP3 (I save them in whatever the encoding is that comes to me, plus I save it as 16 bits per sample, 16k/second, stereo. This is because some MP3 players do not support some formats (for example, 8 bits/sample, 8 k/second, mono.)
CD Audio (rare)

Video: (rare)
AVI
DVD Video

Executables:
x86, on a live disc image

Andy