This chapter introduces the wide-ranging textual culture which grew up in medieval Iceland and generated the enormous variety of Old Norse-Icelandic written texts. It details the present-day locations of the major collections of Icelandic manuscripts and gives an account of how these manuscripts were preserved and what proportion of them may have been lost. An account of the origins of manuscript production in Iceland and its subsequent history follows, with criteria for dating manuscripts and discussion of different scripts. The effect of the introduction of the printing press is noted. Recent new approaches to manuscript studies, including codicology and greater attention to paper manuscripts and the physical processes of manuscript-making, are also covered. The chapter moves on to address digitization and the standardization of online texts, and concludes with discussion of what the future may hold for manuscript studies, including collaboration between palaeographers and scientists such as geneticists, ecologists and chemists, and the emergence of a new discipline of biocodicology, enabling a holistic examination of the interplay between many different environmental factors.