A system and method is disclosed for establishing an interactive multimedia application environment in which server-side streaming media may be controlled by a client using a programming model provided at both a communication server and an interactive multimedia runtime on the client. The application program interface (API) preferably provides methods for the client user to establish a stream of data from the client to the communication server in addition to allowing a stream from the communication server to the client. The API also preferably allows the user at a client to exert control over the broadcasting of the media streams. Streams may be built, edited, paused, stopped, augmented, and the like by the client user. Each function that the client user may operate on the broadcast media stream is preferably viewable by all of the other subscribing clients.