[Zope] CMFBackTalk

In the Plone documentation it is stated that the CMFBackTalk product is used to build the documentation. I would like to use this product in my Plone site to enable the creation of on-line manuals. Does anyone know where I can get this product from? From the Plone docs under Appendix D: "The Plone book uses CMFBackTalk, based on Backtalk, orignally developed by Chris McDonough. CMFBackTalk is developed by Kapil Thangavelu with some minor hinderances from Andy McKay." Thanks in advance.