title: Fastest cross-platform A* implementation?
body: <p>With so many implementations available, what is the fastest executing (least CPU intensive, smallest binary), cross-platform (Linux, Mac, Windows, iPhone) A* implementation for C++ using a small grid?</p>
  
  <p><strong>Implementations</strong></p>
  
  <p>Google returns:</p>
  
  <ul>
  <li><a href="http://www.heyes-jones.com/astar.html" rel="nofollow noreferrer">http://www.heyes-jones.com/astar.html</a> (Most links on that site are dead.)</li>
  <li><a href="http://www.grinninglizard.com/MicroPather" rel="nofollow noreferrer">http://www.grinninglizard.com/MicroPather</a> (Said to be slower than Heyes-Jones'.)</li>
  <li><a href="http://www.ceng.metu.edu.tr/~cuneyt/codes.html" rel="nofollow noreferrer">http://www.ceng.metu.edu.tr/~cuneyt/codes.html</a> (Generic C++ code.)</li>
  <li><a href="http://swampthingtom.blogspot.com/2007/07/pathfinding-sample-using.html" rel="nofollow noreferrer">http://swampthingtom.blogspot.com/2007/07/pathfinding-sample-using.html</a></li>
  <li><a href="http://opensteer.sourceforge.net/" rel="nofollow noreferrer">http://opensteer.sourceforge.net/</a> (Interesting for games, not A*.)</li>
  <li><a href="https://stackoverflow.com/questions/938338/what-is-the-fastest-dijkstra-implementation-you-know-in-c">Stack Overflow on Dijkstra's Algorithm</a></li>
  </ul>
  
  <p>Any others?</p>
  
  <p><strong>The Wheel</strong></p>
  
  <p>The question, as asked, pertains to reuse (plug into a game), not reinvention (at least not until performance is shown to be an issue). It might turn out that a Dijkstra implementation (or generic pathfinding algorithm) is better suited, or that the fastest implementations are not fast enough. I appreciate the suggestions of alternative algorithms, however the question is not, "Should I roll my own A*?"</p>
  
  <ul>
  <li><a href="http://www.joelonsoftware.com/articles/fog0000000007.html" rel="nofollow noreferrer">Joel on Software - Not Invented Here Syndrome</a></li>
  <li><a href="http://www.codinghorror.com/blog/archives/001145.html" rel="nofollow noreferrer">Coding Horror: Don't Reinvent the Wheel</a></li>
  <li><a href="http://www.developer.com/open/article.php/3338791/Overcoming-Not-Invented-Here-Syndrome.htm" rel="nofollow noreferrer">Overcoming the "Not Invented Here Syndrome"</a></li>
  </ul>