Do all browsers support PHP's $_SERVER['HTTP_X_REQUESTED_WITH']?

Question

Do all browsers support PHP's $_SERVER['HTTP_X_REQUESTED_WITH']?

Do you know of any browsers or times where $_SERVER['HTTP_X_REQUESTED_WITH'] would not work?

Answer 1

Sending of a X-Requested-With header really depends on the Ajax library used. I checked out Prototype, jQuery, Mootools and YUI and they all set it.