KiCad - A Cross Platform and Open Source Electronics Design Automation Suite
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.
Fritzing - Fritzing is an open-source initiative to support designers, artists, researchers and hobbyists to...
Circuit Simulator - Animated electronic circuit simulator using ideal components to visualize voltage and current.
Solve Elec - Solve Elec is a free educational program to draw and analyze electrical circuits.
Autodesk EAGLE - Autodesk EAGLE is an electronic design automation (EDA) software.