NSXML is a set of classes introduced in OS X 10.4 (Tiger) that deals with a complete XML tree.
It is comprised of these FoundationKit classes:
*NSXMLNode *NSXMLDocument *NSXMLElement *NSXMLDTD (wikified as NSXmlDtd) *NSXMLDTDNode
It does not include NSXMLParser, though NSXML does use it to parse XML.
Apple’s unusually good overview is at < http://developer.apple.com/documentation/Cocoa/Conceptual/NSXML_Concepts/index.html >.
NSXML supports many cool things:
*User data associated with XML elements and attributes *NSValueTransformer *DTD manipulation *XML namespaces *XQuery and XPath *XSLT document transformations (wikified as XSLTransformations) *XInclude *CocoaBindings
In particular, XPath takes all the drudgery out of reading XML values.