The new fangled Metro UI demoed on Windows 8 has a lot of dependence on the IE 10 architecture. Even though it is not necessarily a browser or a separate app running on top of the normal explorer, it is still heavily dependent on Internet Explorer 10
Metro UI Is Based On IE10 Engine
The Metro UI is not a layer on top of the normal Windows Explorer. It is an option that you can go in and out of while using Windows 8. However, it’s UI elements and apps are all running on the IE 10 engine.
Media Queries In IE 10
Media Queries, introduced in IE9, allows for a page to be dynamically resized according to the display area and page. This is not a zooming in and out of the page. The page content is actually reflowed and individually reorganized in order to make it fit.
This implementation can be seen in the IE demo where a grid of pictures turn to a stack and lose their captions and other frills in order to fit in to a narrower setting. The same can be seen in the news app in the Windows 8 demo, where the content is reflowed and images change from mere thumbnails with one link to large images with caption and multiple links as it is resized.
It can also change as per the orientation — showing the focus on mobile devices.
Desktop With Grid Layout
The Grid layout is another feature that is implemented for both the web and Windows 8 UI. Here, the grid makes sure that relevant elements are all properly aligned and the whole grid does not shrink or grow uniformly. Individual flexiboxes resize differently in order to have a contextual layout.
Overall, if you are looking in the right places, the interconnections between the browser and the UI are quite noticeable.