This is a testbed that I wrote for playing with the A* pathing algorithm. Currently, you can choose between two different open list sorting methods and try them a maze that you create by clicking in the grid. The number of comparisons are counted in the upper-left. You can change the zoom level and the speed of the updating with the sliders on the right.The application is written in Java, so you'll need at least version 1.4 of J2SE to run it.

Left click to set the start point.
Right click to raise the cost of a tile and drag it to copy that value to nearby tiles.
Shift+Right click to lower the cost of a tile.
Middle click to start the algorithm.



Download the compiled JAR file here.
Download the source code here.