Keeping in step with the mission and goals of the W3C, HTML continues to be an evolving technology. Indeed, since the early days of the Web, HTML has seen some major changes in both its infrastructure and its implementation. Given the explosive growth of the Web in general and the tremendous (did someone say infinite?) range of applications that are being Web enabled, HTML has needed to keep pace with these changes to deliver on its goal to be a primary vehicle for the successful implementation of all of the Web’s promises.

Along the way, the W3C has presented various recommendations and related initiatives and work on HTML and HTML-related standards. From early tag standards to the now recent pairing and collaboration with HXTML, there is much you should be aware of in terms of how HTML has developed and how that development has been spearheaded by the W3C in many cases.

The history of HTML has gone through four basic iterations over the past several years. They are

• HTML 2.0. The early standards for HTML contained many of the core features still seen in today’s version of the language.
• HTML 3.2. The first W3C recommendation for HTML, this version added popular features such as support for superscript, subscript, tables, and so on. It also provided backward compatibility for HTML 2.0.
• HTML 4.0. This was an early gold standard for HTML, and it is the version to which most early HTML programmers took hold. However, HTML 4.01 has since superseded HTML 4.0.

You can still read the W3C specifications for each of the HTML versions listed here on the W3C Web site. In addition to being historically interesting, you can see how different functionalities changed from one version to another and how such functionality was accounted for to ensure backward compatibility with earlier versions of HTML whenever possible. Backward compatibility is an important point, and certainly one to keep in mind as you develop your own Web sites and anticipate the omnipresent push toward future needs and developments.

As I noted earlier in this chapter, you don’t have to be involved with the W3C (or even visit its Web site on a regular basis) to produce strong Web sites. However, in the exploding, ever-changing arena that is the World Wide Web, regular visits to the W3C can keep you abreast of changes that are coming down the technology pike and present you with vendor-neutral overviews and technology specifications.

For the latest updates to W3C HTML activity, visit http://www.w3.org/MarkUp/Activity.

Why worry about the vendor-neutral stance of the w3c?
Back in the early days of the Web (1997-1998!), browser compatibility was a much greater issue than it is now. Specifically, if you were designing Web pages, you had to be very aware of how your site might look (and function) if it were viewed in Microsoft Internet Explorer versus Netscape Navigator, for example. Although some differences were minor, there were other major differences in how the browsers interpreted HTML and related scripts (such as JavaScript). In the worst-case scenarios (and there were many of them), critical site functionality wouldn’t… well… function if it were viewed in a different browser than the one for which the site was designed. To make things more complicated, vendors would disregard HTML standards (for example, those recommended by the W3C) and build additional HTML functionality into their browser applications. Although some of this functionality was impressive, it presented a serious roadblock to the W3C’s universal interoperability goal (and the larger philosophy of the Web in general).Thus the browser wars began, and they are still fought today.

Fortunately, the W3C continues to take a vendor-neutral stance. Although you might not be able to completely escape the long reach of some of the vendor-specific requirements of your development environment (in other words, if you are in a Microsoft environment, you tend to play by Microsoft’s rules), you can still go a long way toward making your life easier—and making your site accessible to the greatest number of potential visitors—by avoiding as much vendor-specific functionality as possible, and by sticking to the universal recommendations set forth by the W3C (not just their HTML recommendations, but recommendations for all Web-related technologies).

In each comparison, there are significant display problems either because of backward-compatibility issues in the site design (in other words, it wasn’t designed for older browsers) or due to vendor-specific functionality only accessible in a specific browser.

Current HTML activity on the W3C site is rich, varied, and again indicative of the Web’s ever-changing nature. Much of the recent activity surrounds XHTML (Extensible Hypertext Markup Language; more on this in a bit); however, you can also view recent updates to other critical issues such as accessibility guidelines for the visually impaired or otherwise physically challenged.

Caution
Another issue to be aware of is if you are using a Macintosh. For example, Microsoft’s Internet Explorer Web browser will behave very differently (in some cases) on a PC as compared to a Mac. Indeed, Web pages in general—and the functionality they contain—may both look and act differently when loaded on a Mac. Just another issue you need to be aware of if you are building Web pages that will need to be (or that you want to be) accessed on a wide variety of systems, using different types of Web browser applications.

Although writing your HTML to be as vendor-neutral as possible is a great idea, there are other accessibility issues you should consider as well. Certainly, one of the most important issues is designing your site so it is as accessible as possible to the visually impaired or otherwise physically challenged. The W3C has published some recommended guidelines for making your site accessible in this regard. You can view these guidelines—as well as general accessibility guidelines—at http://www.w3.org/WAI/Resources/#gl.

What else can you find about recent W3C activity regarding HTML? The following is a short overview of some of the projects the W3C is currently working on; you can learn more about these projects by visiting the W3C site.

• XML. Defined as the universal format for structured documents and data on the Web, XML moves beyond HTML in that it allows for more precise placement and manipulation of data on Web pages.
• CSS (Cascading Style Sheets). In the old days, if you wanted to change the visual layout of a page (fonts, margins, and so on), you had to perform a lot of tedious, line-by-line code changes. With style sheets, you can set these attributes universally for your Web pages, and then quickly change them if you need to. I will cover style sheets extensively in Chapters 9 and 10 as well as within the project chapters.
• DOM (Document Object Model). DOM is an evolving method for adding dynamic effects to Web pages that is independent of specific languages or computer platforms (thus furthering many of the goals discussed earlier, including accessibility, interoperability, and the "Cooler Web"). You will explore this topic in more detail in the project chapters of this article.
• Internationalization. The Web is a worldwide entity, and thus should not be structured to present data in only one language. HTML 4.0 and 4.0.1 allow for the transmission and manipulation of various language sets, furthering the accessibility and ease of use of Web content across the electronic language barriers that previously existed.
• Accessibility. People with visual or other disabilities should not be prevented from taking part in the rich, developing arena that is the Web. The W3C and many other organizations (including hardware and software manufacturers) are making a dedicated push to ensure that the Web is accessible by everyone.
• XForms. This evolving technology seeks to add a tremendous amount of new functionality to typical HTML forms. You can read more about XForm development on the W3C site.
• Representation of mathematics on the Web. Remember your high school or college calculus class and all the formulas and mathematical functions? It often was hard enough to write those neatly, let alone type them! (Ah, type… the old days are certainly behind us, aren’t they?) The W3C is working on an XML application called MathML that seeks to ease both the presentation and interpretation of mathematical expressions on the Web.