Ammo.js is a JavaScript port of the Bullet Physics engine (version 2.82) compiled via Emscripten. It provides a full 3D physics simulation library for browsers and Node.js, supporting rigid bodies, soft bodies, constraints, vehicles, collision detection, and more. The repository bundles the entire Bullet source tree (C++), along with JavaScript glue code (ammo.h, ammo.idl, onload.js) that defines the WebIDL bindings and initializes the WebAssembly/asm.js module. The library is consumed via a global `Ammo` object and is used in WebGL games and simulations. External examples include Three.js integration and several standalone WebGL demos. The build system uses Docker and CMake to invoke Emscripten. While the core Bullet physics library is mature and well-tested, the ammo.js wrapper itself shows signs of low maintenance (package version 0.0.2, 175 open issues, and an old vendored Bullet release). The codebase is large due to the included Bullet extras (demos, GPU acceleration, serialization) which are not directly related to the JavaScript port.