ClojureScript is a robust, practical, and fast programming language with a set of useful features that together form a simple, coherent, and powerful tool.

ClojureScript is a compiler for Clojure that targets JavaScript. It emits JavaScript code which is compatible with the advanced compilation mode of the Google Closure optimizing compiler.

Why Clojure?

Clojure is a dynamic, general-purpose programming language supporting interactive development. Clojure is a functional programming language featuring a rich set of immutable, persistent data structures. As a dialect of Lisp, it has a code-as-data philosophy and a powerful macro system.

Why JavaScript?

The spread of the browser and web-based applications has given JavaScript an exclusive reach unmatched by any other language. Because of its importance, JavaScript engines are also receiving extensive research and optimization allowing JavaScript to compete for performance with many more established platforms like the JVM.

Why Google Closure?

As the purveyors of some of the most complicated client-service web applications in use today, Google has invested heavily in creating the Closure library and Closure compiler which work together to make whole program optimization possible, yielding programs that provide minimal load times even when using many libraries.


ClojureScript combines the reach of the JavaScript platform, the flexibility and interactive development of Clojure, and the whole-program optimization of Google Closure to provide the most powerful language for programming the web.

Companies Succeeding with ClojureScript

“Learning to use ClojureScript, Om, and React finally made me feel like I was taking ownership of my design work from beginning to end.”
Danny King, Co-Founder/Designer
“[We designed our software] with just immutable data structures and pure functions (with much less code than traditional OO languages) allowing us to focus on our core business requirements rather than inherent technological problems.”
Asier Galdos, Co-founder/developer
“Clojure and Clojurescript are the backbone of our business.”

“Clojurescript offers a language and environment that is far superior (and less error-prone) than plain-ol' Javascript, even with frameworks.“

State of Clojure 2015 survey


Cognitect is a collection of experienced, thoughtful technologists, passionate about helping organizations deploy technology effectively and humanely to build better futures.

In addition to working directly with companies to deliver innovative solutions, Cognitect offers architectural review, training and talent development services for companies and teams deploying Clojure and ClojureScript.

Cognitect are also the makers of Datomic, a transactional database with a flexible data model, elastic scaling, and rich queries. Datomic Ions let you develop Clojure applications for AWS by deploying your code to a running Datomic cluster.

“We have created some of the sharpest tools in the business. We believe this platform is a better way to develop software, and we want you to have confidence using and deploying these tools. Open source doesn't mean you're on your own any more.” –