The document discusses mashups and widgets. It defines mashups as combinations of content from multiple sources and describes different types of mashups, including music, videos, and web applications. It then introduces the concept of the "mashup pyramid" which categorizes tools for creating mashups from high-level graphical tools to low-level platforms and APIs. The document also defines widgets as single-function applications and discusses different types of desktop, web, mobile, and physical widgets. It provides steps for creating a basic RSS widget and discusses widget packaging formats.