Sorry to write in English, my French is really mediocre. Anyway, is there a way to make your excellent tool work for Wikibooks as well? There used to be an epub and odt export script there, but it's broken now and you can only export collections and books to pdf or plaintext using Special:Book (which is not very handy).
Sujet sur Discussion utilisateur:Tpt
Hello Halibutt! Sure, it's definitely possible. I've started with a very early implementation. Go to http://tools.wmflabs.org/wsexport/tool/book.php and use as language parameter "enwikibooks" or "plwikibooks".
Wsexport have been created with just Wikisource in mind so having something well suitable for Wikibooks won't be trivial.