EasyEDA - EasyEDA - Web-based EDA suite; runs in browser.
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.
KiCad - A Cross Platform and Open Source Electronics Design Automation Suite
TINACloud - Create Simulate and Design Circuits and their PCB layout with TINACloud
Ngspice - Ngspice is a mixed-level/mixed-signal circuit simulator.
Proteus PCB design - Proteus PCB design combines the schematic capture and ARES PCB layout programs to provide a...