The following chapter describes an offer to the advanced user and developer community. If you are interested in evaluating the parallel and synchronized operation of several ngspice instances, this may be one way to go. However, no ready to use implementation is available. You will find a toolbox and some hints how to use it. Parallelization and synchronization is your task by developing a suitable caller! And of course another major input has to come from partitioning the circuit into suitable, loosely coupled pieces, each with its own netlist, one netlist per ngspice instance. And you have to define the coupling between the circuit blocks. Both are not provided by ngspice, but are again your responsibility. Both are under active research, and the toolbox described below is an offer to join that research.