FreeCAD - An open-source parametric 3D modeler
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
OpenSCAD - OpenSCAD is a software for creating solid 3D CAD objects.
Autodesk AutoCAD - Autodesk AutoCAD is a commercial computer-aided design (CAD) and drafting software application.
Sculptris - Sculptris: Enter a world of digital art without barriers.
BRL-CAD - BRL-CAD: Open Source Solid Modeling