There have been a large number of Deep Learning Libraries that have been released recently.<p>TensorFlow is getting a lot of buzz.  Theano and Torch are often spoken about.  Berkeley has Caffe and Microsoft has released CNTK.  Nvidia has cuDNN and Keras looks very nice.  What have you used?  What do you like about the library?  What are your pain points?
Ask HN: What Deep Learning Libraries are you using?