rdr is my very first completely generative movie. The abbreviation rdr stands for the somewhat awkward name "reaction diffusion rectangles". The generator of rdr is a small java program which combines a reaction diffusion simulation with rectangle drawing and audio blip producing routines. The virtual chemicals in the reaction diffusion simulation, their concentrations and positions control the width, height and position of graphical rectangles. The mapping from the reaction diffusion simulation into rectangle space can be interactively modified by the user. The sound part interprets the rectangle drawing as a sort of sequencer in which each vertical line corresponds to a time position for a small sound burst.