This paper examines theoretical, pedagogical, and technological differences between two technologies that have been used in undergraduate interprofessional health sciences at the University of Toronto. One, a learning management system, WebCT 2.0, supports online coursework. The other, a Knowledge Building environment, Knowledge Forum 2.0, supports the collaborative work of knowledge-creating communities. Seventy students from six health science programs (Dentistry, Medicine, Nursing, Occupational Therapy, Pharmacy and Physical Therapy) participated online in a 5-day initiative to advance understanding of core principles and professional roles in pain assessment and management. Knowledge Forum functioned well as a learning management system but to preserve comparability between the two technologies its full resources were not brought into play. In this paper we examine three distinctive affordances of Knowledge Forum that have implications for health sciences education: (1) supports for Knowledge Building discourse as distinct from standard threaded discourse; (2) integration of sociocognitive functions as distinct from an assortment of separate tools; and (3) resources for multidimensional social and cognitive assessment that go beyond common participation indicators and instructor-designed quizzes and analyses. We argue that these design characteristics have the potential to open educational pathways that traditional learning management systems leave closed.