They are common here. Membership is usually a dollar or two a month. Members store their books their on a kind of permanent loan so they don’t have to store so

They are common here. Membership is usually a dollar or two a month. Members store their books their on a kind of permanent loan so they don’t have to store so many books in their house. It’s unstaffed and just run by its members, and members replace any books they lose. There is a private engineering library I visited in TN (anyone can drop in during business hours) that aims to preserve books that engineers used before everything became computer assisted.