That's a multipart response [0]. In the early days of 3G (and multimedia phones) we used to use those for some models of phone which supported it to give a better browsing experience - the gamble being that more downstream data would be faster than costing a request / response round-trip if you were pretty confident that the phone was going to ask for it.

[0] http://stackoverflow.com/questions/1806228/browser-support-o...

Assuming those requests are sent in order, that could be an interesting optimization!

> Assuming those requests are sent in order

That's the problem right there. Right off the bat I don't see how to get around that one.

They'd also have to be all on the same connection. Also, you'd lose out on caching.

At that point you might as well just inline the css and javascript.

Dynamically generated unique hostnames per resource would work.

I'm probably missing something but... wouldn't all the extra dns lookups remove most of the speed advantage?