The classification according to attractor type is from W. Li and N. Packard, "The Structure of the Elementary Cellular Automata Rule Space," Complex Systems, 4
(3), 1990 pp.
281-297. The classes are (1) null point, (2) homogenous, (3) periodic, (4)
locally periodic, and (5) globally chaotic. There are 88 rules, reduced from the 256 elementary rules under the left-to-right transformation, the 0 to 1 transformation, or a combination. In its default setting, the Demonstration highlights new black cells and new white cells only. Different color settings can reveal the unhighlighted, perturbed evolution or the changes superimposed on the unaffected cells.