objects and interfaces:

Name: Rygel.MediaServer
description: The main object that talks to the control-points.

Name: Rygel.MediaProvider
description: Interface that all Media provider/backend objects must implement.

Name: Rygel.MediaDB
description: Object that:
        - imlements RygelMediaProvider
        - manages plugins that provides RygelMediaProvider

Name: Rygel.MediaTracker
description: tracker-based Rygel.MediaProvider implementation.
             http://www.tracker-project.org

Name: Rygel.MetadataExtractor
description: Helper object providing metadata extraction facility.