I had already seen it around on various sites, but my machine's fast enough that I wasn't waiting long enough to check out what it was. I think there's other implementations of the same idea, but I think this one's the standard now.
It becomes quite difficult nowadays to bookmark webpages or archive them, with CF, BotStopper/Anubis, Go Away etc... we will just need to all burn more cpu power just to access good content.
https://farside.link/redlib/