One of the pieces of software required for this book is the Java Development Kit (JDK), which you can get from http://www.oracle.com/technetwork/java/javase/downloads/. JDK is necessary to run and develop applications on the Java platform.

The other major software that you'll need is Leiningen, which you can download and install from http://github.com/technomancy/leiningen. Leiningen is a tool for managing Clojure projects and their dependencies. We will explain how to work with Leiningen in Chapter 1, Working with Matrices.

Throughout this book, we'll use a number of other Clojure and Java libraries, including Clojure itself. Leiningen will take care of the downloading of these libraries for us as required. You'll also need a text editor or an integrated development environment (IDE). If you already have a text editor that you like, you can probably use it. Navigate to http://dev.clojure.org/display/doc/Getting+Started to check the tips and plugins required for using your particular favorite environment. If you don't have a preference, I suggest that you look at using Eclipse with Counterclockwise. There are instructions for getting this set up at http://dev.clojure.org/display/doc/Getting+Started+with+Eclipse+and+Counterclockwise.

In Chapter 9, Large-scale Machine Learning, we also use MongoDB, which can be downloaded and installed from http://www.mongodb.org/.