Chapter 11: Extensible Markup Language (XML)

Overview

The common myth is that Extensible markup language (XML) exploded onto the scene in the late 1990s as a semantic alternative to hypertext markup language (HTML).^[75] In this chapter we'll dismantle that myth and reconstruct an even more interesting reality.

The reality is that economic and technical forces have aligned for XML to be the common denominator of all our semantic initiatives, for at least the next decade, including most content management, application integration, service invocation, knowledge management, and rule expression. However, as we will discuss in this chapter, XML is not a semantic language; it provides a place to store semantics.

I'll describe in this chapter how this has come to be and how we can be so certain about the role of XML. I'm also going to delve into some aspects of XML and its many derivatives that will aid the transition to semantically based systems. We'll examine the essential nature of XML, as well as the many technologies that have evolved within the XML ecology.

^[75]There wasn't anything in the language of the original proposal (see http://www.w3.org/TR/PR-xml-971208) that indicated an intent for XML to be a semantic alternative to HTML, but the press soon caught on to the idea.