This book explores the transformative role of open-source technologies and digital commons in fostering a cooperative and sustainable economy. Built upon the research project "Techno-Social Innovation in the Collaborative Economy," the study investigates innovative, grassroots economic models that leverage digital technologies for community-driven governance and decentralized value creation. The book presents a multi-case study approach, featuring organizations such as Tzoumakers, Open Food Network, CoopCycle, and Circles UBI. These cases exemplify how platform cooperativism, cosmolocalism, and open cooperativism redefine traditional business structures, emphasizing sustainability, fairness, and democratic ownership. The discussion extends to blockchain-enabled DAOs and their impact on labor, governance, and wealth distribution. Through theoretical and empirical insights, The Model of Open Cooperativism bridges political economy and digital innovation, providing practical strategies for policymakers, activists, and scholars. It highlights the success and challenges of grassroots-driven initiatives, offering a roadmap for transitioning toward a commons-based, post-capitalist economy.