Wonder why no one has mentioned lilypond so far.

Ohh, I love pandoc!!

OMG, are you me? I’m also a heavy stack* and ask* user, that’s so funny!

I’m not sure if it really uses single file, I’m a relatively new user and while linking around the system, saw that it saves its stuff in a single … what was it… gz or zip or tug. But not sure if it just scrapes everything and puts it into an archive file.

If you use the browser extension, it saves the page as rendered (at least it should). If not, open a bug report, the maintainer seems quite helpful.

You can also somehow script extractors I believe, so it should be possible to correct saving ask* and stack* pages.

Hey, my nick! I’m not 100% sure but readeck saves into a single file.

You’re looking for a block level incremental backup solution. This can either be achieved using filesystem based snapshots (ZFS, BRRFS) or using dedicated programs. I know rdiff-backup , restic and duplicity use block-level diffs, not sure about rsnapshot.