SketchUp - 3D for Everyone
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
Autodesk Revit - Autodesk Revit is building information modeling software for architects, structural engineers, MEP engineers, designers, and contractors.
FreeCAD - An open-source parametric 3D modeler
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.