I am a big fan of Tav's manual and I was happy to buy the Scribus official manual, in part because it is a way to support the development and also because it is authored and edited directly by the development team.

I am a bit confused by the several manuals for Inkscape (and buying them all is not really an option), and I understand that anyone putting so much effort to create and update a manual would want their work rewarded, I am wondering if there is some intention to have an official manual some day.