Yes, XML has the same problem. The end of that paragraph reads: > The same problems occurred in XML (and CORBA), and though JSON is an improvement in that it a

Yes, XML has the same problem. The end of that paragraph reads: > The same problems occurred in XML (and CORBA), and though JSON is an improvement in that it allows fields to be added more easily, the tooling to support conversion/evolution hasn't grown up around it (and isn't growing). Maybe it's not clear, but the tooling to solve these problems has grown up around XML. Mainly XSLT, and visual mappers that operate on top of that. Examples: MS's Biztalk mapper http://msdn.microsoft.com/en-us/library/aa547076.aspx http://msdn.microsoft.com/en-us/library/aa547076.aspx; MapForce http://www.altova.com/mapforce.html http://www.altova.com/mapforce.html; StylusStudio XML mapper http://www.stylusstudio.com/xml_to_xml_mapper.html http://www.stylusstudio.com/xml_to_xml_mapper.html; both IBM and Oracle have similar - this category of tooling has been around a decade or so; XSLT itself started in 1997 http://en.wikipedia.org/wiki/XSLT http://en.wikipedia.org/wiki/XSLT). Have a look at the images in those links - you'll immediately see what they do. So to be precise, XML doesn't solve these problems, its tools do.