Neural machine Translation
Statistical Machine Translation
While the vast majority of statistical machine translation systems maintain an alignment of source and target words (or word groups), some work explored machine translation without such alignment.
MT Without Word Alignment is the main subject of 5 publications. 4 are discussed here.
Topics in WordBasedModelsIBM Models | Symmetrization | Word Alignment | Dictionaries From Comparable Corpora | Lexical Choice | MT Without Word Alignment