to build applications around the DWF format, with the DWF Toolkit. Furthermore, DWF is based on other industry standards such as ZLIB, XML, and common image formats. DWF files (since version 6.0) are a ZIP-compressed container for the drawing files; despite the first few bytes of the file containing a DWF header, renaming a .dwf file to .zip will allow the component files inside to be viewed with archive compression software. Amongst various XML and binary files, is a PNG format thumbnail preview. DWF can be interfaced with .NET Libraries. Design Review Autodesk Design Review is a free viewing application that enables all members of the project team to easily view, measure, markup and print designs shared electronically. Built around the DWF file format, Design Review enables users to view and print complex 2D and 3D drawings, maps, and models published from Autodesk design applications or from the DWF Writer. Also, all Markups and Annotations created in Design Review can be imported to the original file when using Autodesk applications, such as AutoCAD, Inventor or Revit Architectural. This feature makes DWF the ideal format for design reviewing and collaboration processes. Although an Autodesk representative stated on the Official Autodesk user Forums in September 2013 that the application would be discontinued, an update to Autodesk Design Review was released in 2017. DWF Writer Autodesk DWF Writer software publishes the DWF format from CAD applications that do not offer built-in DWF publishing, such as Bentley MicroStation or Dassault's Solidworks software. Autodesk DWF Writer is a Windows printer driver that converts files to DWF format. The result is that the entire project team can standardize on a common file format to exchange and review designs and sheet sets, at no additional cost. Freewheel In 2007, Autodesk introduced an online translator for DWFs called Freewheel. Freewheel was a way to view a DWF file without downloading software. It was also a web service which offered developers a web-based interface for viewing, querying, and manipulating DWF files. Freewheel has been replaced by the web based viewing and editing web service Autodesk 360. Platforms Autodesk's DWF viewers (except for Freewheel) are all based on Microsoft Windows. The DWF Toolkit is available on Microsoft Windows, Linux, and Mac OS X. History The DWF format first appeared in 1995 as part of the unveiling of Autodesk's "WHIP!" Netscape Navigator plug-in. The format was originally referred to as the