LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
FreeCAD - An open-source parametric 3D modeler
SketchUp - 3D for Everyone
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.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
DraftSight - Discover Dassault Systèmes®' DRAFTSIGHT™ Professional CAD software that lets you create, edit, view and markup any kind of 2D drawing. Learn more here.