AI EXP was originally a personal blog of Kai Sun, established in 2011. Although mixed-genre contents were posted here, most of them were about board game AIs, and particularly the website has witnessed the development of Yixin, a world champion gomoku and renju program designed by Kai. As Kai has achieved his primary goal in this area, the development of Yixin has been stopped (indefinitely) after Yixin finished its match with human world champions in both gomoku (2017) and renju (2018). Now, AI EXP serves as an archival collection of information about Yixin.