UCI

The Universal Chess Interface is an open communication protocol to allow chess engines to talk to each other or user interfaces.

Example:

stockfish
Stockfish 240314 SSE4.2 by Tord Romstad, Marco Costalba and Joona Kiiski
go 
info depth 1 seldepth 1 score cp 75 nodes 27 nps 13500 time 2 multipv 1 pv e2e4
info depth 2 seldepth 2 score cp 12 nodes 140 nps 70000 time 2 multipv 1 pv e2e4 e7e5
info depth 3 seldepth 3 score cp 51 nodes 345 nps 115000 time 3 multipv 1 pv e2e4 d7d5 b1c3 d5e4 c3e4
info depth 4 seldepth 4 score cp 12 nodes 1059 nps 211800 time 5 multipv 1 pv g1f3 d7d5 d2d4 g8f6
info depth 5 seldepth 5 score cp 50 nodes 1678 nps 279666 time 6 multipv 1 pv g1f3 d7d5 d2d4 g8f6 b1c3
info depth 6 seldepth 6 score cp 12 nodes 3941 nps 394100 time 10 multipv 1 pv d2d4 g8f6 b1c3 d7d5 g1f3 b8c6
info depth 7 seldepth 7 score cp 46 nodes 5356 nps 446333 time 12 multipv 1 pv d2d4 g8f6 b1c3 d7d5 g1f3 e7e6 e2e3
info nodes 5356 time 12
bestmove d2d4 ponder g8f6
quit