I envision a switchable client, specified by a URI in the response headers. The client would be a platform independent bytecode of some sort, like the NaCl. Th

I envision a switchable client, specified by a URI in the response headers. The client would be a platform independent bytecode of some sort, like the NaCl. The only thing the browser would supply would be the chrome, networking, sandboxing, and a canvas for the client to draw to. The current web runtimes could be refactored into one of these clients. If you don't like the way CSS works, or if you think JS is weird, just write another client.