Zine is short for magazine, I think. Offline zines are often self-published paper booklets, produced by lone wolves or communities, with a focus on one subject. Digital zines are often PDFs. Sometimes a printable booklet version is provided so they can be printed and distributed. Here's an example of a digital zine: https://digitalselfdefence.net/pdf/dsdc-zine.pdf

Better, they make zines! https://jvns.ca/

I found this the other day. It's Linux first, but not FOSS. Flatpak version is pretty sweet. https://indomitusgroup.com/indipdf/