I know it's next to nothing, but in case you happen to need it, I've got some XML-related MySQL utilities.
- A documented XML Schema of the mysql command line utility xml format
- A little windows batch file that exports schema-related metadata in the ordinary mysql command line utility xml format
It's all as-is of course but this time, I explicitly included a couple of lines saying that the usage is all under GPL license.
Regarding the information_schema dump, there are some more tools in the works, among which is a xslt stylesheet that generates human readable documentation for a database schema in html format. As soon as I feel these tools are usuable to others, I will make them available too.