PyPy
PyPy is a Python implementation in Python. Yes, it can interpret itself!
Please refer to [http://codespeak.net/pypy the PyPy home page] for more information about this upcoming Python implementation.
PyPy 1.0 was released on 27/03/2007 http://codespeak.net/pypy/dist/pypy/doc/release-1.0.0.html
It includes a JIT compiler, stackless-like functionality, uses the [http://www.hpl.hp.com/personal/Hans_Boehm/gc/ Boehm garbage collector] and has whole lot of "backends" - C, LLVM, JavaScript, CLI, Java.