With ongoing weridness on access to internet information I've started (probably a bit late) to backup offline copies of stuff and wondered if folks had any other recommendations or a checklist of info to get as part of a personal archive?

Offline Copies I've got so far include:
>wikipedia other wikis
>Project Gutenberg
>Subject Textbooks
>IFixit guides
>Medical textbooks

If anyone has any other recommendations of texts / software / documents that might be good to get I would be interested to hear