Floss (Free/Libre Open Source Software) is a wiki host for open source software documentation. Books on Floss are like Drupal collaborative books. They allow individuals to create chapters to add to a book, and edit existing chapters. Users can then print or export a PDF of the entire book. What Floss offers that is different is the ability to remix books by selecting individual chapters, dragging them into a new book, changing titles, and saving off their new creation. It's a nice idea for users that only want to select parts of a book to save, or insert chapters from other books to create an entirely different book to save. How's that for flexibility?