eSim (previously known as Oscad / FreeEDA) is a free/libre and open source EDA tool for circuit design, simulation, analysis and PCB design. It is an integrated tool built using free/libre and open source software such as KiCad, Ngspice, Verilator, Makerchip, GHDL and OpenModelica. eSim is released under GPL.

eSim offers similar capabilities and ease of use as any equivalent proprietary software for schematic creation, simulation and PCB design, without having to pay a huge amount of money to procure licenses. Hence it can be an affordable alternative to educational institutions and SMEs. It can serve as an alternative to commercially available/licensed software tools like OrCAD, Xpedition and HSPICE.


Features of eSim


  • Draw circuits using KiCad, create a netlist and simulate using Ngspice.
  • Design PCB layouts and generate Gerber files using KiCad.
  • Add/Edit device models(Spice Models) and subcircuits using the Model Builder and Subcircuit Builder tools.
  • Perform Mixed-Signal Simulation.
  • Support for Ubuntu and Windows OS.
  • Interface with OpenModelica modelling software.