Namespaces are great when used wisely: they allow for embedding unrelated XML fragments in your document and your application will not see them. Or versioning your XML in namespaces. XPath and namespaces are trivial but it depends on the library you use on how to setup the namespace resolving. My pet peeve about namespaces: people that use HTTP URLs for their declaration and expecting them to be resolved for some reason. The other one being people that see a namespace prefix and think that that is the actual namespace.