What is mash-up? What are the features of mash-up? How the interoperability of the mess up works. You will understand such simple and accurate information in this article. Mash-Up is a Web 2.0 app. Mess Up uses data, presentation, and interoperability from two or more sources, and mash-ups it by repackaging it and providing innovation, which gives users more important and simpler information. I want every library and information professional to use mash-ups in the library field.