FreeCAD - An open-source parametric 3D modeler
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
SketchUp - 3D for Everyone
ZBrush - ZBrush is a digital sculpting and painting software solution.
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.