RequireJS is a JavaScript file and module loader. It is optimized for in-browser use, but it can be used in other JavaScript environments, like Rhino and Node. Using a modular script loader like RequireJS will improve the speed and quality of your code.

From RequireJS

Third-Party libraries sometimes come without AMD version. This post introduces a method to wrap them using shim. I’m going to take Three.js as example. The file structure is shown below. three.js and three.EdgeShader.js are required in A.js, and the later of which depends on the former one.

index.html
    /vendor
        three.js
        three.EdgeShader.js
    /src
        /js
            A.js

In index.html, we use shim for three and threeEdge. The deps attribute of threeEdge denotes the dependence on three, and exports makes THREE and THREE.EdgeShader accessible elsewhere.

require.config({
    baseUrl: './src/js',
    paths: {
        'three': '../../vendor/three',
        'threeEdge': '../../vendor/three.EdgeShader',
    },
    shim: {
        'three': {
            exports: 'THREE'
        },
        'threeEdge': {
            deps: ['three'],
            exports: 'THREE.EdgeShader'
        }
    }
});

In A.js, they can be accessed by calling require('three') and require('threeEdge').

var THREE = require('three');
THREE.EdgeShader = require('threeEdge');