In most cases these are separate apps. "Just build it twice!" is necessary in some cases, but is far from idea. Progressive enhancement is hard, at least for c

In most cases these are separate apps. "Just build it twice!" is necessary in some cases, but is far from idea. Progressive enhancement is hard, at least for complex interfaces that need to maintain state. Hard enough that many sites, if they support disabling JS at all, do so by writing an entirely new frontend with a simplified feature set. Ember + Fastboot provides many of the advantages of progressive enhancement, but is far more productive in many cases.