I am using Xerces to parse an XML Schema annotation. I stumbled across two intesting situations when dealing with Xerces PSVI:

1. The contents of an annotation can only be retrieved as a string. It would have been nice to have access to a Node object instead.
2. When using XPath, one must provide their own NamespaceContext object when using namespaces. Why a trivial implementation that was backed with a Map of strings was not provided I cannot guess. (This isn't specific to PSVI but this is the first time that I'm using Xerces rather than dom4j which provides SimpleNamespaceContext via jaxen.) Stefan Podkowinski has felt my pain. The O'Reilly Network has code for an implementation.

As a side note to the NamespaceContext: if you have a default namespace in the XML that you are parsing then you must have a blank namespace (not null but "") registered with the NamespaceContext.