title: Why doesn't Facebook combine its CSS/JS files?
body: <p>I am curious as to why the Facebook developers have chosen to not combine their scripts and stylesheets into single files. Instead they are loaded on demand via their CDN.</p>
  
  <p>Facebook is obviously a very complex application and I can understand how such modularity might make Facebook easier to maintain, but wouldn't the usual optimisation advice still apply (especially given its high level of usage)?</p>
  
  <p>Or, does the fact that they are using a CDN avoid the usual performance impact of having lots of small scripts / styles?</p>