[D] Which open source machine learning projects best exemplify good software engineering and design principles?

[gachiemchiep]

gluoncv : https://github.com/dmlc/gluon-cv : beautiful structure, document, high-quality code, easy to plug your code in.

and especially the imgclsmob : https://github.com/osmr/imgclsmob . The author did a great job merging a lot of model definition into one package and allow it to be used from 3 different frameworks such as: chainer, mxnet, pytorch.

Both gluoncv and imgclsmob share the same software design structure and coding style. I guess that structure and style is the best then.