Clojure was initially implemented on cl. You should be able to find the lisp version in the history of the repo somewhere. Might be an interesting starting point.
Rich originally made two other JVM/lisp hybrids, one was running java code inside CL, the other was CL on the JVM. [1]
Clojure originally targeted the JVM and CLR, but AFAIK, one of the main motivators was always to run on a major platform.
One was a Lisp(Works) FFI to Java (jfli) and the other was a generalized version of that (foil).
I have seen too the early sketch of Clojure in CL.
Look here: http://clojure.googlecode.com/svn-history/r454/trunk/src/lis...
I didn't realize there was a CL version of the compiler, cool! Thanks for the link.
Really? I thought Clojure evolved out of Rich's never-finished CL-subset-on-JVM implementation.