http://stockfishchess.orgthat should be the 3. strongest chessengie in the world and its not commercial - it´s open souce.
they do daily tests 24/7 to improve the alghoritm and the engine will be stronger and stronger.
the engine can used on most popular GUI like arena3, fritz ......
to participate in the testing part we could be a help to build the best engine because they need computing power to improve the code.
every test has a new build stockfish.exe. base.exe is the old one. they play together.. the more stockingfish is winning the better it is.
the developers needs our help because the need computing power to test if the code is better or not.
then we play games again and see what happens. is it better is it ok and other changes can made and other parameters can tested.
at the moment the development is good but they need POWER to test the changes every day and world ranking is 3th place.
but they want to be the best and it´s open source.
every body can participate and/or develop.
Norman