The use of open-source software (OSS)--readable software source code that can be copied, modified, and distributed freely--has expanded dramatically in recent years. The number of OSS projects hosted on SourceForge.net (the largest hosting Web site for OSS), for example, grew from just over 100,000 in 2006 to more than 250,000 at the beginning of 2011. But why are some projects successful--that is, able to produce usable software and sustain ongoing development over time--while others are abandoned? In this book, the product of the first large-scale empirical study to look at social, technical, and institutional aspects of OSS, Charles Schweik and Robert English examine factors that lead to success in OSS projects and work toward a better understanding of Internet-based collaboration. Drawing on literature from many disciplines and using a theoretical framework developed for the study of environmental commons, Schweik and English examine stages of OSS development, presenting multivariate statistical models of success and abandonment. Schweik and English argue that analyzing the conditions of OSS successes may also inform Internet collaborations in fields beyond software engineering, particularly those that aim to solve complex technical, social, and political problems.