Whoever controls the platforms, controls the future.  Platform Socialism  sets out an alternative vision and concrete proposals for a digital economy that expands our freedom.Powerful tech companies now own the digital infrastructure of twenty-first century social life. Masquerading as global community builders, these companies have developed sophisticated new techniques for extracting wealth from their users.James Muldoon shows how grassroots communities and transnational social movements can take back control from Big Tech. He reframes the technology debate and proposes a host of new ideas, from the local to the international, for how we can reclaim the emancipatory possibilities of digital platforms. Drawing on sources from forgotten histories to contemporary prototypes, he proposes an alternative system and charts a roadmap for how we can get there.