LTspice - LTspice® is a high performance SPICE simulation software, schematic capture and waveform viewer with enhancements and models for easing the simulation of analog circuits.
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
Proteus PCB design - Proteus PCB design combines the schematic capture and ARES PCB layout programs to provide a...
Solve Elec - Solve Elec is a free educational program to draw and analyze electrical circuits.
PCBWeb - PCBWeb is a 100% free Windows desktop CAD application for designing and manufacturing electronics...
QUCS - Qucs, briefly for Quite Universal Circuit Simulator, is an integrated circuit simulator which means you are able to setup a circuit with a graphical user interface (GUI) and simulate the large-signal, small-signal and noise behaviour of the circuit.