In-Lining CSS on First Page View

[pmeenan]

Depends on how big your CSS is.

It's a fairly old technique that works well (I believe Yahoo was one of the first to do it ~8-10 years ago). You can generalize it by having a hidden iFrame that you load after onload that is used to cache critical resources and have that frame request set a cookie (including the version of the cached bundle). Then on page views if the cookie is present you don't inline (or include the pre-caching code) and if the cookie is not present you do the inline hop.

As you mention, even in the case where the files are cleared but the cookies are not (rare) nothing breaks, it is just slower because it has to load the external resources like it would have if they weren't inlined.