Autodesk DWG TrueView - Get a free DWG viewer to view, open, edit, and convert .dwg files, the native file format for AutoCAD files. DWG Trueview includes DWG TrueConvert.
ArCADia-Architecture - ArCADia-Architecture is a revolutionary component for the instant creation of architectural documentation and object drawing.
Autodesk Design Review - Design Review lets you view, mark up, print, and track changes to 2D and 3D files.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
ZWCAD Viewer - Cross-Platform .DWG | .DXF | .DWT R12-2013 Viewer
Vectorworks - Vectorworks 2D / 3D CAD and BIM software for Mac or Windows provides one flexible solution for your entire design process. Sketch, model, and present with the ultimate software from start to finish.