This accessible compendium examines a collection of significant technology firms that have helped to shape the field of computing and its impact on society. Each company is introduced with a brief account of its history, followed by a concise account of its key contributions. The selection covers a diverse range of historical and contemporary organizations from pioneers of e-commerce to influential social media companies. Features: presents information on early computer manufacturers; reviews important mainframe and minicomputer companies; examines the contributions to the field of semiconductors made by certain companies; describes companies that have been active in developing home and personal computers; surveys notable research centers; discusses the impact of telecommunications companies and those involved in the area of enterprise software and business computing; considers the achievements of e-commerce companies; provides a review of social media companies.