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Viewers

Although the WWW can be used to access information objects of practically any type — text, image, sound, and video — most of the current crop of browsers are limited to displaying text with inline graphic images. To support the viewing or sound of other object types, external viewers are used. These are separate applications that can be invoked automatically by the browser based on the file extension of the file in which the object is contained.

Each browser application has its own method of configuring the viewers to be used for a given object type. Some rely on manual editing of Windows.INI files, for example, and others provide pop-up menu support.

Several viewers are available as freeware or shareware applications along with browser distributions. Popular viewers for Windows include Lview for JPEG images and WHAM for sound files. For Macintosh, popular viewers include JPEGView for Joint Photographic Experts Group images, SoundMachine for audio, and Sparkle for MPEG video.


Exhibit 5.  Gateway Transparency.

Gateways

In the same way viewers are used to enhance the usefulness of browsers, gateways are used to enhance the usefulness and extend the reach of servers. From the perspective of the user, gateways are transparent, as shown in Exhibit 5.

Several special-purpose gateways provide features including the ability to perform keyword searches, send mail, or access relational databases. Another popular type of gateway tailors responses depending on where the user clicked within a graphical image. Most servers today support an interface known as the CGI, which allows the development of gateways written in a variety of computer languages capable of supporting practically any requirement.

HTML Tools

To facilitate the deployment of Web-based information, several HTML conversion and authoring tools have been developed. Most HTML tools provide conversion capability for the more popular word processors, including Word and WordPerfect, and for a wide range of document formats, including postscript, Rich Text Format, FileMaker, troff, LaTeX, BibTeX, Interleaf, and QuarkXPress.

HOW SECURE IS THE WEB?

World Wide Web security is essentially no different from security for other networked applications. Data privacy, data integrity, and protection from attack are key concerns for business users of the Web. In many ways the solutions are the same as they are for other networked applications. For example, because of the ability to download files using a Web browser instead of an FTP client, procedures for protecting against viruses are essentially the same.

In the early stages of Web development, the Web was used primarily for the purpose of publishing information to as wide an audience as possible. Consequently, data privacy was not a concern initially. More recently, however, people have begun using the Web for distributing information of a more private nature and for buying and selling goods and services across the Internet. These requirements are driving the need for more stringent and specialized security measures.

Security standards for the Web are still being developed. Two primary contenders have been proposed to solve the general problem of securing data flowing between browsers and servers. One approach, known as the SSL, provides for a secure connection at the TCP layer. An alternative to SSL, known as S-HTTP, provides encryption of selected fields within the HTTP protocol packets.

EMBEDDING WEB TECHNOLOGY IN OTHER PRODUCTS

The WWW has become so popular because it is based on relatively simple protocols that offer sophisticated service — access to a wealth of information spanning the globe. Growth of the Web has continued unabated since its inception, and Web traffic (specifically HTTP packets) has begun to exceed E-mail traffic on the Internet’s backbone network, NSFNet.

In addition to mere growth of the numbers, technological capabilities are expected to continue to be enhanced. A second-generation HTTP is under development and is expected to be published in late 1996. HTML will most likely continue to be enhanced, and Web authoring tools, viewers, and gateways will continue to become more sophisticated.

Despite these continuing trends, however, it appears likely that the most important change with respect to the Web will be outside the realm of the Web and Web products. Specifically, Web capabilities are beginning to emerge as a set of embedded features within other products such as operating systems and word processors. Once this happens on a large scale, users will be that much closer to having access to a world of information at their fingertips.


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