On top of Theano (Bergstra et al., 2010) , THUMT implements the standard attention-based encoder-decoder framework for NMT<cite> (Bahdanau et al., 2015)</cite> . It sup- * Corresponding author: Yang Liu. ports three training criteria: maximum likelihood estimation<cite> (Bahdanau et al., 2015)</cite> , minimum risk training , and semisupervised training .