Some of the files you find here may require specific software to be viewed. Viewers allow you to read documents and images created with a particular word-processor or graphics package even if you don't have the software concerned. Here are a few of the ones you are most likely to need here:

  RealPlayer - for audio and videos.

  Quick Time Player

  Shockwave - for some videos.

  Adobe Acrobat Reader - for PDF files.