An interactive whiteboard appliance includes the capability to instantiate and manage multiple windows on the interactive whiteboard appliance in a manner that allows information in multiple windows to be viewed concurrently by dynamically selecting and changing the opacity of one or more portions of a topmost window in response to one or more conditions. The one or more conditions may include one or more user actions made with respect to the topmost window or the one or more conditions may be related to a window other than the topmost window, such as detection of an audio signal in a non-topmost window. Opacity may be selectively changed on a region-by-region basis and graphical user interface controls may be provided to allow users to specify different opacity levels.