Armed Bear
The right of the people to keep and arm bears shall not be infringed!

Armed Bear Common Lisp (ABCL) is an implementation of ANSI Common Lisp that runs
in a Java virtual machine. It provides a runtime system, a compiler that
compiles Lisp source to JVM bytecode, and an interactive REPL for program
development.

ABCL runs on platforms that support Java 1.4 (or later), including Linux,
Windows, and Mac OS X.

WWW: http://armedbear.org/