AutoCAD: The most popular tool you can use
A Great free AutoCAD Drawing Viewer
A free and powerful 3D modeling software
A free, powerful 2D and 3D CAD tool
AutoCAD
GstarCAD (64-Bit)
More stable and faster, GstarCAD 2016 is an optimized CAD platform to save countless hours of design and rework
AutoDWG DWGSee
View CAD files in DWG, DXF and DWF formats
Free DWG Viewer
A free program to show AutoCAD files