DWF
From Just Solve the File Format Problem
DWF (Design Web Format) is one of the formats that can be saved by AutoCAD products from Autodesk. It is intended for publishing designs on the web, and there are browser plug-ins to view it.
There are two sub-formats, with .dwf and .dwfx extensions, the latter being composed of ZIP-compressed XML (and other data) in accordance with the Open Packaging Conventions, part of the Office Open XML standard related to the Microsoft Office file formats with "x" in their extensions.
