Shorter than encyclopedia articles but longer than those of a dictionary, 671 entries describe some act, company, machine, or other entity that advanced the development of computing or in the case of theoretical and technological oriented topics was an essential prelude to a later development. Each ends with a list of additional reading. People are not considered. The reference could be useful to high school and college students, and general readers. Reilly has written widely about science and technology. Annotation (c) Book News, Inc., Portland, OR (booknews.com)