Free DWG Viewer 

Free DWG Viewer will open native DWG, DXF, and DWF files for viewing, along with accompanying Xref files. It will also open Informative Graphics' own "content sealed" (CSF) file format, which is generated by the company's Net-It publishing products
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Terrain for AutoCAD 

Terrain for AutoCAD is a terrain modeling plug-in for AutoCAD. This plug-in gives AutoCAD the ability to create a terrain mesh from a set of unordered points.
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AHatch Pro 

AHatch Pro is a flexible tool for the design of Autodesk AutoCAD hatch patterns. The generated hatch patterns can be used with the AutoCAD "hatch" and "bhatch" commands. AHatch Pro is developed as a stand-alone program.
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