Disordered, as opposed to ordered, proteins cover nearly half of the sequence space in various proteomes, yet to date they have received little mention in references. This work provides the first comprehensive reference on the structure, function, and evolution of intrinsically disordered proteins (IDPs). After an overview of protein science principles, it examines biophysical methods for characterizing IDPs, addressing computational approaches as well as major classes of relevant algorithms. The text also discusses structural and functional classification, including functional advantages...