progOh, one thing I have managed to do this weekend outside of buying things and then complaining about them: wrote a Perl script that acts as a fascistic gatekeeper to the book's CVS repository. Now if you try to commit a change to any chapter file, it determines whether or not the change would break the book out of DocBook v4.2 compliance; if so, it refuses the commit and passes along the validator's error message to you. This is a very good thing, especially now that there's at least two people working with this stuff. Nothing is more annoying than fixing other people's XML breakages (even if they're no worse than the breakages one regularly submits all by oneself).