Asynchronous Require

You can use the asynchronous (array) version of require require(['...'], function(){...}), anywhere you like, Web/AMD or nodejs (and of course UMD, <script/> etc.

Keep in mind that the asynchronous require is essentially the only proper way to conditionally load 'myHugeButOptionalModule' on the Web/AMD side. For instance,

if (true) {// perhaps some code here,
        // to conditionally call asynch 'require' bellow
  require(['depdir/dep1', 'depdir/dep2'], function(dep1, dep2) {
    // module factory function
    // called asynchronously & after dep1 & dep2 are loaded
    // module returned here
  });
}
// code here is executed immediately after calling `require`,
// BEFORE calling the factory function, since its asynchronous.

The asynch require always runs asynchronously on nodejs, just like it does on Web RequireJS/AMD.

Note: versions of RequireJS < 2.1.x were not consistent on the asynchronous call of require(['dep1', 'dep2'], fn): if all your dependencies ['dep1', 'dep2'] had already been loaded/cached before, the call to fn was actually synchronous. uRequire now matches the behaviour of the latest RequireJS (always asynch).