In computer-participative multimedia applications, the com- puter not only manipulates media, but also digests it and performs independent actions based on media content. We present a design approach that applies the programming techniques of visualization systems to the development of computer-participative multimedia applications. We de- scribe an implementation based on this approach, and report performance measurements that demonstrate it is practical. We conclude by describing three applications written with the system, and suggest future directions for research in the area.