Most of the Pinguino boards or extensions are designed with Kicad.

KiCad is an EDA software suite for the creation of professional schematics and printed circuit boards up to 16 layers. KiCad runs on Windows, Linux and Apple OS X and is released under the open-source GNU GPL v2 free of charge. With Kicad you can do the following :

• Schematic design.
• Netlist creation in multiple formats (PCBNew, OrCAD, CadStar, Spice, etc...).
• PCB design
• 3D visualization of your PCB
• Fabrication outputs generation (Gerber, drill files and whatever can be needed to manufacture a PCB.)

For a more detailed explanation please refer to the official site : http://www.kicad-pcb.org

For a better result we use libraries, modules en 3D packages from Walter : http://smisioto.no-ip.org/elettronica/kicad/kicad-en.htm