To view a DWF file:
a. Each visitor to your site has to have Autodesk Design Review installed so they can view the DWF file natively.
b. You use Autodesk Freewheel so that visitors to your site get images files created by the Freewheel sever so that they do not need Autodesk Design Review.
c. You publish the file as a DWFx file so that Internet Explorer users can view it natively.