During the past few decades, social innovations have moved from the fringes to the mainstream. Often, social innovations are hybrids of existing elements, rather than wholly new inventions. Putting such innovations into practice usually involves cutting across organizational and disciplinary boundaries. With a focus on exploring the pluralism of design roles that are emerging in this space, this cluster is anchored around an investigation of experimental models and tools that leading companies use to promote market-based approaches which can result in transformative social innovations.