Not sure exactly how this maps to Common Lisp, but it looks like JDK 9 will have a lot of interesting new APIs for compiling efficient code for langauges other than Lisp. The latest I have found out about is [JEP 276: Dynamic Linking of Language-Defined Object Models][1]. [1]: http://openjdk.java.net/jeps/276 -- "A screaming comes across the sky. It has happened before, but there is nothing to compare to it now."