ngspice: ngspice (circuit simulator)
ngspice: 
ngspice: Ngspice is a mixed-level/mixed-signal circuit simulator. Its code is
ngspice: based on three open source software packages: Spice3f5, Cider1b1 and
ngspice: Xspice.
ngspice: 
ngspice: 
ngspice: 
ngspice: 
ngspice: 
ngspice: