pypy

pypy is a fast, compliant alternative implementation of Python, and also a toolkit for creating dynamic language interpreters.

Reference

Fast Enough VMs in Fast Enough Time , Laurence Tratt, 2012-02-08, 2012-02-07
PyPy's Approach to Implementing Dynamic Languages Using a Tracing JIT Compiler , Carl Fridrich Bolz , 2011-01-31
Writing an Interpreter with PyPy, Part 1 , Andrew Brown

Language Implementations

A Javascript Interpreter in RPython , stephan Zalewski
Converge
a dynamically-typed object-oriented programming language with compile-time metaprogramming facilities. Put simply, Converge has a macro-like facility that can embed domain specific languages with arbitrary syntaxes into source files.
Oyster
Lisp
pypy
Python
Pyrolog
Prolog
Spy
Smalltalk/Squeak
Topaz
Ruby

Description

pypy provides the ability to run untrusted code in a fully secure way. It also supports stackless mode, providing micro-threads for massive concurrency.

pypy interpreters are written in Rpython