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.
FreeCAD - An open-source parametric 3D modeler
SketchUp - 3D for Everyone
Autodesk AutoCAD - Autodesk AutoCAD is a commercial computer-aided design (CAD) and drafting software application.
Rhino 3D - To be an effective designer today, you need tools to quickly develop your designs and accurately communicate them to everyone in the product research.