Falstad Simulator |link|

The Falstad Circuit Simulator is a widely-used, open-source electronic circuit simulation program developed by Paul Falstad. It is distinguished by its implementation in Java (and later JavaScript), allowing it to run directly in a web browser. Unlike traditional SPICE-based simulators that focus on numerical analysis and complex prototyping, Falstad emphasizes real-time, interactive visualization of voltage and current flow. It serves as a premier educational tool for students, hobbyists, and educators seeking to understand the fundamental behavior of circuits intuitively.

The UI is divided into three main sections: falstad simulator