Kawa supports TCO with an optional flag. It uses trampolines to work around the JVM's limitations. This makes Kawa more akin to a real Scheme. (Still doesn't have full conts, only upward conts which are homeomorphic to Java exceptions.)

Clojure could have done the same, but Rich Hickey deliberately chose not to, instead providing a special 'rec' construct for tail self calls. But this doesn't make Clojure not a Lisp, it only makes it not a Scheme.