"Ducky" is a flexible and versatile software system for processing, rendering, and animating 3D datasets. The system is based on a powerful run-time interpreted language similar to C. The language includes many built-in functions for animation, rendering, shading, surface definition, and the creation of interactive menu and window-based visualization environments. Both volume and surface rendering methods are provided and may be combined in a single visualization. Ducky can create animations of a sequence of different views of a structure either within a 3D volume or across a series of volumes. Scripts implementing several common visualization tasks are provided. The system is readily extendible. Existing scripts can be modified or new scripts written to create additional interactive environments and processes.