Clojure in your browser
12 Nov 2025There is a recent article on Clojure Civitas on using Scittle for browser native slides. Scittle is a Clojure interpreter that runs in the browser. It even defines a script tag that let’s you embed Clojure code in your HTML code. Here is an example evaluating the content of an HTML textarea:
HTML code
<script src="https://cdn.jsdelivr.net/npm/scittle@0.6.22/dist/scittle.js"></script>
<script type="application/x-scittle">
(defn run []
(let [code (.-value (js/document.getElementById "code"))
output-elem (js/document.getElementById "output")]
(try
(let [result (js/scittle.core.eval_string code)]
(set! (.-textContent output-elem) (str result)))
(catch :default e
(set! (.-textContent output-elem)
(str "Error: " (.-message e)))))))
(set! (.-run js/window) run)
</script>
<textarea id="code" rows="20" style="width:100%;">
(defn primes [i p]
(if (some #(zero? (mod i %)) p)
(recur (inc i) p)
(cons i (lazy-seq (primes (inc i) (conj p i))))))
(take 100 (primes 2 []))
</textarea>
<br />
<button id="run-button" onclick="run()">Run</button>
<pre id="output"></pre>Scittle in your browser