"In 1455, Gutenberg invented the printing press -- but not the book as we know it. Books printed before 1501 are called incunabula; the word is derived from the Latin for swaddling clothes and is used to indicate that these books are the work of a technology still in its infancy. It took fifty years of experimentation and more to establish such conventions as legible typefaces and proof sheet corrections; page numbering and paragraphing; and title pages, prefaces, and chapter divisions, which together made the published book a coherent means of communication. The garish videogames and tangled Web sites of the current digital environment are part of a similar period of technical evolution, part of a similar struggle for the conventions of coherent communication.
Now, in the incunabular days of the narrative computer, we can see how twentieth-century novels, films and plays have been steadily pushing against the boundaries of linear storytelling."
— Janet H. Murray, Hamlet on the Holodeck: The Future of Narrative in Cyberspace (info)