Hjalmar Munsterhjelm - Koivikko ja ruispelto 
an UCI compliant open source chess engine by Finn Eggers and Kim Kåhre, written in C++, and first released on GitHub in September 2020 under the GPL v3.0. The bitboard engine provides automated evaluation tuning by logistic regression, either using stochastic gradient descent or AdaGrad. However, the current perceptron approach of the evaluation may soon be replaced by an own NNUE  .
v1.0 & v2.0