Markup Languages: Their Origins and Applications

by Bobby McFall

Most people familiar with the Internet
know the acronym HTML stands for Hypertext Markup Language. But what is it, where did it come from, and how is technology influencing markup languages and web design?

Markup languages first appeared in the 1960s with IBM’s creation of GML, Generalized Markup Language, to manage data within their organization. In 1986, IBM created SGML (Standard Generalized Markup Language). ISO, the International Standards Organization, adopted SGML as an international standard for document formatting. Though still used today, SGML, remains a challenge in transitioning to hypertext documents.

Therefore, in 1989 experts created Hypertext Markup Language. HTML, considered an easily learned and understood markup language even for non-computer users, can adapt its language to create electronic documents, particularly pages on the Internet .

By looking back only ten years into the history of web design, one can track no fewer than six generations of markup languages, each an improvement over its predecessor. With the exploding popularity of the Internet, it soon became apparent that HTML could not meet the increasing demands of web design and complexity.

DHTML, Dynamic Hypertext Markup Language, developed in the early 1990s, combined three technologies: HTML, CSS (Cascading Style Sheets), and scripting, such as Javascript. DHTML has its faults, however. It only works on 4.0 or greater browser versions and has some browser specific capabilities. Internet Explorer and Netscape each support different versions of DHTML. For this reason, the W3C (World Wide Web Consortium) has not approved DHTML for standardized use. Such approval depends on its widespread acceptance.

DHTML technology:

• adds interactivity such as mouse rollovers and multimedia to web pages

• allows the designer to control how the HTML displays page content

• positions elements precisely in the window, and changes that position after the  document has loaded

• hides and shows content as needed

Web authoring software such as Macromedia’s Dreamweaver and Adobe GoLive contain DHTML capability and feature cross-browser compatibility.

In 1996 the W3C determined that it needed a more structured, easily validated, and extensible language to meet the requirements of web designers who found HTML insufficient for their purposes. The Web Developers Virtual Library describes XML (Extensible Markup Language) as "a human readable, machine understandable, general syntax applicable to a wide range of applications (data bases, e-commerce, Java, web development, searching). Custom tags enable the transmission, validation, and interpretation of data between applications and organization." Extensible means writers can specify their own tags and define their own attributes.

XML, an ISO compliant subset of SGML, may soon replace HTML. The W3C describes XML as a "universal format for structured documents and data on the Web." Due to its cross-browser capability in the global market, XML can succeed where DHTML does not stand a chance. XML:

• functions in a straightforward and usable manner over the Internet

• supports many applications

• works compatibly with SGML

• prepares designs quickly

• permits the author to develop content

derived from multiple sources

• gives a web client all the information needed to process data

• allows clients to sort, filter, and manipulate a data set locally

• allows each user to develop his or her own display parameters

• comprises its design in a formal and concise manner

• performs advanced search and navigation functions as well as complex formatting

The primary difference between XML and HTML lies in the organization of information. Writers can create their own tags for logical organization. Syntax in HTML confines the writer. XML also has the ability to single source. This means that a single file can create all information. In HTML, each page becomes a separate file rather than an all-inclusive file, as seen in the diagram.

Refinements stand to improve markup languages and take them to even higher limits. XHTML (Extensible Hypertext Markup Language) does just that. On December 19, 2000, the W3C released XHTML Basic as a recommendation. The W3C membership favors its adoption by the industry. People can view XHTML on their desktop computers,–– TVs, PDAs, pagers, and mobile phones can share its basic content. XHTML Basic reflects ten years of basic web experience, including advances in XML and accessibility.

In XHTML, elements of HTML and XML combine to make a single language. To ensure that web pages work the way you want them to in the next generation of browsers, you must follow W3C recommendations. XHTML standards help you do this.

While HTML, XML, and XHTML help to define web page content, a gap exists in web page design ability regarding standardization and acceptance by the W3C. A brand new style language called XSL may remedy this situation. In November 2000, it became one of the W3C Candidate Recommendations.

XSL, the style sheet language of XML, contains three parts:

• transforming XML documents

• defining XML parts and patterns

• formatting XML documents

While the World Wide Web continues to

evolve rapidly, web pages and the design elements used to create them also evolve at breakneck speeds. Technical communicators face the difficult but essential task of keeping pace with this changing technology. The websites listed below can help with this task.š

<Head>STC member Jones
Jones, Jane<br>
Phone: (321)555-1234<br>
123 Main Street <br>
Anytown, MN  55555 <br>


One HTML file

              <Street>123 Main Street
              <City>Anytown, MN 55555

One record within an XML file




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