This is the Openbare Bibliotheek in the Centrum, just east of the Centraal Station. It’s the home of the Amsterdam “public” library. Your membership fee (€25.50/year, 50 cent drop-off fee to a different branch from that which you rented and €1 reservation fees for transferring books and of course €2 for videos or CDs) goes to help pay for the amazing architecture, designer lighting, chairs, automated book return system and of course, the fancy computer stations. Oh, and over 1.7 million books!!
The metal things hanging from the shelf are the book ends.
You can slide them along the entire length of the shelf. Most effective book holders I’ve seen.