1. An XML printer system adapted for printing bar code labels, tags, tickets, cards or other media and/or for encoding of RFID devices associated with a media, based upon an extensible markup language (XML) input data stream, the XML printer system comprising: a computer system having a memory subsystem; a communication interface; an XML processor configured to receive the XML input data stream; a formatting engine configured to format XML data in the XML input data stream according to a format governed by a format template; and a rendering engine configured to receive the formatted XML data and generate a printable presentation of the bar code label, tag, ticket, card or other media and/or generate encoding information for the RFID device.