[gbhn]

For better or worse, the way software delivery has evolved on the web is that documents contain applications.

I think that if we had known where we wanted to go, it may have been better to start the other direction, and make a web app API that basically allowed apps to contain documents. That would have avoided significant amounts of pain, and ended up looking more similar to what we have anyway -- web apps wanting or needing a larger and larger degree of extension-like autonomy and permission sharing with the browser.