This is volume 78 of Advances in Computers. This series, which began publication in 1960, is the oldest continuously published anthology that chronicles the ever- changing information technology field. In these volumes we publish from 5 to 7 chapters, three times per year, that cover the latest changes to the design, development, use and implications of computer technology on society today. - Covers the full breadth of innovations in hardware, software, theory, design, and applications. - Many of the in-depth reviews have become standard references that continue to be of significant, lasting value in this rapidly expanding field.