The PDF and movie files (Flash Viewlets) require reader software to view them. Adobe's Acrobat Reader and FlashPlayer software are probably already installed on your computer. To download the latest version of Acrobat Reader, visit the following page: http://www.acrobat.com.
To download the latest version of a Flash plug-in for your browser, visit http://www.flash.com and choose Get Flash Player from the Downloads tab.