Here's a future tech to keep an eye on: the "seamless" attribute for iframes. (WhatWG spec) It basically acts as a client-side include for HTML code (and so, really, isn't much like a frame at all). So, just as we've always done server-side, we can now ("now," meaning "lord knows when"... browser support ugh) break a page into fragments and serve each portion from a different URI, which are recombined by the browser. This gives us great control over caching and distribution. We could, for example, use a frame for the navigation that is served from a CDN and refreshed only every 24 hours, and one for an article content that caches for one hour (in case of updates), and one for social media stuff that is never cached. Unlike with regular iframes, all of this can happen within one DOM space, sharing styles, scripts, etc.