Ngspice Alternatives

LTspice® is a high performance SPICE simulation software, schematic capture and waveform viewer with enhancements and models for easing the simulation of analog circuits.

Proteus PCB design combines the schematic capture and ARES PCB layout programs to provide a...

OrCAD PSpice technology provides the best, high-performance circuit simulation to analyze and refine your circuits, components, and parameters before committing to layout and fabrication

Qucs, briefly for Quite Universal Circuit Simulator, is an integrated circuit simulator which means you are able to setup a circuit with a graphical user interface (GUI) and simulate the large-signal, small-signal and noise behaviour of the circuit.

A Cross Platform and Open Source Electronics Design Automation Suite

Altium offers a top-notch, best-in-class PCB Designer to give engineers the tools they need to interlink with each side involved in the electronic design process.

KTechLab is an IDE for microcontrollers and electronics.

Animated electronic circuit simulator using ideal components to visualize voltage and current.

Multisim is industry standard SPICE simulation and circuit design software for analog, digital, and power electronics in education and research.

As IC geometries continue to shrink, the need for an accurate circuit simulator is critical.

Upverter makes it easy to design and share electronics on the web.

Proteus - Proteus is a great electrical suite for circuit simulation purposes. You can simulate a single processor or multiple ones at the same time. The application is a great alternative for Virtual System Modelling.

EasyEDA - Web-based EDA suite; runs in browser.