CHIRON CHESS ENGINE:
http://www.chironchess.com/


STOCKFISH CHESS ENGINE:
https://stockfishchess.org/

KOMODO CHESS ENGINE:
https://komodochess.com/

HOUDINI CHESS ENGINE:
http://www.cruxis.com/chess/houdini.htm

TCEC:
http://tcec.chessdom.com/archive.php