The computer support of cooperation and knowledge production across socially distributed activity systems has become an important topic in the context of the discourse on ,,knowledge management". The present article will draw on concepts of cultural-historical activity theory to discuss the problem of how the notion of ,,knowledge" is conceptualized and implicitly implemented in computer systems to support knowledge management, often neglecting the social embeddedness of knowledge production in everyday work practices. From the point of view of cultural-historical activity theory we would propose to look upon the generation of knowledge as a process embedded in socially distributed activities that are constantly being reproduced and transformed in and between specific communities of practice. The concept of cooperative model production is highlighted as a means to mediate, not to eliminate, differences of perspectives involved in the course of systems design. Empirical resul...