Computer assisted learning (or E-learning) is used broadly in the developed world. However, comparable technologies are only recently beginning to be used in rural and developing regions. In these environments, obstacles to the successful deployment of educational software include a lack of basic infrastructure, low student attendance, necessary sharing of resources, and the participants'-both teachers and students-unfamiliarity with communications technology. To illustrate these issues in detail, we present a design study for Metamouse, a system for sharing single user software on a single computer with multiple mice.We designed Metamouse during a one and a half month long study in low-income primary schools in Bangalore, India. We iterated through two primary usage paradigms, competitive and collaborative, working with grade four and five students. In these populations, we found that students had widely varying mouse skills, and that even amongst competent users, interface confusion presented significant barriers. Given this, interface tasks that are known to have a cost in usability, such as mode switching or complicated interaction models, had a severe impact on students' ability to use the technology. We discuss interface issues that result from sharing practices that are the norm in these regions. We also discuss issues that generalize across educational application design in the developing world.