Daisy: WYSIWYG Wiki for PDF Books
http://blogs.sun.com/coolstuff/entry/daisy_wysiwyg_wiki_for_pdf

Armstrong, Eric
Sun Microsystems
2008

Abstract:

If you need the collaborative aspects of a Wiki combined with DITA's modular topics and publishing capabilities, then DAISY might just be the system you need--and it's free. DAISY provides WYSIWYG editing for Wiki pages that can be combined to publish books, either in a PDF or as a single HTML page.