Google’s NSXMLDocument Replacement for iPhone
If you’re missing a decent Objective-C DOM-based XML library for the iPhone, Google has a NSXMLDocument replacement available under the Apache license, as part of their Objective-C GData Library:
See XMLSupport and GDataDefines.h
I’ve also had some success replacing missing classes using the Cocotron implementations — I’m using Cocotron’s NSPredicate implementation for selective receive in my message-passing actor [wikipedia] library.