Aside from that, it's hard to find an industry or interest that isn't taking advantage of the fast-growing standard for Web services and data exchange. In the six years since the main XML specification was first published, it's spawned hundreds of dialects, or schemas, benefiting everyone from butchers to bulldozer operators wishing to easily exchange information electronically.
While some industry observers worry proliferation has gone too far, potentially creating new instances of the interoperability problems that XML was meant to solve, proponents say the explosion of schemas is a testament to the format's success.
Tim Bray, co-inventor of the main XML specification, said the proliferation of special-interest XML dialects validates what he and his colleagues set out to achieve.
"The idea from the start was to make it as easy as possible for people to come up with their own special languages for their specific problems," Bray said. "In the big picture, I think XML is more successful than any of us who designed ever thought it would be."
XML everywhere
Extensible Markup Language offshoots such as Web logging foundation Really Simple Syndication and new Microsoft Office formats get all the attention, but XML is transforming the way people exchange information in countless areas.
Some examples you might have missed:
• LandXML is a format for arranging data on terrain. It's most commonly used to feed data from engineering applications that design roads, construction sites and other projects directly into navigation systems. Bulldozers and other construction vehicles use the systems to eliminate most of the need to have surveyors on site during construction.
• Karst Markup Language is one of several efforts to develop an XML schema optimised for sharing data from cave surveys and maps.
• Recipe Markup Language uses XML to create a standardised format for organising and presenting cooking directions.
• MusicXML is one of several efforts to create an XML format for expressing music and notations. Among the potential benefits, scores could be fed directly into MIDI systems for playback.
• Theological Markup Language is meant to standardise scriptural citations and other references to theological documents.
• Mind Reading Markup Language is an apparently farcical and now abandoned project to mess with your head.
Source: CNET News.com research
Also, XML data exchange is a must for companies wishing to join the growing movement toward building new business software using a more flexible model called a "services-oriented architecture." Proponents say SOAs can make software easier to reconfigure as needs change and that they're cheaper to maintain in the long run.
As a vehicle for describing complex sets of data in a globally comprehensible way that works smoothly across the Internet, however, XML is already there. Just ask your local chicken farmer, who is, or soon will be, benefiting from Meat and Poultry XML (mpXML), an offshoot of the Global Standards Management Process that is designed to meet the special needs of producers, retailers and distributors of flesh food.
Turns out meat is a classic example of an industry with agreed-on data sets (Prime or Choice? Wing or drumstick? Fresh or frozen?) where speedy electronic transmission of data can be a major asset, said Blake Ashby, executive vice president of mpXML.org.
"Anything our people can do to move that product through the supply chain faster pays off for them in less shrinkage" and spoilage, he said. "Without a system, the managers of these (grocery store) meat departments have to spend time walking the aisle and seeing what they have too much of and when it expires."
Relatively speedy industry agreement on XML has helped producers and sellers boost business and prepare for new challenges, Ashby said. "The need for a global standard has really increased, especially now that Congress is pushing for country-of-origin labelling," he said.
The benefits of XML were similarly obvious for the newspapers and other media outlets that need to deal with voluminous and often inconsistently formatted statistics reported on sports pages, said Alan Karben, chairman of the SportsML Working Group, a branch of the International Press Telecommunications Council that oversees Sports Markup Language.
"Because people's appetites for esoteric sports statistics are so insatiable, the data reports that get exchanged and formatted for display are often incredibly intricate," Karben wrote in an e-mail exchange. "For our industry, the benefits of XML are clear: consistent input no matter what the provider, what the sport, what the native language."
XML has succeeded, co-creator Bray said, because it has solved several of the more vexing challenges for electronic data exchange, including growing need to deal with diverse languages and character sets.
"One of the big problems is internationalisation," Bray said. "One of the reasons XML took off is because it solved a lot of those issues with Unicode, which was fairly new at that point."
How much is too much?
While XML makes it easy to create special-purpose dialects, the privilege shouldn't be abused, Bray warned. Competing schemas handling similar tasks create the potential for confusion and broken connections. Consider musical notation, where there are at least a half-dozen projects to apply XML to standardising music scores. Similarly, the seemingly arcane field of cave exploration has inspired at least three attempts at XML data standards.
