What is XML?
The Extensible Markup Language (XML) might sound like an intimidating coding language for a small business owner, let alone a technology manager, to master. The odds are, however, that if your company has a website, XML is already part of the technology you are using to do business.
XML is a simple, flexible text format that was originally designed in the mid-1990s by an 11-member working group under the guise of the World Wide Web Consortium (WC3), an international standards body, to meet the challenges of large-scale electronic publishing. More recently, XML has become widely used to facilitate sharing data between different information systems over the Internet.
“If you need XML you’ll know it, because it is already part of the technology you’re using,” says Greg Bowling, senior analyst at Jupiter Research. XML, he explains, is part of the underlying communication online. “When you’re communicating between two websites, the XML tags the key attributes. This allows companies, and site operators to set data definitions for the trading of information.”
Essentially XML makes sure that all the various companies are on the same page when sharing information over the Internet. In this way, XML is akin to a digital glossary. But, without it, data couldn’t be easily shared between businesses without having to reformat that information at each step of the process.
An example of XML
As the Internet and the World Wide Web became more popular as a means of doing business, XML was created as an expandable version of the Standard Generalized Markup Language (SGML), which itself dated back to the 1960s. Markup languages are, in general, mechanisms for representing data in text-based files, and XML’s simple, flexible syntax has made it the preferred way for representing data in the e-commerce era.
In XML, data is broken up into elements that are identified by angle brackets in the following manner:
The two text elements within angle brackets identify the type of element being represented, while the text between them is the value. Elements like this can be nested, and can also receive other information called attributes to further classify the data, as in this example:
Here, the element “computer” has an attribute called “hard_drive” with a value of “100GB.” It also contains a hierarchy of other information about the manufacturer, including the model number.
XML and your business
Essentially businesses that need to share basic information with a common nomenclature are the ones that will mostly likely need to use XML. As a result of the increasing need for businesses to do business with other companies and customers over the Internet, XML is used in nearly every industry. It's an integral aspect of what makes the Internet work.
Hypertext Markup Language (HTML), the code that Web pages are written in, is also a subset of SGML, just like XML. However, modern Web development focuses mostly on XHTML, an XML-compliant subset of HTML that was created partly due to the difficulty in verifying the validity of HTML documents. Using XHTML enables webpages to be validated like XML documents above, meaning you can run tests against and ensure a webpage is valid before it ever goes live.
“XML was developed as a way to describe information that is shared in a specific industry,” explains Patrick J. Gannon, president and CEO of the Organization for the Advancement of Structured Information Standards (OASIS), a nonprofit, global consortium that encourages the development and adoption of e-business standards. One example that Gannon stresses is a computer industry supply chain. “Information can be shared among manufacturers, suppliers and vendors using XML," he says, "but it is really transparent to the business.”
However, with XML standardization is important with this sharing of information. This is where organizations such as OASIS fit in. “Anyone can take XML and make their own extensions, but doing so without standards will lead to chaos,” Gannon says.
With the proper standardization within industries, XML can enable a company’s servers to directly interact with other companies over the Internet and use XML messaging to define, validate and exchange data.