Abstract: A computing device outputs an arrangement of a set of windows organized into one or more visual stacks. Each respective visual stack from the one or more visual stacks comprises a respective subset of the set of windows sequenced based on a characteristic. The computing device determines that a first window from the set of windows has a particular relationship with a second window from the set of windows, wherein the particular relationship is not based on the characteristic. The computing device outputs, responsive to the determining, a visual indication of the first window that visually differentiates the first window from windows from the set of windows not having the particular relationship with the second window.