Introducing DL4J and ND4J

A lot of the libraries of deep learning have been developed all over the world. In November 2015, TensorFlow (http://www.tensorflow.org/), a machine learning/deep learning library developed by Google, became open to the public and attracted great attention.

When we look at the programming language with which libraries are being developed, most of them open to the public are developed by Python or use the Python API. TensorFlow is developed with C++ on the backend but it's also possible to write code with Python. This book focuses on Java to learn deep learning, hence the libraries developed by other languages will be briefly introduced in Chapter 7, Other Important Deep Learning Libraries.

So, what Java-based libraries do we have? Actually, there are a few cases that are actively developed (perhaps there are also some projects not open to public). However, there is only one library we can use practically: Deeplearning4j (DL4J). The official project page URL is http...