An implementation of a recent algorithm (Vüge, Jurdzinski, to appear in CAV 2000) for the construction of winning strategies in infinite games is presented. The games under consideration are “finite-state parity games”, i.e. games over finite graphs where the winning condition is inherited from ω-automata with parity acceptance. The emphasis of the paper is the development of a user interface which supports the researcher in case studies for algorithms of ω-automata theory. Examples of such case studies are provided which might help in evaluating the (so far open) asymptotic runtime of the presented algorithm.