KiCad - A Cross Platform and Open Source Electronics Design Automation Suite
DeleD CE - DeleD is a 3D modeler and level-editor combined into one.
Proteus PCB design - Proteus PCB design combines the schematic capture and ARES PCB layout programs to provide a...
Pmx Editor - PMX Editor is for editing 3D model data to be used in MikuMiku Dance.
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.
Sunny 3D - With ultimate simple user interface, you can create 3D model by using freehand sketch and directly...