1. A system comprising: one or more modules implemented at least partially in hardware, the one or more modules configured to implement a single composition engine that is configured for: accessibility by a plurality of processes via one or more application programming interfaces to render elements for display on a display device; and managing sharing of a shared compositional resource by the plurality of processes, the shared compositional resource involved in the rendering of the elements, wherein the shared compositional resource follows a reader/writer paradigm managed by the single composition engine for access by the plurality of processes such that a reader process is configured to specify what element is displayed and a writer process is configured to create the shared compositional resource and to specify how the specified element is displayed, the writer process lacks permission to specify the element, the reader process lacks permission to specify how the specified element is displayed, the reader and writer processes included in the plurality of processes.