This paper is a July 1999 snapshot of a "whitepaper" that I've been working on. The purpose of the whitepaper, which I initially drafted in April 1999, was to formulate and put into prose my thoughts on the research opportunities XML brings to the general area of data management. It is important to know that this paper is not a survey. It offers my personal opinions and thoughts on Data Management for XML, fully incorporating my biases and ignorances. Related work is not discussed, and references are not provided with the exception of a handful of URLs. Furthermore, I expect the whitepaper to evolve over time; please see http://www-db.stanford.edu/~widom/xml-whitepaper.html for the latest version.