XQuery processing: practice and experience

A special issue of the IEEE Data Engineering Bulletin has just been released; the special issue is focused on XQuery, specifically on existing implementations and the areas in which those implementations specialize.
We have contributed an article to the Bulletin's special edition; you will find in there many of the concepts that we usually cover in various forms in this Blog.
The whole set of articles provided by the various authors looks very interesting to me; reading them I did learn a lot about the specific aspects on which popular XQuery implementations are focused; hopefully you too will find it an educational reading.