In this chapter, we present the Web-based carpooling system ORISS, which was initially developed by a student project group at University of Oldenburg. It is currently being deployed at Carl von Ossietzky University of Oldenburg with support of the DBU (Federal German Foundation for the Environment). We describe the role of carpools in traffic, particularly in commuter traffic, and show perspectives of an increased usage of carpools. A significant impact on the eco-balance of the university can be expected. We explain how Internet technologies and geographic information systems can be used for the arrangement of carpools, and show advantages over traditional methods of carpooling. The concrete architecture of ORISS and the algorithms used are outlined. We conclude the chapter by describing the circumstances of deployment and propose possible future extensions of the system.