Keras - Keras is a minimalist, modular neural networks library, written in Python and capable of running on top of either TensorFlow or Theano.
Machine Learning Playground - Breathtaking visuals for learning ML techniques.
Knet - Knet is a deep learning framework that supports GPU operation and automatic differentiation using dynamic computational graphs for models.
Amazon Machine Learning - Machine learning made easy for developers of any skill level
Microsoft Cognitive Toolkit (Formerly CNTK) - Machine Learning
Lobe - Visual tool for building custom deep learning models