RISA-3D - Structural Analysis and Design
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Etabs - For nearly 30 years, ETABS has been recognized as the industry standard for Building Analysis and...
FreeCAD - An open-source parametric 3D modeler
midas Gen - Structural Analysis and Design
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.