For the back-end: Everything that's required for correctly rendering or executing modern web content (i.e., everything that's mandated by the current snapshot of the HTML living standard plus non-HTML formats which are "de-facto" part of the web, like Flash and PDF).
For the UI: Stuff that can be expected to make the task of browsing web pages easier for the average user.
Neither Hello nor Pocket fit any of the above descriptions.
For the back-end: Everything that's required for correctly rendering or executing modern web content (i.e., everything that's mandated by the current snapshot of the HTML living standard plus non-HTML formats which are "de-facto" part of the web, like Flash and PDF).
For the UI: Stuff that can be expected to make the task of browsing web pages easier for the average user.
Neither Hello nor Pocket fit any of the above descriptions.