LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
SketchUp - 3D for Everyone
DeltaCAD - Powerful, easy to learn 2D CAD (Computer Aided Design) program designed to meet all of your CAD...
FreeCAD - An open-source parametric 3D modeler
QCAD - QCAD is an application for computer aided drafting in 2D.
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.