Clasp
Clasp is a Common Lisp implementation that interoperates with C++ and uses LLVM for just-in-time (JIT) compilation to native code. See announcing clasp for the initial announcement.

If you would like to try out Clasp, there are binary packages for downloading, and if you are running Arch Linux, there is an AUR package available for building from source.

Also see the following in case you would like to follow Clasp's development:


Common Lisp implementation