Clojure

OK. Consider me won over.
Lisp is great to work with. The things that grabbed me about FP in Erlang and Haskell (pattern-matching arguments, partial application, lazy evaluation) are all here.
My code is as concise as Erlang and damned nearly as concise as Haskell (I think the line count is similar though the number of characters per line is about twice as high)
Although I respect Haskell’s type system, Clojure’s dynamic typing holds me up less. I *am*, admittedly, hitting more problems that a type system would have picked up. (Far more than I typically hit in Python) but I think as I get more used to the language this will go down.
I’m not being particularly demanding in terms of libraries. (Quil is almost all the libraries I need at the moment.) But I’m finding that there are all these handy things like spit which make me smile. (Remember what this was like in Java?)
Things that would still be a bit fiddly in Python / CoffeeScript continue to turn out to be easier than I imagined they would be when I implement them in Lisp. That’s partly because I default to approaching them as “how do I write a small lambda that can then map across this list” and mostly, by the time I wrote that function, all I have to do is … er … map it across the list.
Lisp is extra-ordinarily compressible. I keep finding ways to refactor and fold up things I did earlier to make them shorter and shorter. And the more functionality I add to my program the more compressed it seems to get.
I am grinning to myself at the thought that my code might be compilable to both Android and into Javascript. I haven’t tried either yet, but if I manage it then Clojure is now my new favourite language.
CoffeeScript isn’t at all bad, but if ClojureScript works out, then I’ll probably start to move aggressively to use it as my default in-browser language. (And yes, I guess that may mean rewriting OWL in it. OWL is still short enough that I think I could sprint it in a couple of days.)
Similarly, if I can compile Clojure libraries that can be called from Java projects then you’ll start to see me more productive on Android. (Beyond OWLdroid I have a couple of other bits and pieces of apps. written, but not taken them to completion. If Clojure slots painlessly into the workflow, it will be a lot more tempting to dive back in.)
So … yeah … Clojure rocks!