LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
SketchUp - 3D for Everyone
FreeCAD - An open-source parametric 3D modeler
Arena - Chess GUI Arena
PTC Creo Sketch - Creo Sketch is an easy to use 2D CAD application for capturing and creating new 2D freehand concepts which is available on PCs, Macs, and iPads.
Autodesk AutoCAD - Autodesk AutoCAD is a commercial computer-aided design (CAD) and drafting software application.