Mathematica's system information display (click Help>AboutMathematica>SystemInformation to see it) is nicely packaged. Is it just a notebook with a TabView and other controls in a notebook with options set to size it just larger than the controls? Does it take any special tricks to keep the functions hidden and make it work the way it does?
This occured to me after having asked the base question, which was really about interface mechanisms. Couldn't System Information be written as a CDF? (I realize these are two unrelated questions)
CreateDialogyou can turn a tab view, or a manipulate, or whatever you are used to seing embedded in a document, as a dialog looking notebook, something that "looks like an application" – Rojo Nov 26 '12 at 02:41