The Spinfire 3D CAD viewer allows users to view, share, dimension, cross-section, and annotate 3D files from most common formats. http://www.actify.com/
Develops the AutoVue family of programs to view and markup 2D/3D CAD and office formats. A thin/thick-client CAD viewer integrates with ERP, PLM, and document management systems. http://www.cimmetry.com/
A viewer for AutoCAD Drawing Web Format (DWF) and SVF, for redlining CAD drawings on any client platform via a web and Java based interface. http://www.cadviewer.com/
Viewing and markup software for a variety of document formats, drawings and images, including Java-based Web viewing, markup and collaboration. http://www.infograph.com/
Autodesk's web-enabled review and markup tool for engineering data, working with the DWG, DXF, DWF, and Inventor formats. http://www.autodesk.com/voloview