The OpenJIT project is an ongoing Java[tm] the programming language JIT
compiler project as a collaborative effort between Tokyo Institute of
Technology and Fujitsu Laboratory, partly sponsored by the Information
Promotion Agency of Japan.

OpenJIT is a "reflective" JIT compiler in that not only it is almost
entirely written in Java, but also that it bootstraps and compiles
itself during execution of the user program, and compiler components
coexist as first-class objects in user heap space.