All ZIMs created by Kiwix: https://download.kiwix.org/zim/
Note that you can get a torrent file by just appending .torrent to the URL. And if you remove the date from the URL it will redirect to the newest one.
You can also create your own ZIMs of course. For example with zimwriterfs you can create a ZIM from a folder you have downloaded.
Kiwix reader software targets HTML but ZIMs can hold anything.
Sunbeam City is a anticapitalist, antifascist solarpunk instance that is run collectively.