The document discusses Karen Coombs' real-life experiences using various library APIs to solve problems integrating library data into websites and applications. Some APIs discussed include the WorldCat Search API, WorldCat in FCKEditor, WorldCat Search Widget for Wordpress, WorldCat Search API Google Map, xISSN TOC Lookup, WorldCat Registry, and Libraries Nearby. Some challenges mentioned are having the necessary data like ISBN or geo coordinates, choosing an appropriate metadata format, and using XPath queries.