Though there are many examples of attempts to create interactive lighting installations in urban public space, its meaning for urbanites has not been fully explored and defined. What could interactive lighting contribute to urban public space? Using the concept of Third Place, this research focuses on the social potential of urban public space using the concepts of, especially the role of space in connecting people and fostering social capital. Our hypothesis is that interactive urban lighting can assist this role of urban public space. Openlight is a concept of networked interactive lighting that provides urbanites with open access to penetrate psychological barriers between individuals and groups in urban public space. Hence the interaction would provide more possibilities for urbanites becoming more aware of and getting to know each other. For this first attempt, we have created a scaled prototype for a Café/Restaurant setting.