Choosing an XML Schema: DocBook or DITA?
http://www.thecontentwrangler.com/article/choosing_an_xml_schema_docbook_or_dita/

Hamilton, Richard
Content Wrangler, The
2008

Abstract:

If you follow the latest trends or have been to a conference recently, you may find the idea of choosing an XML schema puzzling. Isn't the question really, 'How should I customize DITA to do what I want'? While there are many good reasons to choose DITA, it's not the only schema in town.