Run Ensemble as a web app (http://download.oracle.com/otndocs/products/javafx/2.2/samples/Ensemble/index.html). When the app is running and focus is somewhere in the browser it is not possible to navigate to the app by using TAB key. Similarly, when focus is in the app it is not possible to move focus to the browser (e.g. URL field).

Note that TAB key should allow users to navigate across all UI.