To address social-environmental crises and corporate short-termism, the New Economics Foundation advocates rethinking corporate ownership and purpose. Cooperatives, being democratically managed, offer a model with potential for positive impact. Despite growing interest in platform cooperativism, software worker cooperatives remain under-explored. In this study, the first of its kind, we analyse 76 cooperative software businesses, and present insights based on interviews with members of 23 companies. Findings reveal that members are motivated by both practical benefits and ideological alignment with Social Economy values. These businesses promote workplace democracy, stakeholder engagement, and long-term value creation, though impact measurement remains a limited practice. With broader educational, institutional and governmental support, cooperatives could play a transformative role in the software sector.