The iPad may be "magical," but future Winpads will be "immersive."
Understanding what Microsoft means when it invokes the "I" word is going to become increasingly important to Windows developers (and to a lesser extent, users), in the not-too-distant future.
There have been some recent leaks that indicate Windows 8 may include a Ribbonized Windows Explorer or a possible Metro-inspired Windows 8 lock screen. However, relatively little is still known about the Windows 8 interface at this point in the development schedule.
In spite of any official Windows 8 word, it has been rumored for a while now that Microsoft will be offering two different interfaces with Windows 8. One, allegedly, will be a tiled interface (similar to the tiled Metro/Windows Phone UI). This interface is believed to be MoSH (Modern Shell). Supposedly, this will be the primary (if not sole) interface for Windows 8 tablets and slates. The second interface will be more of a classic Windows Shell and will be the UI for Windows 8 desktops and non-touch-centric Windows PCs.
(Along with a number of other bloggers, pundits and users, I have wondered why Microsoft didn't simply use its Windows Phone OS and Metro tiled UI -- rather than Windows 7 and 8 -- as its tablet/slate OS. The answer, it seems, is company officials are attempting to provide the same Windows Phone "look and feel," keeping Windows, rather than a different operating system, the focal point.)
"Immersive" is the way that Microsoft is describing the Windows 8 app experience on tablets and slates running the MoSH interface, from what I've been told. Inside the company, some Softies use "immersive" and "modern" or "modern client" apps as synonyms. Once a user installs an immersive application, a tile for it will appear on the user's Windows 8 dashboard.
An immersive app is one where the navigational elements of the operating system take a back seat to the application itself. Think about the difference between the New York Times iPad app and the New York Times Web site on the iPad. The first of these is an example of an immersive app, while the second is simply a Web experience. With an immersive app, all the UI controls for a particular app look and feel like native shell inside the app. In other words, a user is "immersed" in the app that s/he is running at any given time.
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?
The "immersive" concept is connected to the "Jupiter" application model that is being developed alongside Windows 8. As a few bloggers with access to information about internal Microsoft Windows 8 builds have noted recently, the Milestone 2/3 builds of Windows 8 include references to "immersive" inside the operating system itself.
Jupiter -- a new UI library for Windows 8 -- is believed to be what will enable "immersive" applications to be deployed as AppX packages (.appx). Visual Studio 2012 supposedly will support the creation of thesee kinds of applications, which can be written in C#, Visual Basic and C++. Jupiter-based immersive apps will be delivered via the Windows 8 App Store, according to the grand Microsoft plan, my contacts have said.
Immersive apps aren't about Web vs. Windows. The high-level idea is they'll be a blend of Web and Windows.
Update: Rafael Rivera of WithinWindows has more on what "immersive" means from the Win 8 UI standpoint in an April 4 on his blog.