POX or Plain Old XML is a term used to describe basic XML, in contrast to more complicated XML specifications like RDF, much in the same way POJO contrasts to EJBs.
"Piggly Wiggly Carolina Co. has cut costs by 70% since going from a VAN to AS2 with 200 of its 600 trading partners, according to Kathy Davis, a lead systems analyst at the Charleston-based grocer."