When I think about this problem, I feel like there are 2 major priorities that tug from different ends of the spectrum on this issue. 1) I want innovation. I

When I think about this problem, I feel like there are 2 major priorities that tug from different ends of the spectrum on this issue. 1) I want innovation. I want new features for the web. I don't want innovation to be hampered by the priority of making features cross-browser compatible. 2) I want cross-browser compatibility. I don't want to have to develop N apps (N representing the total # of browsers my website / app supports). Personally I don't care if X browser has feature Y. As a developer, if I find a feature I want to program into my website / application, I don't want to have to wait for N-1 other browsers to implement this feature before I start using it. I want to be able to "declare" or send a "hint" in my HTTP headers (or meta tags?) telling the browser that my site is supported by X,Y,Z browser engines. Each browser would implement a bare bones interface that decouples the "chrome" of the browser window from the "application" window, and makes the application window interchangeable (plug n play) with other browser engines. This would make browser engines interchangeable without requiring a user to close one browser and open another. Granted, if a user doesn't have browser engine 'X', and refuses to download / install it, that's my loss as a developer / website owner. Or of course I could write some graceful degradation into my app / website. Already I hear some folks saying "but this is what we do now". Not quite. It's a subtle but I think important difference. Most people are willing to install (or already have installed) all major browsers on their computers. The point is, currently we must develop for / test for all major browsers to get the desired reach (or to prevent a user from having to switch browsers). This alternative approach moves the needle when a user installs a browser, not when they use the browser. So if there are a substantial # of people who have both Chrome / Firefox installed on their computers, but 'X'% of those people regularly use Firefox, I can still develop ONLY for Chrome and still get the desired reach into the world's population who have internet access. There are of course going to be pros / cons no matter what you do, but given the above priorities, and the predispositions of all actors involved (web browser developers, web browser users, website / web app developers) I really think this is going to be the most scalable, least intrusive / obstructive path forward.