I just discovered this ruby: https://github.com/gfwilliams/tiny-js
I've been looking quite some time for this, since spidermonkey/v8 usually is pretty big and comes with several dependancies. Tiny-js is a portable 'run make and your done'-linux c-class. Perfectly for if you are only looking for simple bindings and prefer javascript/c-syntax over lua/other awesome scriptinglanguages.