SketchUp - 3D for Everyone
FreeCAD - An open-source parametric 3D modeler
Assetforge - Asset Forge allows anyone to create 3D models and 2D sprites using building blocks.
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
ArchiCAD - ArchiCAD 16 enables BIM modeling with a new green approach to planning. Create anything you need with ArchiCAD's flexible new features for design.
Autodesk AutoCAD - Autodesk AutoCAD is a commercial computer-aided design (CAD) and drafting software application.