E4X: JavaScript for XML – The JavaScript Weblog – javascript.weblogsinc.com: A Javascript implementation for XML. The main article is written by John Udell and he mentions that the code in his article is written for Rhino which is Mozilla’s Java based Javascript interpreter. This technology is very cool and has a lot of possibilities, both incredibly useful and sinister. I can think of a bunch of exploits that could be very harmful, but I have not looked at the code in-depth.