The Mekong e-Sim involved more than 140 students across Australia and overseas participating in an online roleplay-simulation over a four-week period. Set in the Mekong region of South East Asia, it allowed for debates over development issues arising from clear-cut differences and conflicts in values and interests. The geography and engineering students who participated were enrolled in three different subjects (Asia-Pacific development, technology assessment, and environmental engineering) at four institutions, i.e., the University of Technology, Sydney (Australia), Adelaide University (Australia), the University of Sydney (Australia), and Sepang Institute of Technology (Malaysia). The e-Sim was the product of a grassroots alliance among four collaborators at different institutions. The drivers for forming the alliance were the development of subject-specific learning outcomes, promoting linkages between students, internationalization of the curricula, and educational research. The e-Sim design created a high level of student interdependence for pedagogic reasons, which also led to a high degree of interdependence among staff. This created a need to negotiate and agree to common practices for teaching and assessment in specific areas. Issues regarding access to institutional resources for students across different institutions also arose. An awareness of these issues is needed to ensure that grassroots collaborative educational activities are designed to meet their objectives and can evolve to be sustainable. (Contains 12 references.) (Author/MES)