I developed these Flash applets in 2008 to add some interaction to my A* pages (background), but wasn't quite happy with the visualization. They match the style used on my existing pages but I think that style, although colorful, misses the important notion of an expanding fringe. At some point I'll make a version I'm happy with. Until then, free to play with these incomplete applets, or browse the source code:
Drag the blue/red circles around to change the start/end points. Drag or click anywhere else to toggle whether a square is passable.