You're quite right that "framework" is a broad (and sometimes misused) term. I go into that in some detail in the book, and the frameworks reviewed are divided up by category to make it clearer (e.g. whole-application frameworks, persistence frameworks, presentation/UI framworks, etc)

I thought Xerces was just a tool/API as well at first, but with bit of digging I found it actually is more of a framework, with pluggable implementations, a component structure, several different APIs, etc. That's why I thought it made an interesting example on the "border" of what a framework is.

Mike