Digital shadowing when rendering visual items (e.g., windows) at different virtual display levels (such as z-order levels). The rendering is based on the determination of a position and virtual display level for each of the visual items to be displayed. For those visual items that cast a shadow on lower-level in-shadow visual items, the determined position of the shadow-casting visual item is used to render the shadow on each of the in-shadow visual items differently depending on the corresponding virtual display level of the in-shadow visual items. In particular, the in-shadow visual item that has a lower virtual display level has a longer shadow cast by the shadow-casting visual item than those in-shadow visual items that have a higher virtual display level. This allows the shadows to have a more natural look.