Recommendation: Has Potential.
Description: From a choice of two graphs, user sees an animation showing queue-based topological sort. That is, the algorithm first counts the in-degree of each node, then starts pulling off and processing 0-degree nodes. User can select random graphs from one of two sizes.
Evaluation: Can view this as a straight animation (not recommended) or by steps. Unfortunately, it is a little tricky to figure out how to get it into step mode. No explanation of the process is given, so it is hard to tell what is going on.