| The eXtensible Markup Language (XML) has become a widely used technology for storing and exchanging information between dissimilar systems. Like HTML, XML in its basic form consists of tags and content. Unlike HTML, however, there is no standard library of tags for developers to use. Instead, developers create their own tags that are appropriate for the task at hand. For example, if I were to create an XML document to describe this book, it might look something like this: [View full width] <book> <title> ColdFusion MX: From Static to Dynamic in 10 Steps </title> <author> Barry Moore </author> <abstract> A kinder, gentler introduction to the world of dynamic web publishing using  ColdFusion MX. </abstract> </book>
You can see that the tags describe what they surround. For example, you know that Barry Moore is an author. If the name Barry Moore were surrounded by standard HTML <P> tags or <H2> tags, it would tell you nothing about Barry Moore or who he is. In effect, XML documents become a sort of self-describing data sheet, which makes them a very powerful and flexible way to exchange data. Our browser, however, would have no way of knowing how to display <author> tag content. To actually use XML documents in any meaningful way, there usually needs to be some kind of processing or transformation that happens to the document. This complex processing has typically been what has kept developers from using XML more extensively. ColdFusion MX now comes with a number of built-in tags and functions that make it easy to work with XML. | 
