XML and How it Will Change the Web

How XML will change the Web

Everyone wants to know how XML will change the Web. First of all, XML will not replace HTML. The two markup languages are designed for different purposes, and they will coexist on the Web for many years to come.

Now that I've laid to rest Web developers' biggest concern about XML, let's consider what impact XML will have on the Web. XML will establish a universal data format on the Web. Better business-to-business communication, better agents, and better searches will all be made possible by XML.

Enable universal data
If you look at the Web today, you'll find several universal technologies, including TCP/IP, HTML, and Java.

• TCP/IP is the universal connectivity protocol; everything from mainframes to laptops to cellular phones can connect to the Web using it.
• HTML is the universal rendering language. Although not all browsers support all functions, there is a core set of HTML tags that can be rendered on any browser.
• Finally, Java's promise of "write once, run anywhere" makes supporting the wide variety of devices on the Web much easier.

Because of these ubiquitous technologies, it's relatively straightforward to create a Web application that runs on any platform. XML completes the picture by enabling universal data. You can build an XML document that describes a data structure, and that structured data can be sent anywhere across the Web. XML will change the Web because of its power and flexibility as a data interchange format.

Enable business-to-business communication
One of the challenges in conducting e-business is communicating with other organizations, whether they are partners, suppliers, competitors, or even other groups within the same company. XML simplifies business-to-business communication because the only thing that any two organizations have to agree on is the XML tag set that will be used to represent data. Neither organization has to know how the other's back-end systems are organized. If my systems run OS/390 and your systems run Linux, that doesn't matter. If my databases are relational and yours are object-oriented, that doesn't matter. If my code was written in C++ and yours was written in Java, that doesn't matter. The only thing that's important is that we agree on a standard set of tags for data interchange.

Once we've agreed on a tag set, each of us can write the mapping code to transform XML documents into whatever format we need to work with our back-end systems. For example, an XML document that's received from a partner might be parsed, then converted into a transaction that drives some business process on my system. Even better, if another company joins our consortium, we don't have to write more code to interact with the systems of the new company. We simply require that company to follow the document rules we defined in our XML tag set.

Enable smart agents
When writing an agent, one of the challenges is to make sense of incoming data. A good agent interprets information intelligently, then responds to it accordingly. If the data sent to an agent is structured with XML, it's much easier for the agent to understand exactly what the data means and how it relates to other pieces of data it may already know. As we illustrated in our sample HTML document, writing code to interpret the data contained in HTML tags is difficult and error prone. With XML, the structure of the data is easily determined and manipulated.

Enable smart searches
A major problem with today's Web is that search engines can't process HTML intelligently. For example, if you're searching for someone named Chip, you might get pages for chocolate chip cookies, RAM chips, poker chips, and guys named Chip. On the other hand, if you were searching for documents that contained a tag with a value of "Chip," you would get much better results. Being able to limit searches to those XML documents that use a certain set of tags would allow you to weed out a massive amount of unrelated content.

As an aside, being able to limit search results to documents that use a particular tag set is one of the market forces that will drive the acceptance of XML. Say that a group of automobile dealers defines a tag set for used cars, and that several popular search engines promise great results because their search engines look only at XML documents using those tags. If you're an auto dealer, you can either join the market and support that tag set or be left out of the market completely. If your inventory is not described using the standard XML markup, would-be car buyers using an XML search engine will never find you.

The promise of XML

XML is poised to change the Web, enabling a whole new generation of e-business applications. Just as HTML and graphical browsers sparked an exponential growth in Web use, XML's enhancements to e-business will start another period of exponential growth. Let's get started!