AlphaGo

AlphaGo is a computer program that plays the board game Go. It was made by DeepMind Technologies (Google affiliate). This program became famous due to the victories against professional players.
Many new technologies were used to create AlphaGo, including deep learning, optimization, and the Monte Carlo algorithm.
Powered versions.
After the release of AlphaGo, DeepMind Technologies has made powered versions such as the AlphaGo Zero and the AlphaZero: AlphaZero is a self-taught program. This means that it became powerful without human guidance.
Details.
The following table is the summary of AlphaGo achievements (including its variants).
Rivals.
After the appearance of AlphaGo, several research groups have created computer Go programs with similar technical viewpoints.
Darkforest.
This was made by Facebook. The source codes are available on GitHub.
DeepZenGo.
This was made in Japan. Nihon Ki-in was also involved in its research and development.