Understanding Plug-Ins, Java, and Other Programs in Pages

Up-to-date versions of Internet Explorer and Netscape Navigator come pre-equipped to play most (but not all) of the stuff you'll encounter online. So the most important step in preparing to play multimedia is making sure you have the latest version of your browser, so it supports native play of those file types.

When a browser has the built-in capability to play a particular kind of file, the browser is said to include native support for that file type. Anything the browser can do without help from another program is native; any capability in which the browser must call on another program (such as those in this chapter) is non-native .

As part of being extensible, Netscape Navigator and Internet Explorer can, in effect, be reprogrammed through the Web to acquire new capabilities. This happens chiefly through four types of program files:

• Plug-ins ” A plug-in is a program that implants itself in the browser to add a new capability. Usually, after you install a plug-in, that new capability appears to be a native, built-in part of the browser, as if it had always been there.

• Helper programs ” A helper program is a separate program that the browser opens automatically to deal with a particular type of file. For example, when you play a video file from within Internet Explorer in Windows, the browser typically opens up the Windows Media Player ”a separate program ”to show you the file.

  

  In practice, there's often not a whole lot of difference between a helper and a plug-in. In fact, the terms are often used interchangeably (and therefore incorrectly). The main difference is that a plug-in is generally more tightly integrated with the browser and usually can't play if the browser is closed. A true helper is self-contained ”it can be opened as needed by the browser, but can also be used when the browser is closed.

• Applets and scripts (Java, JavaScript) ” Both Big Two browsers can run program code delivered to them from servers ”in effect, little programs that run once and then go away. This code ”sometimes described as a script (when in JavaScript) or an applet (Java) ”is used increasingly to enable advanced multimedia and other cool, interactive stuff on Web pages.

• ActiveX controls ” An ActiveX control is a file of program code that teaches the browser how to do new things.

In general, you don't have to do anything special to take advantage of scripts, applets, or ActiveX; they're delivered to the browser automatically by Web sites. You just have to make sure that you use the most up-to-date version of Internet Explorer or Netscape Navigator, and you'll be all set.

Most other capabilities are delivered today through plug-ins (or plug-in “like helpers). Although plug-ins are occasionally delivered automatically, more often than not you must deliberately download and install a particular plug-in to enjoy whatever it does.

Finding Plug-Ins and Helpers

Usually when you come across a Web site or a file that requires a particular plug-in or other program, it's accompanied by a link for downloading the plug-in.

In fact, when you first enter the site, a message may appear on your screen informing you that a particular program is required and giving you a link for downloading it. On some sites requiring a specific program you do not have, your browser may show you a message telling you about the program. Often, that message includes a button you can click to get the program right away (see Figure 11.1).

Figure 11.1. Sometimes, when you enter a site that requires a particular plug-in or other program, you'll see a message that provides a handy way to go get the program you need.

Occasionally, though, the site doesn't help you get the right program, and you have to go hunting for it.

Fortunately, several excellent indexes are devoted to these programs. The logical first stop is Netscape, where a full directory of plug-ins is maintained , along with links to the latest, coolest ones to come out (see Figure 11.2). You can reach Netscape's Plug-Ins index at home.netscape.com/plugins/.

Figure 11.2. Netscape offers a terrific directory of plug-ins.

The simplest way to find out what file types your computer is already equipped to play is to simply try files as you find them. If, when attempting to play a particular file type, you see a message telling you that your computer or browser doesn't know what to do with that file, you need to find and install a player program for that file type. Before trying any files, however, make sure you have an up-to-date virus protection program installed and operating on your computer.

Installing and Using Plug-Ins and Helpers

Because these programs can come from any software publisher, no single method exists for installing them. Typically, though, you have to run some sort of installation program and then specify the directory in which your Web browser is installed.

When you come across a link to a plug-in or helper program a site requires, carefully read any instructions you see, click the link, and follow any prompts that appear.

After you install the program, you really needn't think about it any more. Any time you initiate an action in your browser that requires the plug-in or other program, it springs into action automatically. For example, if you've installed a plug-in that plays a particular kind of audio file, any time you click a link for that type of file, the plug-in kicks in to play it.

If you keep up with the latest release of your browser, you might not come across many occasions when you need to add anything to it, and you can deal with the rare situations one by one, as they arise.

Still, there are a few enhancements you're likely to need fairly soon. One is RealPlayer, described later in this chapter. Two more are the programs for playing two types of advanced media online: Flash (which enables you to see certain kinds of animation in Web pages) and Shockwave (which enables you to use certain advanced interactive features in some Web pages). Players for both Flash and Shockwave are available for download free from Macromedia (www.macromedia.com), although sites containing Flash and Shockwave content nearly always include an easy-to-find link for downloading the necessary programs.

Internet Explorer (versions 5 and higher) comes with a built-in Flash player, so you might not need a plug-in for Flash. However, the types of content these kinds of plug-ins play are constantly being updated, necessitating upgraded players.