FreeCAD - An open-source parametric 3D modeler
Autodesk AutoCAD - Autodesk AutoCAD is a commercial computer-aided design (CAD) and drafting software application.
SketchUp - 3D for Everyone
LibreCAD - An open source 2D CAD application for Windows, Apple and Linux.
Redeye Apps - A common data environment to collect, manage and share engineering information
nanoCAD - nanoCAD is a pro-grade 2D CAD system with native DWG support and full customizability.