This paper is part of a three-year inquiry that supports and investigates the work of groups of mathematics teacher educators using technological tools to design and implement multimedia practice-based teacher education curriculum materials. This paper describes the kinds of activities, interactions, and tools used by mathematics teacher educators to engage in such work. Using Engeström's Activity Theory as a framework, we organize our observations of the groups' work sessions, noting differences across the groups' objectives and ways of organizing the division of labor and tools for engaging in the work. Our results suggest the activity of collective curriculum development amongst teacher educators can take on at least three distinct types of interactions. We present these types of interactions as "caricatures" (Lambdin & Preston, 1995), using data from all of the groups to represent composite descriptions. [For complete proceedings, see ED581294.]