Calspex - Calibration
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
GageList - Simple online calibration software
Solve Elec - Solve Elec is a free educational program to draw and analyze electrical circuits.
QMSys GUM - Calibration
Oregano - oregano - An electrical engineering tool for GNOME