Multimedia on the Web
Everyone wants a web site that is as active and dynamic as television or a CD-ROM program that plays in your computer. Buttons should visually and audibly click; visitors should be greeted with music; dazzling images should appear and disappear on the screen.
Unfortunately, the web is not as dynamic as television or a CD-ROM-at least not yet. Eventually, it will get there, but introducing multimedia poses real challenges and trade-offs. For those with limited budgets-or those trying to keep their sites accessible to the general population-important choices must be made.
Currently, there are four major ways of adding animation to a web page: server push, Shockwave, Java and GIF animation. Below is a discussion of the challenges of delivering animation to web visitors and the pros and cons of the major choices.
Browsers: Window to the Web
Those who wish to use the World Wide Web must have a "browser." Browser software lets people visit web sites and see the words and images at those sites.
Originally, the most popular browser software was called Mosaic. Developed at the National Center for Supercomputing Applications at the University of Illinois, Urbana-Champaign, Mosaic swept the web into popularity in late 1994. Soon after, many top developers of Mosaic were swept up and become the core of a new company called Netscape Communications Corporation. By mid-1995, Netscape's web browser, Navigator, grabbed an estimated 75% of the browser market.
Netscape's Navigator (commonly called simply Netscape) became so popular because it moved away from the limits of the standard HTML language used to created web pages and provided web authors with new ways to design pages. Before Netscape, web pages always came in gray, and centered text was nearly-impossible. By mid-1995, the web moved rapidly to adopt the special Netscape HTML "tags," as they are called.
The only downside to Netscape's popularity was that not everyone used it-and many other designers decided to pretend only the Netscape browser existed. Unfortunately, that meant despite Netscape's huge popularity, a significant number of people were left with garbled or unattractive web pages when viewed with other browsers.
Netscape's next big enhancement was the introduction of "plug-ins," originally known as "helper applications." A plug-in is a program separate from the web browser that lets viewers see a movie, hear audio and similar features. Visit any movie site, and you'll find movies available for download. However, without a plug-in, there is no way to see the movie.
By early 1996, 25 or more plug-ins were available for Netscape, offering a variety of means to significantly enhance web pages. Plug-ins are not a complete panacea, however, as discussed below.
One last significant point about Netscape was the introduction of Microsoft's Internet Explorer. The program offers many features similar to Netscape, plus a number of features that Netscape actually lacks, such as the ability to play Microsoft Video for Windows animation files without the need for a plug-in. Explorer is poised to prove a real challenge to Netscape, leaving developers in the position of choosing one or the other browser-or picking a middle ground to please the most people while keeping production costs low.
Native vs. Plug-Ins
Anything that a browser can display without the help of another program is what I consider "native." In Netscape, "au" format sound files, Real Audio sound files and Java programs are some of the native multimedia features. Microsoft Internet Explorer supports all of the above native Netscape features except Java (they've announced support is coming), plus Explorer can also play Video for Windows and "wav" format sound files, which are popular on Windows computers-the world's leading platform.
I believe in supporting native features over plug-in features-not exclusively, but certainly in budget decisions where choices must be made. Anyone using a browser can see native multimedia without problems. On the other hand, to see a plug-in multimedia feature, a browser user must have the appropriate plug-in software. This can involve downloading 1-to-2 megabyte files-a process that can take 15 minutes or longer for a modem user. After that, the plug-in must be installed.
Clearly, using plug-ins involves work on the part of the user-and I believe that the majority of users will not take the time. When plug-ins are shipped as part of a final product-involving no work for users to install (installation will happen invisibly to them), then plug-ins will require more support on the part of web developers.
Popular Multimedia Methods on the Web
Server Push: A process in which a single image is loaded onto the page, then the web server quickly "pushes" another image or multiple images into the same location. This is an ideal way to make small images change once or twice, but it is too slow and cumbersome to produce quality animation for those using modem lines.
Shockwave: Macromedia Director is a leading multimedia production program. Those creating CD-ROMs love the program, and a new add-on called Shockwave let animated images created in Director play in web pages.
There are two drawbacks to Shockwave. One, file sizes can get big, leading to long download times for modem users. This problem is rectified by simply using Shockwave wisely. The second, more serious, problem is that Shockwave is not "native" to Netscape 2.0. This means that those able to view Shockwave animations will always be less than the total percentage of Netscape users.
Java: A programming language developed by Sun, a leading producer of computer workstations and network equipment. Using Java, animations, interactive games and much more can appear within a web page. Unlike Shockwave, Java is completely programmable and has been licensed to many major browser companies-ensuring widespread support. Java's downside is that it can look slightly less polished than Shockwave. Java's big plus is that it is native to Netscape 2.0. That means everyone using Netscape can see Java applications without having to download a plug-in.
GIF Animation: This is an exciting technology that has been possible with GIF images for a long time but has come into its own now that Netscape 2.0 supports it. In a GIF animation, an ordinary image loads, then changes to an alternate image or images. This rapid display of image produces animation. GIF images are native to Netscape 2.0, making them an ideal way to deliver simple animations.