Any chance you could add JEE6? The two major JSF 2.1 implementations MyFaces and Mojarra are both missing. I don't expect awesome performance numbers, but since JSF2.1 is the 'official' (sigh) web framework of JEE6, it would be interesting how awful they are compared to some of these other languages.

I guess though if this is only testing JSON serialization, it may not make sense. Perhaps adding JAX-RS implementations like CXF, Jersey, RESTEasy, and RESTLet would be more appropriate.