Frequently Asked Questions

What is a mashup?

A web mashup is a web page or application that combines data from two or more external online sources. The external sources are typically other web sites and their data may be obtained by the mashup developer in various ways including, but not limited to: APIs, XML feeds, and screen-scraping.

Because mashups are often built using APIs (see below), this site gives you a variety of ways to view the relationship between a mashup and any supporting APIs used to create that application.

You can find out more about mashups at Wikipedia, this video from ZDNet's David Berlind and Mashup Camp.


What is an API?

An API, or Application Programming Interface, is a set of functions that one computer program makes available to other programs so they can talk to it directly. There are many types of APIs: operating system APIs, application APIs, toolkit APIs and now web site APIs.

The classic example is a computer operating system like Microsoft Windows with hundreds of APIs providing services from accessing your hard drive to drawing on the screen. These operating system APIs then are used by desktop applications like spreadsheets and word processors.

Today, APIs can be specified by web sites. Thus provides a set of 'retail APIs' that allow developers to create computer programs that make use of Amazon's sophisticated online retail infrastructure. Third-party software developers have used this to create specialized storefronts. APIs from eBay facilitate program-to-program auction management, Google's APIs provide search and mapping services, and so on.


What does the "Web as Platform" mean?

Historically, some types of software like desktop operating systems have been called 'platforms' because through their APIs they provide the foundation on which other programs are built. The phrase 'web as platform' refers to fact that as web sites start providing their own APIs, they too are becoming a platform on which other programs can be built. Sometimes this is also referred to as the Internet Operating System.


What is an "enterprise mashup"?

People generally use this phrase to describe the use of the APIs and techniques described on this site within a company's own internal applications. Often this is very similar to or extensions of existing Service Oriented Architectures (SOA) or Composite Applications and Dashboards. For more resources on this question see:


Are there events and conferences for this stuff?

Yes. The premier event is called Mashup Camp. The first event was held in February 2006 and Mashup Camp 2 was held in July 2006.


I like Google Maps mashups, where can I find more?

There are lots of sites with lists of Google Maps mashups. I'd first recommend Google Maps Mania, a terrific blog and resource run by Mike Pegg that's completely focused on what's new an interesting with Google Maps mashups.

In general, the best Google Maps sources you could try include:


I want to make a maps mashup but don't program, what can I do?

You have a variety of options including:


You list a lot of mashups on this site. Are these all the mashups there are?

No. This is a subset, or sample, of all mashups. The universe of web mashups is too large and dynamic to be cataloged in one place. And even that assumes that there's an agreed-upon single definition of what a mashup is. Which there isn't. That being said, this is probably the most diverse and structured collection available.


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APIs, mashups and code. Because the world's your programmable oyster.

John Musser
Founder, ProgrammableWeb

Adam DuVander
Executive Editor, ProgrammableWeb. Author, Map Scripting 101. Lover, APIs.