The term may have originated in the music industry, where parts of two songs were combined to make something completely new, but in the computing world "mashups" are a tool that melds search engines. Software mashups are created when the tagging system from one site is combined with the Really Simple Syndication (RSS) feed of another. This new Web-based application is generating a lot of excitement as users figure out how to put the new information combinations to use, as technical whiz kids find more ways to combine existing information sites and entrepreneurs look for ways to develop commercial models.

Here’s how they work. Computer users combine existing web service sites like eBay, MSN, Amazon or Google on their own PCs to find information targeted to specific information needs. Mashups require at least two key elements - a search machine to hunt for data and a service that can display the results. Users access the key components and overlay different sets of data to permit more effective analysis. The resulting mashups are created only on the users’ PCs and don’t require users to create, or pay for, data or to pay costs associated with the web servers and equipment used by mega-companies like Google or Amazon.

Common Mashups
Some of the most common mashups involve combining data with maps. For example, ChicagoCrime (www.chicagocrime.org) took police crime data and plotted the incidents on street maps from Google Maps. Another - www.zillow.com combined real estate listings with satellite maps for prospective homebuyers. Other popular data feeds are weather and traffic information and listings of events or TV programming. In order for users to extract data, sites must have an applications programming interface (known as API). Large companies like Google, Amazon and eBay have been more than happy to let people access and reuse their data. To see what mashups are out there, visit a site like www.mashupfeed.com or www.programmableweb.com. They are proliferating quickly because they don’t require a great deal of technological savvy to turn an application idea into one. Mashups are not affected by national borders and can use local and international feeds.

The Future
Are mashups a passing fad or will they become an indispensable cross-referencing tool? The jury is still out, but many industry observers think that we may see a blossoming of opportunities. So far, mashups have been used mainly for information - for news updates - both national and local community reports. Advertising has yet to be a real player in the mix. When users pick up data, they don’t go to the site and see the commercial advertising. However, undoubtedly there are other possibilities to display data in ways that don’t exist now - ways that might make their creators wealthy. In the interim, today’s enthusiasts look forward to the availability of some practical applications - cell phones that can display maps and show individual commuters where traffic is congested, or for the shopaholic, mashup add-ons to on-line newspaper ads that show consumers where special sales or retail events will be.