Just thinking out loud here: What if we had a "meta app" which encapsulated individual browsers and created a specification allowing developers to define which

Just thinking out loud here: What if we had a "meta app" which encapsulated individual browsers and created a specification allowing developers to define which browser type to use when opening their web page? Not saying this can't be done today, but where the transition was seamless. I'm unaware of anything that allows us to do this today. I do recall a project that allowed one to do something similar (IE tabs in Chrome), but I think it wasn't the same in terms of seamless transition, and there was no way for the developer to control the transition.