Qucs-S is a free and open source integrated circuit simulator for Linux and windows. It is released under open source GPL-2.0 License. It is a spin-off of the popular circuit simulator Quite Universal Circuit Simulator (QUCS). It is using the SPICE circuit simulation kernels with the Qucs GUI. It supports all Qucs component types and simulations
Direct support of SPICE models from components datasheets. Supported SPICE components are RCL, BJT, MOSFET, JFET, MESFET, switches, Equation-defined sources and RCLs, transmission lines. And it also supports SPICE Modelcards, SPICE sections, Parametric circuits, SPICE postrprocessor and lot more.