The State of the Art: Standards

When viewed from today's media-centric world, the old days of the World Wide Webway back in the early to mid-1990sare mere sepia-toned recollections. Today, with so many personal computers and portable devices having always-on access to the Web at home, work, and leisure, the world's users expect not only quick answers, but efficient and entertaining displays of data, akin to the rich experience offered by today's videogame-charged e-atmosphere.

Although coined by Macromedia in 2002, the term "Rich Internet Application" has come to mean a combination of software and content that, once delivered to a client computer (typically in a web browser), has a life of its own. Users interact with content and interface elements just as they do in standalone applications installed on their computers. But if the user creates or modifies information, the data is typically stored on the server, not the client computer. The next time the user accesses the applicationeven from a different browser on a different computerthe user expects the application to behave the same way, with previously preserved data ready for use.

A variety of technologies have allowed the creation of rich Internet applications for nearly 10 years. Java applets, available in popular browsers since 1997, didn't take the world by storm as predicted. In contrast, Macromedia's Flash technology has attracted a dedicated following. Even so, the universal browser support of the standards-based Hypertext Markup Language (HTML), ease of content creation in that medium, and the fact that content composed as HTML becomes easily searchable through web search engines have contributed to the overwhelming popularity of HTML as a fundamental content medium. Then, thanks to a few browser technology and standards developments over the years, even the once stodgy and static HTML content can become dynamicweb pages can "think and do" on their own, with little or no help from the server once they have been loaded in the browser.

The allure of the Webin theory anywayis that publishers and application developers can rely on well-known standards that facilitate the rendering of, and interaction with, data. Freed from details of painting dots on monitor screens, managing memory, and controlling internal data flows on dozens of operating systems, publishers and developers can focus on their content and server-side data handling. Browsers do all the operating-system-specific dirty work by interpreting Hypertext Markup Language (HTML) and other directives embedded in the content.

Although dynamic web pages are implemented under the umbrella of Dynamic HTML (DHTML), successful deployment requires knowledge of several technologies and standards that exist well outside the charter of the original HTML Working Group. In this chapter, I'll discuss the applicable standardization efforts, including some proprietary items that have become de facto standards. As disparate as this collection may appear at first, they all magically come together as a system to let creative designers implement engaging DHTML content.