LibraryThing

LibraryThing is a social cataloging web application for storing and sharing book catalogs and various types of book metadata. It is used by authors, individuals, libraries, and publishers.

Based in Portland, Maine, LibraryThing was developed by Tim Spalding and went live on August 29, 2005. As of December 2015, it has over 2,000,000 users and 100 million books catalogued.