Mashups: The new breed of Web app

Mashups: The new breed of Web app: "Mashups are an exciting genre of interactive Web applications that draw upon content retrieved from external data sources to create entirely new and innovative services. They are a hallmark of the second generation of Web applications informally known as Web 2.0. This introductory article explores what it means to be a mashup, the different classes of popular mashups constructed today, and the enabling technologies that mashup developers leverage to create their applications. Additionally, you'll see many of the emerging technical and social challenges that mashup developers face."