Logisim
Digital
LTspice
BOOLR
Logicly
Fritzing
Circuit Simulator
CircuitVerse.org
ModelSim
Synopsys VCS
Cadence Incisive
Riviera-PRO
gEDA Project
VCS
Proteus PCB design
Circuit Simulator
Logisim ModelSimDigital - A simulator for digital circuits.
Synopsys VCS - HDL Simulator of System Verilog, Verilog, and VHDL for ASIC design and verification.
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.
Cadence Incisive - System Verilog, Verilog, VHDL, SystemC HDL Simulator for ASIC Design and Verification
BOOLR - Open-source digital logic simulator
Riviera-PRO - System Verilog, Verilog. VHDL, SystemC, HDL simulator targeting ASIC and large FPGA designs.