LiteCAD - Create, edit, view, and print 2D CAD drawings using the file formats: dxf, dwg, shp ;Download-Size...
STP Viewer - Free STP Viewer - free software that lets you view 3D STEP files (.stp, .step file format).
Morpholio Trace - Morpholio Trace is widely called to be the dream software of the designers and architect.
A360 VIEWER - Free online CAD Viewer
Free DWG Viewer - Free Viewer for DWG, DXF, DWF View AutoCAD DWG/DWF/DXF files View & measure DWG, DXF, DWF
ODA Viewer - ODA Viewer is a web-based software solution that allows you to view the files based on ODA format and you can easily zoom the file for detail visualization.