An Overview of XML

XML is an acronym that stands for eXtensible Markup Language and represents a more general way of defining text-based documents. XML descends from SGML (Standard Generalized Markup Language) and is specifically targeted for use with the Web. The greatest difference between HTML and XML is the flexibility of the allowable tags. In HTML any tag you can use must be taken from a fixed subset. An XML-based document, instead, can define its own tags, as well as include a set of tags defined by a third-party.

This kind of flexibility relies on a parser that reads a document type definition (DTD) for a specific XML document if one is available. By defining a new DTD you establish a set of rules and a set of tags creating de facto a new markup language. This may become very useful for those applications that need to deal with very complex data structures. A DTD is a text file that describes the syntax of the tags you're using in that class of documents.

However, you don't need to always define a new DTD. The IE4 XML object model allows you to take in any XML document and climb it as if it were a tree. In this way, you can examine all the tags and their nesting. This is what

scrobj.dll
does when registering the Server Scriptlet, or invoking one of its methods or properties. More information on XML may be found in the Internet Client SDK available at:

http://www.microsoft.com/msdn/sdk/inetsdk

Alternatively, a FAQ on XML is available at

http://www.ucc.ie/xml/
.

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