A set of buffers is made available on a system-wide basis to provide capabilities for robust presentation of windows. The buffers can include a frame buffer, a system off-screen buffer and a compositing buffer.Windows are analyzed to determine and implement the most time-and memory-efficient use of the available buffers to properly display the intended result. In some situations, applications write directly to the frame buffer. Clipping can be used to prevent occluded portions of windows from being displayed. In other situations, some data is written to the off-screen buffer and/or to one or more application buffers, and the compositing buffer is used to perform compositing operations.Thus, a device can provide a wide range of display capabilities, including window compositing, while minimizing costs in terms of memory usage and processing power. Such advantages are of particular use in mobile devices and other systems having limited resources.