AutoCAD OwnerGuard 6.0.0
Protect Your Files Ownership Rights While Editing, Sharing or Selling on the Net
Acme CADSee 5.3
The fastest and easiest-to-use DWG DXF DWF and BMP PSD JPEG TIFF PCX TGA PNG MNG GIF WMF ICO file viewer available for Windows /98/ME/NT/2000/XP/Win7! AcmeCADSee is two tools in one.
AutoDWG DWGLock 2.8
DWGLock, Protecting drawing file, Keep others from modifying/copying your design
AutoQ3D CAD 5.10
AutoQ3D CAD is not a simple paint program, it's a full CAD application that let you make a lot of things in 2D & 3D.