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
myOpenLab - MyOpenLab is a platform for finished elements (program components) that can be linked together.
Solve Elec - Solve Elec is a free educational program to draw and analyze electrical circuits.
PyLab_Works - PyLab_Works is a free and open source replacement for LabView + MatLab, written in pure Python.
PCBWeb - PCBWeb is a 100% free Windows desktop CAD application for designing and manufacturing electronics...
LabVIEW - LabVIEW offers many of the functions you'd find in a traditional script-based programming language presented in a more intuitive visual interface ideal fo engineering.