Why move to XML?

Companies that adopt XML as their primary document format, as opposed to an HTML or word processor environment, should realize a large drop in their document processing costs and gain greater control over the creation, delivery and appearance of their documents. They also inherit a large set of tools that provide document management and processing support which are not available for HTML or word processor formats. Adoption of XML is generally an adoption of SGML, therefore you gain SGML strengths with the addition advantage that XML is a native Web format.

The best of both worlds
The world of SGML may seem complex and confusing, and HTML may seem familiar, but limiting. XML offers the best of both paradigms, establishing a document format that satisfies the needs of Web and content developers. XML is an investment in efficient content authoring, management and distribution. It is also a well-established set of SGML processes, and software and cost reduction in all areas of document production. While SGML is a very powerful language, it is just not practical for creating simple documents.

One size fits all users
XML documents can be manipulated to suit the needs of users. It is quite easy to apply a set of different style sheets to an XML document to achieve various styling or to manipulate content. For example, a writer may want to offer only the exercises contained in a document or only the theoretical components. Provided that a document is appropriately described, the writer can produce any view of document content that they wish. This feature allows various operations to produce vastly different views of the same content for different purposes. When possible, content re-use saves companies money and makes authors more efficient. XML supports and promotes these sorts of processes by being flexible and modular.

The name says it all. eXtensible
XML does not have a fixed number of tags or elements, as HTML does, but is extensible, as is SGML, allowing the document designer to define meaningful tags. XML represents a response to the inadequacy of both languages to meet typical information publishing needs in an era that includes global information networks, PDAs and conventional paper publishing. XML is designed as a slim SGML, better suited for software development, distribution on information networks, and for use on non-conventional computing systems. The virtue of XML will become clearer as the Internet expands and as information devices such as palm-held computers and cellular phones become increasingly popular.

The proof is in the output
To illustrate the benefits of separating structure from display, we can look at a common scenario that may occur in large and small offices on a regular basis. A document is created that will be needed in several output formats. This document will be needed in the following output formats:

Using traditional methods, a separate document would need to be created for each document type. By separating structure from format, only one source document is needed. This is the true impact of structured documents. Learning to separate structure from format is critical to making good use of the power of XML.

About the author
This article is an excerpt from the Professional XML Authoring course by Richard Landers © 2000 Online-learning.com