Babylon.js/Playground/js/config_versions.js

CONFIG_last_versions = [
    ["Latest","https://preview.babylonjs.com/babylon.js"],
    ["4.0.3","https://unpkg.com/babylonjs@4.0.3/babylon.js"],
    ["4.0.0","https://unpkg.com/babylonjs@4.0.0/babylon.js"],
    ["3.0","https://unpkg.com/babylonjs@3.0.7/dist/preview%20release/babylon.js"]
];