KiCad - A Cross Platform and Open Source Electronics Design Automation Suite
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Proteus PCB design - Proteus PCB design combines the schematic capture and ARES PCB layout programs to provide a...
Vectorworks - Vectorworks 2D / 3D CAD and BIM software for Mac or Windows provides one flexible solution for your entire design process. Sketch, model, and present with the ultimate software from start to finish.
QUCS - Qucs, briefly for Quite Universal Circuit Simulator, is an integrated circuit simulator which means you are able to setup a circuit with a graphical user interface (GUI) and simulate the large-signal, small-signal and noise behaviour of the circuit.
ArCADia-Architecture - ArCADia-Architecture is a revolutionary component for the instant creation of architectural documentation and object drawing.