Rather funny that binary XML is needed by people. A couple of standards I had come across (DVB-H and T-DMB service metadata) would like to have XML ‘encoded’ in some kinda binary format. The T-DMB people have a binary encoding (pdf) with single byte tags corresponding to a set of XML elements. I’ve always felt the same way as many who think Binary XML is an oxymoron. Let me see if the stuff at w3c can change my mind.