In this age of information technology, humans are collecting a prodigious amount of data about
things and activities, both of which are wont to be annotated with locations. All of these diverse
data sets that contain location data are just screaming to be presented graphically using maps.
One of the big catalysts for the advent of mashups was Google’s introduction of its Google Maps
API. This opened the floodgates, allowing Web developers (plus hobbyists, tinkerers, and others)
to mash all sorts of data (everything from nuclear disasters to Boston’s CowParade cows) onto
maps. Not to be left out, APIs from Microsoft (Virtual Earth), Yahoo (Yahoo Maps), and AOL
(MapQuest) shortly followed.
Video and photo mashups
The emergence of photo hosting and social networking sites like Flickr with APIs that expose photo
sharing has led to a variety of interesting mashups. Because these content providers have metadata
associated with the images they host (such as who took the picture, what it is a picture of, where
and when it was taken, and more), mashup designers can mash photos with other information that
can be associated with the metadata. For example, a mashup might analyze song or poetry lyrics
and create a mosaic or collage of relevant photos, or display social networking graphs based upon
common photo metadata (subject, timestamp, and other metadata.). Yet another example might
take as input a Web site (such as a news site like CNN) and render the text in photos by matching
tagged photos to words from the news.
Search and Shopping mashups
Search and shopping mashups have existed long before the term mashup was coined. Before the
days of Web APIs, comparative shopping tools such as BizRate, PriceGrabber, MySimon, and Google’s
Froogle used combinations of business-to-business (b2b) technologies or screen-scraping to
aggregate comparative price data. To facilitate mashups and other interesting Web applications,
consumer marketplaces such as eBay and Amazon have released APIs for programmatically accessing
News sources (such as the New York Times, the BBC, or Reuters) have used syndication technologies
like RSS and Atom (described in the next section) since 2002 to disseminate news feeds related to
various topics. Syndication feed mashups can aggregate a user’s feeds and present them over the
Web, creating a personalized newspaper that caters to the reader’s particular interests. An example
is Diggdot.us, which combines feeds from the techie-oriented news sources Digg.com, Slashdot.org,
This section gives an overview of the technologies that are facilitating the development of mashups.
For further information about any of these technologies, consult Resources at the end of this
A mashup application is architecturally comprised of three different participants that are logically
and physically disjoint (they are likely separated by both network and organizational boundaries):
API/content providers, the mashup site, and the client’s Web browser.