The mission of the Social Learning Software Lab [SL]2 is to learn more about how social software can promote learning and collaborative research in a virtual environment. Our researchers design, build, and test tools that let groups of learners express their individual views and questions, respond to the ideas of others, collaborate on shared learning goals, and otherwise interact in ways that promote learning. In [SL]2 we learn about social software by creating it and studying how learners use it.