This document discusses library mashups, which combine data from multiple online sources into a single tool. It defines mashups and related terms like APIs and web services. Several mashup tools are described, including Yahoo Pipes, IFTTT, and Fusion Tables. Examples of library mashups are provided, such as integrating ebook searches into catalogs, creating timelines of digital collections, and mashing together multiple library data feeds. Overall benefits of mashups include creating and sharing content more efficiently, providing better services to patrons, and promoting the library.