Core War is a programming game (see: http://en.wikipedia.org/wiki/Core_War).
This is a javascript implementation of the engine (and hopefully soon some visuals).
Parsing Redcode is actually pretty complex, so I wrapped the parser from pMARS (the Core War standard) to provide a binding for Node.
The eventual goal of this project is to provide a website arena to host battles.
Because I have the pMARS code in here I think this ends up being GPL also.