XMark - An XML Benchmark Project

xmlgen produces XML documents modeling an auction website, a typical e-commerce application. The high-lights of the data generation are:
Generation of well-formed, valid, and meaningful XML data.
Efficient, scalable generation of XML documents the size of several GBytes.
Observing of referential constraints concerning ID/IDREF pairs.
Low, constant memory requirements, independent of the size of the generated document.

http://monetdb.cwi.nl/xml/generator.html