James Bridle discusses the near infinite malleability of digital books. From booktwo.org:
Imagine a book that told a different story every time it
was opened. The story might change depending on the gender
of the reader, or the sex. It might depend on the location
of the reader, or the position of the book in time; the time
of day, or time in years. Centuries might pass before the
book tells the same story again.
The nature of the web makes such a book possible. Immediately,
a simple reading of the user-agent to determine the reader’s
operating system and browser could be used to present each with
a different version, breaking the narrative along several
general pathways. Sections could be hidden or revealed by
simple manipulation of the layout.