LTspice is a free, high-performance SPICE simulator, schematic capture, and waveform viewer with an impressive library of passive and active devices. It is available for Windows, macOS, and Linux. It has a powerful command line interface and can be used to simulate a variety of circuits including analog, digital, and mixed-signal circuits. It is also used to create waveforms for waveform analysis.

Multisim

Multisim is a powerful SPICE-based circuit simulation software. It is designed to help engineers analyze and design analog, mixed-signal, and RF circuits. Multisim comes with a wide range of components, including capacitors, transistors, and operational amplifiers, as well as a powerful set of analysis tools. It also offers a graphical user interface that is easy to use and understand.

CircuitLab

CircuitLab is a powerful online circuit simulator that enables users to quickly create and simulate their own circuits. It includes a wide range of components, including resistors, capacitors, and transistors, as well as powerful analysis tools. The user interface is intuitive and easy to use, making it a great alternative to LTspice.

KiCad

KiCad is a free and open-source EDA software that offers a straightforward learning curve, a wide array of components and powerful analysis tools, and a simple graphical interface, making it a great choice for both hobbyists and professionals.

Autodesk Eagle

Autodesk Eagle is a professional-grade EDA software used to design printed circuit boards. It boasts a vast array of components, powerful analysis tools, and a user-friendly graphical interface. Autodesk Eagle is designed for experienced users, as it has a learning curve and may be difficult to learn for beginners.

EasyEDA

EasyEDA is an ideal solution for hobbyists and professionals alike, offering free cloud-based EDA software for circuit board design. This software boasts a user-friendly interface, a wide range of components, and powerful analysis tools, making it a good alternative to LTspice.