This article weighs the pros and cons of XML for some applications (publishing), and explores why it is the best possible solution for many programming and publishing needs.

Everywhere you turn these days, someone is talking Extensible Markup Language (XML). Jump into a discussion about publishing—XML is touted as a means of exchanging information. Talk with someone about the new software tool she is creating—she describes setting up some of her actions in XML. Ask a webmaster what he’s been doing—he raves about the dynamic content he’s serving up to site visitors using XML from a database. In short, XML is a great solution to a wide variety of challenges, and it seems to be everywhere. But is it the cure for every data or content challenge? The simple answer is, no.

Everywhere you turn these days, someone is talking Extensible Markup Language (XML)

Not everyone needs XML to make things work. For some small organizations, publishing processes are straightforward enough that the costs of implementing an XML solution may not be worthwhile. But the only way to be sure is to perform a thorough examination of the business processes and review cycles that produce information products—most organizations and companies grossly underestimate the amount of information they could potentially reuse in publishing, and overestimate the costs of reusing that information with an XML-based solution. And they’re not aware of the breadth of available free tools that can get them well on the road to their XML destination.

What is XML?

XML is meta markup language that is used to create new markup languages. It’s most commonly used to create tag sets and processing instructions that describe structured content for presentation in text documents, but it can also be used to describe, manage, and deliver content of all types (text, images, voice, forms, multimedia files, and so on) and to transform transactional data between disparate database systems.

XML is meta markup language that is used to create new markup languages

Unlike Hypertext Markup Language (HTML), which is a display markup language with a predefined list of tag sets designed solely to control how information is presented in a web browser, XML presents content in an open, standards-based, media-neutral, operating system-agnostic, platform-independent format. XML is extensible because it allows organizations to define their own sets of tags, each with a meaningful (semantic) “name”. Semantic names (or tags) are more useful than generic HTML tags because they can describe content in real-world, user-friendly and context-specific ways. For instance, the XML tag <product name> is much more descriptive than the HTML tag <h2>.

In a traditional word processing environment, the formatting data is stored with the content it governs, and changes to the formatting involve changes to the content itself. XML’s strength comes in its ability to separate content from formatting data, thus allowing authors to create content without spending unnecessary time formatting that information. XML style sheets control the formatting of the content being created, and specify how it will be presented in each medium.

XML style sheets control the formatting of the content being created, and specify how it will be presented in each medium

XML content can therefore be automatically transformed (with the help of style sheets) from a single text source into a variety of information products (printed product brochures, web site content, wireless content, etc.) each with its own look and feel. And, XML content can be personalized and delivered dynamically on the fly, based on the specific requirements of the end user.

XML also differs from HTML in that it allows documentation to be processed by computer software programs, thus allowing organizations to reuse content from disparate data repositories, and recombine that data in ways – and in various media—not possible with HTML. XML supports single source content reuse, and allows organizations to make changes to a content element (like a product description) and have those changes reflected instantly and automatically in every information product that uses that information, regardless of the medium. This ability to reuse information and to make changes once and have them appear globally saves organizations considerable time and money revising, updating, and translating content.

XML content is also “validated” against document guidelines encoded in a Document Type Definition (DTD) and can enforce standards on the authors who develop content. This ability is particularly useful in validated or regulated environments (life sciences companies, legal firms, automobile and aerospace industries, the financial sector) in which completeness, consistent structure, and accuracy of information are all essential, if costly regulatory compliance and legal issues are to be avoided.

W3C Goals for XML

After the world wide web explosion, web users were inundated with miles of good and bad HTML, and the W3C sought a better solution for publishing, cataloguing, locating, retrieving and archiving data. The guidelines they set for this “something better than HTML” resulted in the development of XML. The “design goals” for XML, which set it aside from HTML, include the following (source: W3C).

1. XML shall be straightforwardly usable over the Internet.
2. XML shall support a wide variety of applications.
3. XML shall be compatible with SGML.
4. It shall be easy to write programs, which process XML documents.
5. The number of optional features in XML is to be kept to the absolute minimum, ideally zero.
6. XML documents should be human-legible and reasonably clear.
7. The XML design should be prepared quickly.
8. The design of XML shall be formal and concise.
9. XML documents shall be easy to create.
10. Terseness in XML markup is of minimal importance.

This article focuses primarily on the second W3C requirement for XML, that it plays well with a variety of tools that perform various tasks. And since the potential uses of XML are countless, and space is limited, we’ve restricted our scope to the use of XML in publishing.

XML Uses

In the publishing arena, XML is used by authoring and content management tools. Authors use the XML elements and attributes to produce documents. Content management tools use the XML elements and attributes as data that can be retrieved or marked for reuse.

Affordable publishing can sometimes be accomplished without the help of XML—XML would be overkill

Is this the answer to everything? Well, in the publishing world the answer is sometimes “no”, because affordable publishing can sometimes be accomplished without the help of XML—XML would be overkill. However, XML often is the best option for organizations that take the time to evaluate their content lifecycle and to examine how much it costs to create, maintain, translate, deliver, store, reuse, archive, and retire content. A recent study by ZapThink (“XML in the Content Lifecycle Foundation Report Creating, Managing, Publishing, Syndicating, and Protecting Content with XML”) found that the biggest—and most expensive—challenge for most organizations today is content reuse. The study found that “Producers of content in the enterprise spend over 60% of their time locating, formatting, and structuring content and just 40% of their time actually creating it.” (Source: ZapThink)

The sad fact is, most organizations don’t know how much their content creation and management efforts cost them, and so they assume that XML is not for them. The reality is that the only way to know whether XML is the right choice for your organization’s publishing needs is to seek the assistance of a content management expert who can perform an organizational needs analysis, a content lifecycle analysis, and an audit of your existing content. Additional services offered by content management consultants include customer needs analysis, tools recommendations and assistance calculating return on investment. Analysis often identifies obstacles to change (tools, processes, and people) that will need to be addressed before you adopt XML as a publishing solution. Once you know how much it costs, and what obstacles you’ll face, you can make an informed business decision about whether to move to XML publishing or not.