SketchUp - 3D for Everyone
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.
FreeCAD - An open-source parametric 3D modeler
e-Builder - e-Builder is a construction program management solution that manages capital program cost, schedule, and documents.
AutoCAD Arch - Design and document more efficiently with the AutoCAD Architecture toolset, created specifically for architects.