The educational research and development team at Tufts CEEO is currently designing, developing and testing an innovative web-based learning environment called InterLACE (Interactive Learning and Collaboration Environment) to support high school students in carrying out collaborative inquiry-based physics lessons. The InterLACE toolkit will provide both features and teacher-customizable content that encourage discussion, debate, self-assessment, reflection, and collective sense-making. Our goal is to minimize barriers to the successful implementation of collaborative inquiry-based lessons (e.g., time, technology, and inexperience with technology and inquiry based instruction). Over this past year of the project, a Design Team of five teachers has assisted us in developing and testing the software and associated curricula. In the coming year, we are expanding to include 20 teachers as part of the multiyear research and development project.