The document discusses Yahoo Application Platform (YAP) which allows developers to build web applications that are distributed by Yahoo. It provides instructions on converting a basic web application into a YAP application, including removing blacklisted tags, making CSS and JavaScript inline, and ensuring it passes the Caja sanitization process. Examples are given of a Flickr photo application and a YouTube video application built as YAP apps. Caveats of the YAP platform are also outlined.