A small group of maintainers and the user community contribute to the ngspice project by providing new features, enhancements and bug fixes.

AC analysis includes small-signal noise simulation, pole-zero and transfer function analysis:[9] Ngspice implements various circuits elements, like resistors, capacitors, inductors (single or mutual), transmission lines and a growing number of semiconductor devices like diodes, bipolar transistors, MOSFETs (both bulk and SOI), MESFETs, JFETs and HFETs.

For mixed signal circuit simulation ngspice allows users to create a user-defined node definition file (UDN) of a new device model interface.

This permissive open source license allows its integration as a simulation engine into several — proprietary or free/libre — EDA tools such as KiCad,[10][11] EAGLE (program),[12] CoolSPICE, Altium and others.

An open source GUI with schematic entry, simulation and plotting is provided by Qucs-S. Ngspice progress was presented at FOSDEM[13] and FSiC conferences in 2019.