Fakenode is a hack that can be used along with resolverjs (search on NPM) to allow a Javascript file running under NodeJS or in the browser

fakenode.js

// sluu99 (C) 2013
// Released under WTFPL
// Fakenode version 0.0.1
window.require = function(x) {
    if (x === 'resolverjs') {
        return {
            get: function(x, defaultVal) { return defaultVal; }
        };
    }

    return undefined;
}

/** Usage:
 * This file is meant to be used in the browser with a <script> tag.
 * Combine this with the resolvejs package (https://npmjs.org/package/resolverjs) to use modules that
 * can work on both NodeJS and the browser:
 *
 * Example:
 *
 * var resolver = require('resolverjs'); *
 * // If we are in the browser, then MyValidator should already be present from a <script> tag
 * var klass = (typeof(MyValidator) === 'undefined')? null : MyValidator;
 * var validator = resolver.get('libs/validator', klass);
 *
 */