CAD Viewer 1.0 by 341Mac is an interesting tool that does what its name indicates: it opens CAD files for viewing. It works with major CAD programs like Autocad, and it supports most CAD and related file formats. It offers a nimble, lightweight and, most significantly, free alternative to those huge pro CAD packages, which are among the most complex and expensive software you can buy.
CAD Viewer is a small download at 1.25MB, yet it has its own installer with automatic online updating. It has a simple, attractive, and uncluttered interface with a look that recalls Mac-based software, perhaps a nod to the proclivities of the Thai developer, "341Mac." The interface consists of nothing more than a viewing pane in a dialog box with a file menu and a toolbar containing command buttons for manipulating 2D and 3D CAD images. The "Help file" is just a pop-up with some keystroke commands and instructions for making donations. However, CAD Viewer is easy to figure out, though you need to have files in one of the half-dozen CAD formats it supports to use it. You can rotate 3D objects in X, Y, and Z axes, output to a conventional printer or a plotter, and, best of all, easily save images as JPEGs. This last feature makes CAD Viewer uniquely versatile and useful to many who need to use CAD images but don't have the tools.
CAD Viewer is freeware, and it works in all versions of Windows from 95 to 7.