Quite a while ago I had users complaining they could not use my application from another secure network zone. It appeared the root cause was in using Yahoo CDN for serving YUI resources while there was no internet access in that specific network zone. Also living behind a proxy, our regular users used to suffer from longer delays from time to time due to proxying. An obvious solution turned out to be using a locally served YUI. For this a combo loader is required if you care about efficiency on Production. Installation To start with, there are several alternative open-source tools that can be used for combo loading: Official PHP loader by Yahoo – is obsolete and is said not to work with any version over 3.3.0. CGI script combo – I cannot say much about it besides that it's 3 years old. Node.js combo handler – is kept updated and is the one that I decided to use. The Node.js combo handler is supplied with rather self-contained README file at github. Nevertheless, I&#