OpenJDK Port of VMKit
Overview
VMKit [1] is a VM substrate built on LLVM with functional Java VM and has been used for CLI, Python, and R. For improved compatibility and to learn the inner workings of a language runtime, I ported VMKit to optionally be built with OpenJDK instead of GNU Classpath.
Status
Many things work (eclipse, most of dacapo 2009), but there are still missing pieces of functionality such as global weak references.
Luckily, it seems the VMKit project has been revived (2012) in the form of VMKit2 [2] which hopefully further improves OpenJDK support.