Development projects usually benefit when expertise is drawn from diverse sources, including potential users. Orchestrating the involvement of disparate groups requires finding a balance between differentiation, when teams work separately, and integration, when groups meet to exchange knowledge. This paper argues that a "community of practice" perspective can help project managers achieve this balance, by drawing attention to the assumptions, interests, skills, and formal and tacit knowledge of the different groups involved. Using a case study as illustration, we show that integration can be achieved by ensuring that the developing technology is comprehensible to all groups concerned, and that it satisfies their various interests.