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 potential benefits of mashups for libraries are provided, such as creating and sharing content more efficiently. The document also outlines considerations for using mashups, like dependencies on external data sources. Finally, it profiles various mashup tools and provides examples of library mashups, such as integrating ebook searches into library catalogs and visualizing library statistics.