STP Viewer - Free STP Viewer - free software that lets you view 3D STEP files (.stp, .step file format).
de·caff Viewer - The de·caff Viewer version 3.
A360 VIEWER - Free online CAD Viewer
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.
Glovius - Extensible & customizable 3D viewer, for consumption of product design data.
Free DWG Viewer - Free Viewer for DWG, DXF, DWF View AutoCAD DWG/DWF/DXF files View & measure DWG, DXF, DWF