The Advanced Framework for Simulation, Integration, and Modeling (AFSIM) is a government-developed modeling and simulation environment designed for rapid scenario composition across engineering, engagement, mission, and campaign-level analysis. Originally developed for the Department of the Air Force, AFSIM is now used across the Department of War, government, industry, and research communities to model complex, multi-domain environments spanning the seafloor to space, including cyber. Its modular, extensible architecture enables users to integrate emerging technologies, evaluate system performance, explore operational concepts, and conduct mission-level analysis across increasingly complex battlespaces.