It would be nice to have SVN book versions on the website that have a differing portions of the text in blue for changes, and green for new additions and red for now obsolete parts.
It would make re-reading the book
for a new version much easier for old hands, you could immediately spot
everything you need to reconsider.
So, if I upgrade from 1.6 to
1.7, I would like to have the normal 1.7 book, the 1.7/1.6 'blue/green'
version and the 1.6/1.7 'red' version.
(blue & green might not be possible to automate, but even just the blue version would be very useful, or perhaps it's even possible to have this all in one version.)