FreeCAD - An open-source parametric 3D modeler
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
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.
SolveSpace - SOLVESPACE is a parametric 3D CAD program with extrude, revolve, union and difference functions.