Question
How do I view a DWFX file without a viewer?
Answer
DWF and DWFX files can be viewed online using a service like Autodesk 360, in most cases, your web browser should be able to view 2D DWF files without any plugins.
The Desktop Application for viewing DWF/DWFX files is Design Review, it can be downloaded free from Autodesk here: http://usa.autodesk.com/design-review/download/?id=12423405&siteID=123112