OpenSCAD - OpenSCAD is a software for creating solid 3D CAD objects.
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.
SketchUp - 3D for Everyone
BRL-CAD - BRL-CAD: Open Source Solid Modeling
FreeCAD - An open-source parametric 3D modeler