Open, online learning environments, such as MOOCs (Massive Open Online Courses) and open learning communities have been promoted as a way to expand equitable access to quality education. Such learning experiences are potentially enriched via extensive networks of peer learners. Even though challenges exist to realize these aspirations, open, online learning environments can serve as a mechanism for how we provide transformative learning experiences. This workshop aims to bring researchers, designers, and practitioners from diverse disciplinary backgrounds to explore how the body of CSCW knowledge can better support the vision of sustaining peer-to-peer learning in online environments.