The document summarizes the OpenWF Composition 1.0 API for compositing 2D graphics. It describes key concepts like devices, contexts, sources, elements and rendering. A device represents graphics hardware. A context defines a visual scene for on/off-screen targets. Sources and elements contain image data that is composited onto the context according to attributes like transparency type and scale filtering. The API provides functions for device/context/element management and rendering frames with composition.