Pressbooks - Create books: print and ebooks
Sigil - Sigil is a multi-platform WYSIWYG ebook editor. It is designed to edit books in ePub format.
bbPress - bbPress is forum software with a twist from the creators of WordPress.
Calibre Web - Calibre Web is a web app providing a clean interface for browsing, reading and downloading eBooks...
ForumWP - ForumWP is a modern forum plugin for WordPress.
calibre - Ebook manager, viewer & converter