Please add books about wiki to this list:
Les Wikis (French book, by Jerome Delacroix)
Wiki Book Erik Moeller (German book, sister site link will turn up soon)
Wiki Web Collaboration, by Anja Ebersbach et al. (English translation of a German book, sister site links will turn up soon)
Wiki Book Christoph Lange (German book, sister site link will turn up soon)
Wiki Patterns Book (English book about creating and managing a successfull wiki, based on the website Wikipatterns.com)
See original on c2.com 