Associative rings that possess Morita dualities or self-
dualities form the object of this book. They are assumed to
have an identity and modules are assumed unitary. The book
sets out to give an extensive introduction to thisclass
of rings, covering artinian rings, ring extensions, Azuma-
ya's exact rings, and more. Among the interesting results
presented are a characterization of duality via linear com-
pactness, ring extensions with dualities, and exact rings.
Some basic knowledge of rings and modules is expected of the
reader.