I was at Clojure Conj last October and in a room of 200 or 300 Clojure programmers, it looked like probably 70% of everyone had a MBP running usually OS X, some

I was at Clojure Conj last October and in a room of 200 or 300 Clojure programmers, it looked like probably 70% of everyone had a MBP running usually OS X, sometimes Ubuntu, and the other 30% (myself included -- although I dual-boot Windows) were running Linux on a PC laptop. I would be surprised if more than 10 people were running Windows as a primary OS. However, it's worth noting that the average age of the crowd there was almost definitely above 25.