A MashUp is a web application that combines data from multiple sources, creating a new hybrid web application with functionality unavailable in the original individual applications that sourced the data.
An emerging trend in web applications is to provide public APIs for accessing data that has traditionally been used only internally by those applications. The main purpose of providing access to traditionally private web application data is to encourage user-driven development. In other words, consumers are expected to take that public data and build custom applications for other consumers – thereby adding value to the original data sources. MashUps are web applications that take advantage of these publicly accessible data sources by correlating the data obtained from different sources and deriving some novel functionality. A simple and common example is correlating a data source that has location information (such as wireless hotspot locations) with cartographic...