Pspice - OrCAD PSpice technology provides the best, high-performance circuit simulation to analyze and refine your circuits, components, and parameters before committing to layout and fabrication
Solve Elec - Solve Elec is a free educational program to draw and analyze electrical circuits.
Circuit Simulator - Animated electronic circuit simulator using ideal components to visualize voltage and current.
Oregano - oregano - An electrical engineering tool for GNOME
VeroRoute - Cross-platform software for producing Veroboard (stripboard), Perfboard, and single-sided PCB...
BlackBoard Circuit Designer - Help building prototypes on so called breadboards easily