Open source software development represents a new model of innovation that combines elements of both the private investment and collective action models. This "private-collective" model allows users to freely share their innovations without seeking private returns, yet still creates value for society. Open source software projects are developed by communities of volunteers who collaborate to create and maintain software. These projects are characterized by the free availability of source code, the absence of proprietary restrictions, and the involvement of a diverse group of contributors who may not be directly compensated for their work. Open source software development challenges traditional innovation models by demonstrating that users can act as innovators and contribute to the development of software without the need for private investment or proprietary protection. This model is particularly relevant for organization science as it offers a unique opportunity to study the dynamics of innovation, collaboration, and community-based development. The open source model also provides researchers with access to detailed logs of project interactions and outputs, making it an ideal site for empirical studies. The paper discusses the characteristics of open source software development projects, the motivations of contributors, and the implications of this model for innovation theory. It highlights the importance of understanding the incentives that drive participation in open source projects, including the benefits of learning, community involvement, and the development of personal and professional skills. The paper also explores the differences between open source software development and traditional models of innovation, emphasizing the unique aspects of the private-collective model. The paper concludes that open source software development offers a valuable opportunity for researchers to study the dynamics of innovation, collaboration, and community-based development. It suggests that the private-collective model of innovation may provide a more comprehensive understanding of how innovation can be driven by both private and collective incentives. This model has the potential to offer society the best of both worlds, combining the benefits of private investment with the advantages of collective action.Open source software development represents a new model of innovation that combines elements of both the private investment and collective action models. This "private-collective" model allows users to freely share their innovations without seeking private returns, yet still creates value for society. Open source software projects are developed by communities of volunteers who collaborate to create and maintain software. These projects are characterized by the free availability of source code, the absence of proprietary restrictions, and the involvement of a diverse group of contributors who may not be directly compensated for their work. Open source software development challenges traditional innovation models by demonstrating that users can act as innovators and contribute to the development of software without the need for private investment or proprietary protection. This model is particularly relevant for organization science as it offers a unique opportunity to study the dynamics of innovation, collaboration, and community-based development. The open source model also provides researchers with access to detailed logs of project interactions and outputs, making it an ideal site for empirical studies. The paper discusses the characteristics of open source software development projects, the motivations of contributors, and the implications of this model for innovation theory. It highlights the importance of understanding the incentives that drive participation in open source projects, including the benefits of learning, community involvement, and the development of personal and professional skills. The paper also explores the differences between open source software development and traditional models of innovation, emphasizing the unique aspects of the private-collective model. The paper concludes that open source software development offers a valuable opportunity for researchers to study the dynamics of innovation, collaboration, and community-based development. It suggests that the private-collective model of innovation may provide a more comprehensive understanding of how innovation can be driven by both private and collective incentives. This model has the potential to offer society the best of both worlds, combining the benefits of private investment with the advantages of collective action.