An ActionScript 3 port of Mozilla's Rhino JavaScript interpreter


#1

How cool.


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#2

You have also Narcissus

in short a JS interpreter written in JS, which can be ported to AS3 too.

And in the same vein you can find Bringing the Browser to the Server (or project env.js) which can also be ported to AS3.
sources: https://github.com/jeresig/env-js