Samsung's recent Android 4.1.2 upgrade for the Galaxy Note 10.1 adds power and flexibility to the company's unique offering of Android multiwindowing features From OSNews:

With this update, the Galaxy Note 10.1 can run up to 16 multiwindow-enabled Android apps at once, Windows/Mac-like, on a single screen. Apps endowed with Samsung's multiwindow technology are usable in three viewing modes: full screen, dual view, and cascade view.

 Samsung adds multi-window to its Android devices