An Acrobat Reader can be downloaded by going to:  

  You can download Powerpoint Viewer here 
 

Flash, Shockwave
& Authorware viewer plug-ins are at:

You can get an evaluation version of Win Zip here:  

 
You can download Microsoft Internet Explorer here.

You can download Netscape Navigator at:  

Try ZD Net for a constantly updated list of the top twenty free downloads