No, you just need to be willing to learn some java APIs (honestly though, not that hard. mostly they are larger, more long-winded versions of things you are use

No, you just need to be willing to learn some java APIs (honestly though, not that hard. mostly they are larger, more long-winded versions of things you are used to in python). In particular for web stuff you could probably exist within the clojure eco system. The clojure-contribs package is getting pretty comprehensive these days. Clojure's interop stuff makes calling java seem fairly native. Obviously you get stateful behavior and need to be careful, but thats no worse than python or c. Currently clojure's tools for creating classes is a little frustrating but thats being replaced with some very nice facilities in 1.1. I'd say the number one thing you'll need to do is get familiar with the javadoc. For the reference, i programmed java at uni (2001-2004) with Java 1.4. I havent written a java program since then, but i havent found it any hinderance at all in my experiments with clojure.