It is a part of the NI Circuit Design Suite, which also includes NI Ultiboard for PCB layout and design. NI Multisim, on the other hand, is a commercial circuit simulation and schematic capture software developed by National Instruments. LTSpice was described above and so not repeated here.

LTSpice and NI Multisim are both popular circuit simulators, but they have different features and capabilities. LTSpice is more specialized in simulating analog circuits, while Proteus offers a wider range of features and is more suitable for complete electronic design projects. In summary, LTSpice is a powerful and easy-to-use tool for simulating analog circuits, while Proteus is a comprehensive electronic design solution that includes circuit simulation, PCB layout, and microcontroller simulation. Proteus also has a built-in schematic editor and PCB layout editor, making it a complete electronic design solution. In addition, Proteus supports IoT(Internet of Things) projects which is not available in LTSpice. It also allows for the simulation of microcontroller-based circuits, which is not possible in LTSpice.

Proteus has a large library of components and models, including microcontroller models for popular microcontrollers such as Arduino, PIC, AVR, Raspberry PI and ESP8266.

It is a commercial software and offers a wide range of features for electronic design, including circuit simulation, PCB layout, and microcontroller simulation. Proteus, on the other hand, is a circuit simulation and PCB design software developed by Labcenter Electronics. It's also available for multiple platforms such as Windows, Mac and Linux. Additionally, LTSpice has a powerful built-in waveform viewer, which can be used to analyze the simulation results. It also has a user-friendly interface, making it easy to use for both beginners and experienced users. It has a large library of models and components, allowing users to simulate a wide variety of circuits. It is a free, powerful and easy-to-use tool for simulating analog circuits. LTSpice is a high-performance SPICE simulation program developed by Linear Technology, now part of Analog Devices. LTSpice and Proteus are both popular circuit simulators, but they have different features and capabilities.

Ni multisim arduino library