AutoCAD is a Computer Aided Drafting program made by Autodesk. AutoCAD is designed for drafting and 3D modeling, and it has the ability to create extreamly prcise drawings. For my use in Maze building, I use AutoCAD for both 2D and 3D drawings. For the engineer this is the ideal program for creating drawings. The 3D modeling features of AutoCAD are similer to that of Google SketchUp in their base form, but AutoCAD has the ability for much more complex and intricate drawings.