I have nothing to say on Lein vs Boot, but I&#x27;m a long-term emacers with &gt; 10 years and I can&#x27;t endorse Cursive strongly enough. I&#x27;ve got easily at least 1k hours in my .emacs.d. Suffice it to say, it takes a lot to take away from Emacs&#x2F;SLIME. Never bought into the Textmate hype during the Ruby days, or the SublimeText hype subsequently because Emacs already had all that functionality if not out of the box, there certainly was someone with an .el I could borrow. It takes <i>a lot</i> for me to leave Emacs, <i>especially</i> for a LISP.<p>Here&#x27;s my 2 cents - <i>Cursive is worth it</i>. (Hey Ideogram folks, if you want an endorsement, feel free to use that paragraph in exchange for a lifetime license ;)). For one-off-scripts, for back-end solutions, and what tipped me over the edge, it&#x27;s CLJS script integration goes beyond acceptable -- it&#x27;s actually <i>fun</i> to work in-- Cursive is my go-to. Om and Figwheel (optionally with Prismatic Schema if you like type guarantees) makes web development&#x27;s feedback loop a lot tighter.<p>Rich Hickey assembled a team of just <i>insanely</i> talented and charismatic(1) developers who not only are a) remarkably intelligent but b) know when to steal ideas and integrate them [none of that too-proud-NIH-syndrome there], and c) know how to interact in a way to that is community-feedback-positive(2) so people contribute. Watch this talk by David Nolen <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=ByNs9TG30E8" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=ByNs9TG30E8</a> (CLJS lead). [Sidebar - He even mentions how that whole immutable, one way data flow, datomic-ish single state idea existed in other languages, but read (2) on that].<p>Anyways, Cursive + Lein + ClojureScript + Om is the holy grail for me right now. On the other hand, that nREPL&#x2F;cider&#x2F;boot setup is what I&#x27;d be using as a long-time emacs&#x27;er were I to give up Cursive.<p>(1) Having someone like Hickey or Nolen to shepherd ideas is actually really important in garnering traction. Developers go to conferences and when everyones talking about that 4PM Thursday talk that someone gave, it really resonates within the community for quite a while. I like Perl 6&#x27;s ideas but if you&#x27;ve ever seen Larry Wall talk, well, yeah. 
(2) Some communities <i>cough Haskell</i> have great ideas, Lenses, FRP, applying (pun not intended) monoids -&gt; functors -&gt; applicative functors -&gt; monads was genius. But for some reason the barrier to entry is so high (even for me with a fairly advanced math background) that concepts remain isolated within the community. LINQ is a monad (though few know it) and it took Brian Beckman (or Anders, or Bart de Smet, or whomever) to take it into C# to make the concept widely used by the Joe-the-programmer (again, pun not intended).