Appendixes. The index. And then some information about me (the author), and a colophon. And then probably some advertising for the other great O’Reilly books.

Seriously, though, we’ve covered quite a bit of information at this point. Taking a few days to let the material sink in, and then trying to apply your new XML skills on a project for work, or maybe something personal, should help you polish your XML knowledge. Soon you’ll be an XML wizard, and find your applications’ value increasing as they are more flexible, configurable, and productive. Finally, you’ll see your value to your boss (and lots of potential bosses at other companies!) dramatically rise as you code maintainable and performance-driven applications. Have fun, and stay extensible.