XML is simply a file type readable by XPression. XML by itself is a way of encoding data that is machine and human readable (meaning that you and I can understand it, hopefully) and can be used by several other languages, such as RSS, which many online newsreading applications work with.
Our XML datalinq requires that the XML file be on the system itself. However, for online datalinq, you might want to use RSS. This way you have online access to an XML file!
http://en.wikipedia.org/wiki/XML
I hope you found this useful Rene.
#XPression