AutoCAD WS (formerly "Project Butterfly") is a free, cloud version of a CAD editor that supports the DWG and DXF file formats. This CAD tool runs on virtually any device - so you can create and edit your CAD drawings anywhere - online from an internet browser (on any desktop computer, laptop or netbook), and with WS Mobile even from a mobile device like a Smartphone PDA, Apple iPhone,Go to the original post...