&gt; I&#x27;m inclined to think the clojure repl is more conducive to experimenting.<p>I&#x27;m inclined to think the Clojure REPL is more conducive to <i>flailing around</i>. Now, this might sound like derision, but it isn&#x27;t intended that way: Flailing around can be a very time-efficient way to familiarize oneself with an unknown domain, especially if the cost of making wrong design decisions is small.<p>But at some point one has to <i>consolidate</i> what one already has, and, in my experience, Clojure makes this very difficult.<p>&gt; I guess one programmer&#x27;s sandbox is another programmer&#x27;s hellish nightmare of mutability.<p>If you absolutely want mutable definitions, you can have them in Haskell (with some noise) and ML (with no noise) too: <a href="http:&#x2F;&#x2F;pastebin.com&#x2F;00ScnFxC" rel="nofollow">http:&#x2F;&#x2F;pastebin.com&#x2F;00ScnFxC</a> . So a Haskell or ML programmer always has at their disposal whatever they think is the best tool for the job.<p>Can I have it the other way around in Clojure?