This actually displays one of the issues i have with global script as a concept, you are basically just doing
<iframe src="..."></..>
And that gives you a context that achieves almost everything the global script concept gives you.
People keep saying that this is no better than a new window or an iframe because you can script those synchronously across pages, but that totally misses the point. The the frame/script/window survives when it's parent page is closed if there's another page pointing to it and, in some versions of this proposal, it survives same-origin page navigations. That isn't true of iframes or windows and is exactly what makes these useful.
This is exactly right, the most interesting aspect is its lifetime that makes it a nice place to call 'the application'. It can keep the app state while pages navigate between each other, making browser history and page cache just work. And it can make windows independent of each other without loading the whole app in each of them...
There was an i
nteresting presentation from Facebook folks at O'Reilly Velocity conference (
pdf slides here) where they describe 'quicklings' - the elaborate way to avoid full page loads. Also they try to cache as much as possible in the 'live' form in memory - so they can keep those fast caches up to date. This is similar to what many applications are doing today - trying to keep a single 'main' page alive and inventing their incarnations of navigation and history. Global Script could be useful there as a replacement for those ad-hoc mechanisms.
Dmitry