What's a codex? Well, find a book. Pick it up. You are holding a codex. "Codex" describes the style of book that we are most accustomed to in the modern world - one with separate bound pages surrounded by a cover.

I just started reading The Evolution of the Book, by the late Frederick Kilgour. Kilgour was an American rock star librarian who was interested in computerizing book catalogues to aid information access. The Evolution of the Book includes a timeline of book formats. Kilgour mentioned that the papyrus scroll was around for about 2100 years before the codex was invented. Apparently, as the codex increased in popularity over time (over a loooong period of time), not all works on papyrus scroll were copied over to the new book format, and many volumes of... who knows? where lost.

Kilgour calls the invention of the Electronic Book the "Seventh Punctuation" of book technology. So, while we begin the transition to electronic book formats, let's make sure that we copy over all the information in the codices this time.