Software plays a critical role in today's global information economy. Software runs the computers, networks and devices that enable countless products and services from vast enterprise and communications systems to small 'apps' that run on digital phones. The software industry is a powerful wealth creator, generating billions in revenues, millions of jobs, countless new companies and innovative business models. The industry is intensely competitive and has undergone a dramatic transformation from its roots in a handful of hardware mainframe producers in the 1960's to numerous large and small software firms today. Fundamental forces have shaped the evolution of the industry, starting with the emergence of personal computers, the development of computer networking and client/server software, and the introduction and widespread adoption of the Internet. These transformations have spawned novel and disruptive business models to create, sell and distribute software. The industry is organized into three major segments: system infrastructure software, applications software, and applications development and deployment software. The competitive dynamics differ considerably in the different segments. Some segments are mature and only one or two firms dominate while other segments are emergent with a number of players. This book will offer a brief overview of the software industry; describe its history; explain how the industry works; discuss the economics and competitive environment; and cover trends including globalization of the software industry and the emergence of new software business models.