1. In a memory of a computer system, a multimedia application framework for creating a multimedia application which processes multimedia data in response to a request, the application framework comprising: a subclassable media component base class for deriving media component classes used to instantiate media component objects wherein the subclassable media component base class includes data defining an input port and data defining an output port; means responsive to the media component base class for instantiating a plurality of media component objects; means for connecting the plurality of media component objects into a topology of media component objects wherein the connecting means connects the input ports and the output ports of the plurality of media component objects; means, responsive to the multimedia data, for iterating through the topology to identify media component objects which am ready for execution and for placing the media component objects that are ready for execution on a run list wherein the means for iterating through the topology includes means for simulating data flow through the topology to identify media component objects which are ready for execution without requiring any of the plurality of media component objects to process media data; and means responsive to the request for executing the media component objects on the run list.