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Java* has become a popular programming solution for delivering network applications, providing an object-oriented paradigm for client-server applications. Using Java, Web pages can be programmed to add animation and special effects to objects with simple scripts. The benefits of Java in developing channels is in the use of components written as Java applets. (Applets handle special effects, animation, ad banners, text formatting, 3D effects, databases and so on.) Since Java is not platform-dependent, it is considered a good programming environment for delivering client/server applications. Its support in both Netscape 4.0 and Microsoft Internet Explorer*-- makes it a good choice for developers, as well. Java applets within Web pages to enhance their look and feel.

Another benefit to Java applets is their use as Webtops or active desktop components. Simple applets can be created to provide features such as headlines, notifications, banners and tickers. In game applications (see Chapter 5) a Java-based applet was designed to deliver advertising banners from multiple channels.

The applet is not very CPU intensive, but when integrated with rich multimedia such as Indeo Video 5.0, the applet tends to run into performance problems on low-end machines. The integration of Java applets and rich multimedia content requires high performance systems in many cases.

Much like Java applets, ActiveX* controls are intended to be reusable building blocks for applications. A variety of ActiveX components provide functionality similar to Java applets. Several ActiveX controls were used in the creation of several of the channel applications. An URL Link Resolver was used in the theater application to retrieve stored AVI clips off the CD-ROM. Microsoft Wallet’s* Address and CreditCard ActiveX controls were used to capture address and credit card information. The developer can choose from a wide variety of both ActiveX controls and Java applets building blocks to develop channels.

Dynamic HTML and the ability of both Netscape’s Netcaster* and Microsoft’s Internet Explorer* to handle HTML elements as objects makes livening up a Web page much easier. Scripts can be written to make elements animate across the screen. Special effects can be used in text and graphics to add professional-looking graphics and typesetting to a Web page. Microsoft’s Dynamic HTML features "scriplets", which allow for distribution of HTML and code as objects residing anywhere on the Internet.

Software agents are interactive personalities that can act as guides or companions for channel users. These agents can be added to provide an interactive, conversational interface that leverages the natural aspects of human social communication.

Microsoft* provides several agent application programming interfaces (APIs) that make agents accessible to programming languages that support ActiveX technologies. For more information regarding Microsoft’s agent, visit www.microsoft.com/workshop/prog/agent.

VRML 2.0 is an emerging standard for providing 3D virtual reality worlds across the Internet. VRML consists of a text description of a 3D world. The text contains nodes that form the basis of VRML worlds. These nodes contain information about 3D objects, animations, lights, colors, sounds and video. Four basic primitives are put together to define a VRML world: box, cone, cylinder and sphere. These building blocks can be combined to form a 3D world that a user can navigate through and experience in real time. VRML combined with 3D sound can create a very interactive virtual world.

A lot of the 3D worlds on the Internet are used to generate a community in which users can gather and interact with each other. Included in these worlds are avatars that interact with individuals. Advertising avatars can be deployed to interact with users and act as virtual salesmen. Avatars with information about a variety of products can help promote electronic sales on the Web.

VRML worlds require large multimedia assets, such as textures, that need to be downloaded. Depending on the 3D world, they are sometimes too large to download over a 28.8-Kbps modem. To get around this problem, the textures and entire VRML world could be distributed on CD. For our game channel, the 3D VRML world is distributed on the CD to provide real-time performance when accessing the world.

Active Server Pages (ASPs) allow for dynamic content creation within a Web site-based on scripts written on the server side. This is in contrast to Java and Visual Basic scripts run scripts on the client side. ASPs are designed to provide a powerful scripting language for delivering dynamic Web pages to the user. The output of ASPs return standard HTML pages after running scripts on the server side. This flexibility is useful in delivering content based on user preferences or even asset resolution on the client’s PC. The Microsoft Merchant Server* is written entirely in ASPs and is easily customizable.

*Other brands and names are the property of their respective owners.

© 1997 Intel Corporation. All rights reserved.

* Legal Information © 1998 Intel Corporation