Microsoft watcher Mary-Jo Foley reports Windows 8 will use LowBox, a sandbox environment with five different security "buckets".
Immersive apps, from a developer standpoint, are those which will conform to the new Windows App Model that will be built into Windows 8. Immersive apps will adhere to Windows 8’s conventions around registration, package composition and software state. These kinds of apps will run in the Windows 8 “LowBox,” which is the new Windows 8 security sandbox, I’ve heard.
With Windows 8, Microsoft developers are thinking about different types of apps and experiences as being in different buckets, I’m hearing from my contacts. Web apps (I’m assuming HTML5-compatible ones) are considered “Bucket 3″ apps. Immersive apps are “Bucket 4.” Legacy or “classic” managed and native apps are considered “Bucket 5.” What are in buckets 1 and 2? So far, I don’t know. Anyone?