Urban land-use planning and management are in constant mutation throughout the world. With sustainability as a goal, the use of participative GIS is becoming more and more in demand. Given the willingness of local authorities to test participatory models and instruments, this paper presents an original implementation of information and communication technologies to support public participation. A system for monitoring urban functionalities (SMURF) was created for supporting participatory planning and management in African cities. The software instrument consists of a geographic database and of spatial indicators, for sharing information, editing information, and evaluating city development. To collect and update data, the model begins with the gathering of the data from each stakeholder, who, in return, gets a better knowledge of the land and a planning support tool. However, the implementation of these technologies presents several challenges: create an adapted interface, elaborate a relevant set of data and indicators, manage the data, and institutionalize the instrument. After an introductory presentation of the context and use of information technologies for the management of African cities, this paper focuses on SMURF and its components. It then shows the experimental application of the software in the city of Thies, Senegal, before concluding with a more general discussion on the relationship between technology, information, knowledge, and participation.