DocBook 5: The Definitive Guide is Copyright © 2010 Norman Walsh.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, as spelled out in the book's legal notice.
Version 1.0 is DocBook 5: The Definitive Guide from O'Reilly Media and XML Press. You can get it in electronic or dead-tree form.
Version 1.0.1 is an online version of the DocBook V5.0 book. It is intended to be the same as the published O'Reilly version, possibly with errata applied, using the “expanded” content model view with the dynamic lists.