SketchUp - 3D for Everyone
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
DraftSight - Discover Dassault Systèmes®' DRAFTSIGHT™ Professional CAD software that lets you create, edit, view and markup any kind of 2D drawing. Learn more here.
FreeCAD - An open-source parametric 3D modeler
MicroStation - 3D CAD modelling software for architecture and engineering.
TurboCAD - TurboCAD is a CAD software suite, with several different feature levels.