Parrot VM

From AJS.COM

The Parrot VM is a virtual machine that was origianlly designed to be the basis for the Perl 6 programming language, but is now aimed more generically at supporting any high-level, dynamic programming language .

Features

Parrot features of note:

High level byte-code allows system-specific optimization of very abstract code
Just-in-time compilation for high performance
Support for most lexical and dynamic scoping modes
Support for a wide range of function calling conventions
Closures and continuations directly supported
Abstract typing system available to support just about any typing / object system
Multi-method dispatch
Multi-threading
Abstract exception system allows pluggable language semantics