The mod_pagespeed service does some of these optimisations (plus others). It's almost certainly applying JS concatenation, and in the end there's not much diff

The mod_pagespeed service does some of these optimisations (plus others). It's almost certainly applying JS concatenation, and in the end there's not much difference in load time: http://www.webpagetest.org/result/121024_K0_78b60a17cae988da846285d8e3d1f75c/ http://www.webpagetest.org/result/121024_K0_78b60a17cae988da... EDIT: Actually, it is applying some concatenation, but it's not concatenating everything: http://www.webpagetest.org/result/121024_35_049258ec5056f5b4b03f839edbe0d773/1/details/ http://www.webpagetest.org/result/121024_35_049258ec5056f5b4...