Energy2D is an interactive multiphysics simulation program grounded in computational physics, designed to model the three primary modes of heat transfer: conduction, convection, and radiation, while also integrating particle dynamics. This software operates efficiently on a wide range of computers, simplifying the process by removing the need for switches between preprocessors, solvers, and postprocessors that are usually necessary for computational fluid dynamics simulations. Users can create "computational experiments" to explore scientific hypotheses or address engineering challenges without the need for intricate mathematical formulations. Additionally, development is ongoing to introduce various energy transformation types and to enhance support for different fluid types. While Energy2D excels in accurately modeling conduction, its representations of convection and radiation are not entirely precise, which means results involving these elements should be regarded as qualitative. Over 40 scientific papers have utilized Energy2D as a valuable research instrument, showcasing its adoption in the academic community. As the program evolves, its capabilities are expected to expand further, potentially offering more comprehensive insights into complex physical interactions.