DWGSee Pro is the professional and more complete version of
DWGSee. It is a tool that lets you view and move about the content of a DWG file without needing to install AutoCAD
Apart from being a viewer of these types of file, DWGSee Pro also lets you print them from its interface, convert them to other graphic formats like JPG, TIFF, GIF or even PDF, see thumbnail previews of the designs, add new and different layers to the original DWG, etc.
DWGSee Pro also lets you do batch processing of these DWG files.