Blender - Blender is the open source, cross platform suite of tools for 3D creation.
FreeCAD - An open-source parametric 3D modeler
MakeHuman - MakeHuman is a free, open source, interactive modeling tool for creating custom 3D human characters.
SolidWorks - Dassault Systèmes SolidWorks Corp. develops and markets 3D CAD design software, analysis software, and product data management software. SolidWorks is the leading supplier of 3D CAD product design engineering software.
Bforartists - Bforartists is a fork of Blender.
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.