At a time where computer technology is putting human lives and work under pressure, we discuss how to provide alternatives. We look back at Participatory Design (PD) which was originally about possibilities and alternatives as much as it was about specific solutions. The paper aims to revitalize and revise PD to help people influence big issues. The agenda for this is set through proposing a set of key elements for realizing new, important possibilities. We discuss the possible changes of partnership with users, call for a new role of researchers as activists, debate how to work with demanding visions for lasting impact, and democratic control. We focus on high technological ambitions, on deployment of working prototypes, on alliances, and on scaling up, all seen as important for a PD that matters. We conclude the paper with an invitation to participate in the continued discussion, codesign, and realization of a PD that matters.