Deeplearning4j (DL4J) is an open-source, distributed deep-learning project that can serve as a DIY tool for Java, Scala and Clojure programmers working on Hadoop and other file systems. DL4J is designed to be used in business environments on distributed GPUs and CPUs. DL4J can import neural net models from most major frameworks via Keras, including TensorFlow, Caffe, Torch and Theano, bridging the gap between the Python ecosystem and the JVM with a cross-team toolkit for data scientists, data engineers and DevOps.