One of the central tenets of modern computer science is that it is a collaborative discipline. The importance of collaboration is emphasized in the new K-12 Computer Science Framework, and collaboration is increasingly emphasized in the computer science industry and by professional societies. Relatedly, curricular frameworks such as the Next-Generation Science Standards also emphasize collaboration and computational thinking as practices that students must engage in “across all grade bands.” Yet, many students reach high school and college without ever learning to collaborate well, particularly with diverse peers. The FLECKS project will create a collaborative computer science learning environment for upper elementary school classrooms, addressing the pressing need for young students to develop fundamental computer science competencies and collaboration practices. This project is led by PI Kristy Boyer at the University of Florida, and PI Eric Wiebe and co-PI Collin Lynch at North Carolina State University.