We introduced ROBO, a flexible Bayesian optimization framework in python. For standard GP-based
blackbox optimization, its performance is on par with Spearmint while using the permissive BSD
license. Most importantly, to the best of our knowledge, ROBO is the first BO package that includes
Bayesian neural network models and that implements specialized BO methods that go beyond the
blackbox paradigm to allow orders of magnitude speedup.

Snoek 2012 paper
code here: http://www.cs.toronto.edu/˜jasper/software.html
TPA: https://github.com/jaberg/hyperopt/wiki

DeepMind's paper on bayesian optimization

overview of bayesian optimization by the author of Spearmint