Chapter 1 :
XML in Context
We are truly living in wonderful and privileged times. We can schedule airfare and book hotels from the convenience of our homes. Finding restaurants and mapping directions to a 3 P.M. meeting is as simple as opening a Web browser. Gone are the long waits in ser-vice lines and the 30-minute hold times with the inevitably rude customer service person-nel. We can order phone service, view real estate and apartments, shop and bid on flea market items, lodge customer-service complaints, and even file our tax returns without ever having to leave our homes or pick up the phone. We don’t even have to interact with a single human being. In fact, we can now live our entire lives without ever having to leave our homes. All these wondrous things would have seemed impossible a mere decade ago, and some of them are only now beginning to be realized.
Of course, none of this would be possible without data—the lifeblood of information flow. Everywhere we look, data is present. It’s in the phone bill we receive in the mail, the bar code on our soft drink beverage, the e-mail we exchange, the tax forms we pre-pare, and the millions of financial and banking transactions that occur on a daily basis without our knowledge. In the context of our discussion, data is any and all information that can be represented in a computer. Data is so intertwined with computing that to say one can exist without the other is akin to saying that humans can exist without organs.
What’s more, the Extensible Markup Language (XML) is powering this data revolution. This book, XML Unleashed!, is designed to get you well on your way toward developing XML applications and systems that enable your most important business processes as well as your simplest visions for data representation and exchange. Written for those already familiar with many of the concepts of XML but still not sure how to make best use of the technologies, this book aims to help you become a more advanced user of XML. Although this chapter covers the way that XML came to be, the “meat” of this book starts very soon in Chapter 2, “The Fundamentals of XML.”
Written for intermediate-to-advanced XML developers, this book covers all the necessary topics, from the basics of Document Type Definitions (DTDs) to the more advanced top-ics in XML database integration and the semantic Web. The foundations of XML as well as specific development methodologies and applications are contained within. By reading this book, you can unleash the XML developer within.
In this chapter you will learn:
What XML is
Why XML is important
Why the timing of XML is right
What other technologies, such as EDI, SGML, and HTML, have brought to the table
• Why those technologies are insufficient to solve our problems 1
Where XML is heading