Systems and techniques by which content and presentation players can communicate are described. In one aspect, presentation system for rendering a presentation for a user includes one or more output devices, a presentation including machine-readable descriptions of content and a service request triggering mechanism to trigger a service request, and a presentation player configured to generate a rendition of the presentation at one or more output devices and to respond to the service request with a service response to populate the rendition of the presentation. The service response includes at least one of information characterizing an arrangement of content in the presentation and information characterizing prior navigation of the user through the content of the presentation. The presentation further includes extraction logic to extract relevant information from a response to the service request for addition to the rendition of the presentation.