Codex Sinaiticus is the name that scholars have given to a near-complete copy of the Bible (Old Testament, most of the Apocrypha, New Testament, and two bonus Christian texts -- the Epistle of Barnabas and Shepherd of Hermas). The entirety is written in Greek, which means that the Old Testament follows the form of the text used by Greek-speaking Jews in the Diaspora (commonly known as the Septuagint). The codex dates from about 400 AD, making it one of the oldest and most important manuscripts for the study of the Bible.