Technology plays a pivotal role in driving transformation through grassroots movements, which operate on a local scale while embracing a global perspective on sustainability. Consequently, research emerged within Sustainable HCI, aiming to derive design principles that can empower these movements to scale their impact. However, a notable gap exists in contributions when addressing scalability of large free and open-source software (FOSS) projects.

Sustainable HCI and Human-Food-Interaction research have developing interest in preventing food waste through food sharing. Sustainability requires attention to both the opportunities and challenges associated with the building of food sharing groups engaged in the redistribution of food but also in developing a wider agenda which includes, for instance, the local production of food resources. In this paper, we argue for a better understanding of the different conceptions of ‘fairness’ which inform volunteer and guest practice and in turn mediate community-building efforts. We examine the practices surrounding ‘SharingEvent’ and challenges faced to sustainability by the heterogenous, and sometimes contested, commitments of the people involved. We further consider how ICT provided opportunities for explicit examination of ideological differences concerning what ‘sharing’ might mean. Our findings show that community building is dependent on the negotiation of different values and purposes identified. We derive recommendations for action-oriented researchers ultimately concerned with systemic transformation.