Blender - Blender is the open source, cross platform suite of tools for 3D creation.
FreeCAD - An open-source parametric 3D modeler
SelfCAD - SelfCAD is an online 3D modeling and slicing software.
OpenSCAD - OpenSCAD is a software for creating solid 3D CAD objects.
SketchUp - 3D for Everyone
Autodesk AutoCAD - Autodesk AutoCAD is a commercial computer-aided design (CAD) and drafting software application.