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.
Logisim - Logisim is an educational tool for designing and simulating digital logic circuits.
Circuit Tree - Design and order Boards in Minutes
BOOLR - Open-source digital logic simulator
Circuit Simulator - Animated electronic circuit simulator using ideal components to visualize voltage and current.
Logicly - - Design circuits quickly and easily with a modern and intuitive user interface with drag-and-drop...