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
VeroRoute - Cross-platform software for producing Veroboard (stripboard), Perfboard, and single-sided PCB...
Circuit Simulator - Animated electronic circuit simulator using ideal components to visualize voltage and current.
KiCad - A Cross Platform and Open Source Electronics Design Automation Suite
DIYLC - Free multi-platform schematic, layout and guitar wiring diagram editor
BlackBoard Circuit Designer - Help building prototypes on so called breadboards easily