What about mlpy, shark, mlpack, shogun, orange, elki, HLearn, etc.? There is very much the list doesn't cover (no offense to the list authors---just, there is a lot out there).
Also probabilistic programming stuff: PyMC, Stan, Dimple, Church. Not sure if these are 'lesser known', PyMC is mentioned often, still much less hype nowadays than neural networks.
Thanks for the suggestions. I don't think PyMC3 and Stan are less known, hence did not suggest to add them in the list.
Dimple and Church look good additions. Will get them appended.
