Considering XMLHttpRequest is what other browsers used before IE caught up, I assume it does work the way you'd expect across modern browsers. I'd have to check the standard and IE8+'s conformance to the standard to be sure. That's what this post is really about for me, reminding that modern browsers follow a standard that allows for getting rid of most of jQuery. Reading it also made me recall a post from 2005 by PHP's creator: http://rajshekhar.net/blog/archives/85-Rasmus-30-second-AJAX... (Note IE uses ActiveXObject.)