DL4J or Deeplearning4J is an open source deep learning library which is targeted at Java/Scala. It can be directly used for deep learning implementations by non-researchers in an easier manner compared to Theano. It allows the development of faster prototyping, and is available under the Apache 2.0 licence. The DL4J use cases are listed below: Image recognition Speech processing Spam filtering E-commerce fraud detection, etc The important features of DL4J are: GPU integration Robust n-dimensional array handling Hadoop and Spark scalability ND4J, which is a linear algebra library, and runs 200 per cent faster than Numpy Canova, which is a vectorisation tool for machine learning libraries. The neural network architectures supported by DL4J are shown in Figure 6.