This paper shows results of the operation of the rule-based system of a shape grammar interpreter interactive system, in development. The results are presented in the visual context of the system in terms of “grammar execution” of shape grammar example cases. In each case, the rules and initial shape of a shape grammar are presented, applicable rules are applied and design shapes produced by the interpreter are shown. Rules can be applied in the system by selecting one rule and triggering its application to a selected shape, either once at a time, or applying rules in a limited depth-first or breadth-first way or eventually mixing these two strategies. The hierarchy of the shapes produced at any time can be visualized in tree-like views.