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, GHDL, OpenModelica, Verilator, Makerchip, and SkyWater SKY130 PDK. eSim is released under GNU General Public License.
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, PSpice, LTspice, 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 modeling software.


Activities under eSim

The following are the activities under eSim. Please feel free to participate and contribute.

Please visit the FOSSEE website for more details.

Join Hands with eSim!!!


eSim being an OpenSource Software needs help from people. We are very much looking forward to hearing from you all. Please feel free to contribute, report bugs/issues, give feedback, create pull requests, etc.
Please contact us by visiting here


We are Ready to Help, and to be Helped!!!