The term Community of Practice (CoP) is often used rather loosely to describe many types of instructional settings that support more constructivist or social learning settings. This study differentiates CoP from other learning communities with greater discipline in defining CoP, as characterized by sustained self-organization for example. Such a CoP sits quite apart from the typical intent of instructional settings. The literature on intentional CoP suggests that the greatest challenges are a sense of interdependence among CoP members, the authenticity of the practice or purpose, and a trajectory for the CoP's future. The purpose of this case study was to attend to these issues with an online initiative to nurture CoP among practicing teachers in a reading-specialist, graduate program. For the course under study, learners engaged only in cooperative projects with the support of a community worksite (Sakai). Throughout the term, the worksite was promoted as a community place independent of the course and program, a place where they could continue to share indefinitely; and they were encouraged to think of what formal and informal activities the system could support, and how. The study explored how participants responded verbally and behaviorally to the community worksite and the other technologies employed to better support their group work and sharing of knowledge in general. The group's technical skills, competing cultures and practices, and the level of authenticity were all significant challenges. The study's findings challenge the application of this learning theory at the course level of academics, and they inform future design of online support for intentional CoP.