As the name implies, distance tutors commonly work away from campus and rarely have the opportunity for ongoing support and informal development such as that enjoyed by campus based staff. In this context there is much potential in making provision for the development of online communities. This chapter describes three case studies of the establishment and evaluation of online Communities of Practice (CoPs) at the Open University (UK). CoPs are in use both as a central part of course related professional development, and for wider pedagogical issues. Platforms in use include online forums, which support online discussion, and new wiki environments, which also offer the potential for extending the use of CoPs to the development and sharing of resources. The variety of ways in which CoPs are in use are described, the major factors which contribute to their success, and the social and institutional challenges to sharing and developing resources within a community.