Behold the inexorable advance of the Atwood Law.
Next step would be having an ability to entirely reprogram the layout engine in newly-performant JS. And then more and more, until we have built an entire OS (again).
Next step would be having an ability to entirely reprogram the layout engine in newly-performant JS. And then more and more, until we have built an entire OS (again).
That's what Google Docs switched to so they could guarantee a consistent UI across different browser platforms.
For the full OS implementation see NodeOS and Runtime.js. NodeOS is a V8 runtime built on top of a very minimal linux kernel. Runtime.js is a full OS implementation from scratch written entirely in Javascript.