ARCHIVED: For web browsers, what are helper applications, and where can I find them?

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Helper applications are stand-alone programs that a web browser uses to present files it cannot present on its own. When a web browser (e.g., Internet Explorer or Netscape) encounters a format or protocol it cannot display or access itself, it looks for another program that can. The browser downloads the file, then searches your computer for the helper application that can open the file.

A browser can determine which type of file it is downloading by the file's MIME type, which is typically indicated by the three- or four-letter extension at the end of the filename. Browsers like Netscape and Internet Explorer will recognize just about any file you wish to download.

To use a helper application, all you need to do is install it. Web browsers usually have a certain number of helper applications set up by default, serving the most common web browsing needs. In addition, you can set up as many helper applications as you want. For more information about helper applications, see Netscape's helper application page at:

  http://wp.netscape.com/assist/helper_apps/