You can borrow online books from them for a few hours/days: This is the most amazing thing ever made!!! You can even link to specific pages, e.g.
They seem to a have a separate URL with the same content as well for some reason:, classic messy Internet Archive style.
Bastards are suing them Hachette, Penguin Random House, Wiley, and HarperCollins
It is quite hard to decide if an upload is from the official legal lending library, or just some illegal upload, e.g.:so the URLs are basically the same style. Some legality indicators: says 15 archives / minute, but apparently aslo 15 retrievals per minutes on Wikipedia, after which 5 min blacklist. After that, you start getting some 429s, and after that, server refuses to connect at al.
CDX: no limits apparently, they might just throttle you? Made 10k requets on bash loop and was going fine. But not that if you get blacklisted by create/fetch requests blacklist, server fails to connect here as well.