Clojure is a dialect of lisp that is implemented on the Java Virtual Machine, so it is easy to install and run almost anywhere. The details can be found at http://clojure.org/. As this book is being prepared Clojure is rapidly becoming popular, as it is gaining recognition as perhaps the most practical implementation of an early high-level language that many consider to be the most powerful ever devised. Although Clojure is still in a somewhat early stage of adoption, it is quite mature, used in large projects and by big companies, and you can use gnuplot from it.
You need, naturally, an installation of the Clojure language. You may be able to install it using your package manager if you are using a Linux distribution (it is available in Ubuntu, for example); otherwise, you can download it from its official page at http://clojure.org/downloads. We are using the program clojure-gnuplot by Vadim Shender, so you should get that from https://bitbucket.org/vshender...
