Most existing software tools for online collaboration are designed to support the collaboration itself instead of the study of collaboration with a systematic team and task management system. In this report, we identify six important features for a platform to facilitate the study of online collaboration. We then introduce the Educational Testing Service Platform for Collaborative Assessment and Learning (EPCAL), which was developed to encompass these features to enable both large-scale online collaboration itself and the research on these collaborations. The collaboration management features of the EPCAL also make it an ideal tool for teachers to carry out computer-supported collaborative learning and assessment activities in classroom settings.