I'm spending some time learning Clojure and am so far, thoroughly enjoying it. Writing the code is a breeze in Emacs. Historically, Emacs has always been a top notch environment for writing Lisp code. Thanks to the swank-clojure module, writing Clojure in Emacs is just as easy as writing Common Lisp in Emacs. I think this is a great benefit to the Clojure community. One of the problems many languages face is the tool set early in the life of the language. Languages that come to mind are Haskell, OCaml, Ruby, Groovy, JavaFX and so on. Ruby, Groovy and JavaFX are coming along, but early on, it was a struggle. Clojure instead was able to lean on SLIME for that IDE-like support. SLIME has been around for quite a while and already had robust support for Lisp. Since Clojure could leverage this, it got most of the IDE stuff for free.