XML is a way to put metadata into text. the metadata structures the text into records and attributes. It just SUCKS ASS to read or type. I just came across YAML while looking at a text mode news aggregator I saw on Adam's blog. YAML looks like it accomplishest the same thing as XML, but is more readable. Im not sure how it deals with verifying the correctness of a document (xml schemas) or namespaces. It has the whitespace-as-syntax that python has, which im not crazy about.