"Clojure is a dynamic programming language that targets the Java Virtual Machine. It is designed to be a general-purpose language, combining the approachability and interactive development of a scripting language with an efficient and robust infrastructure for multithreaded programming. Clojure is a compiled language - it compiles directly to JVM bytecode, yet remains completely dynamic. Every feature supported by Clojure is supported at runtime. Clojure provides easy access to the Java frameworks, with optional type hints and type inference, to ensure that calls to Java can avoid reflection. "
» http://packages.ubuntu.com/en/karmic/clojure
With the recent release of Stuart Halloway's "Programming Clojure" by The Pragmatic Programmers, exposure for clojure will greatly increase. Backporting the package would only help :)
A package created by "prevu clojure/karmic" works fine on my Jaunty system.