Preface

To fully appreciate Clojure, we hearken back to Paul Graham’s essay “Beating the Averages,” an interesting look at the inner workings of his company Viaweb during the years prior to being bought by Yahoo! Inc. in 1998. Though interesting as survey of startup culture, the truly memorable part of the essay was the description of how Viaweb used the programming language Lisp as an advantage over its competition. How could a programming language more than 50 years old provide any market advantage over Viaweb’s competitors, who were surely using modern enterprise technologies? Without repeating the exact terms of the essay, Graham makes a compelling case for the capability of Lisp to facilitate a more agile programming environment.

Clojure is a dialect of Lisp directly supporting concurrent software development using functional programming techniques, and like the Lisp described in “Beating the Averages,” provides an environment conducive to agility. Clojure fosters agility in ways that many popular programming languages can’t. Many programming languages are bewitched with most or all of the following: