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 (http://www.kicad-pcb.org) and Ngspice (http://ngspice.sourceforge.net/). 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.
  • Do PCB design and generate Gerber files using KiCad.
  • Add/Edit device models and subcircuits using the Model Builder and Subcircuit Builder tools.
  • Runs on Ubuntu Linux and Windows.