I'd like to introduce couple more Sidelinesoft products related to NL5.
idealCircuit: an analog circuit simulator working with true ideal
components. Uses exactly the same unique and robust algorithm as NL5.
However, it is simplified as much as possible: very simple and
intuitive interface, fewer components and models, no fancy and powerful
features that are only useful for specialized applications.
ideal-Z: a simple impedance calculator with graphical schematic entry. Drop
components onto the schematic, connect them, set values, and the
impedance is calculated instantaneously. Also based on part of NL5 algorithm.