1 January 2018Market information systems (MIS) developed in two steps in developing countries. A first generation of MIS emerged in the 1980s when most developing countries liberalized their agriculture, and a second generation followed in the 2000s driven by various factors such as the difficulties faced by the MIS of the first generation to reach their objectives, the new opportunities offered by the development of ICT – Internet and cell phones – and the increasing organization of market players (farmer organizations, interprofessional organizations). Contrary to first generation MIS (1GMIS), which were almost all built on the same model, 2GMIS developed many technical and organizational innovations, giving birth to a great diversity of models. What are the main innovations developed by 2GMIS? What are currently the main MIS models? To what extent can these new models allow MIS to overcome the limitations of 1GMIS to reach their objectives (improve markets and/or inform policies through market information)? What do we know on MIS impacts? This article and the special issue it introduces address these questions.