Here is an universal parser in javascript: http://synth.wink.ws/moonyparser/

I've been to hell and back to make it faster, but that's it, shift-reduce can't be much faster. Unfortunately, finding errors in text makes it three times slower. At least it has linear parsing time.

That's someone's spam, sorry about that. However, if you're interested in a new version of Moony Parser with Earley algorithm implementation, check the real link: parser.moonyweb.com