1. A graphical display animation system supporting timed modification of element property values, the graphical display animation system comprising: a display structure for maintaining a set of elements, wherein an element includes a variable property value affecting a display characteristic of the element; a property system for maintaining properties associated with elements maintained by the display structure, including dynamic properties that are capable of changing over time; and animation classes, from which animation objects are instantiated, wherein the animation object instances provide time varying values affecting values assigned to the dynamic properties.