International audienceSince the 1980s, monetary innovations have been developed by and for populations with strong local communities. These “social technologies” are intended to transform living conditions, though with various aims : building friendly and participatory communities, improving household incomes, funding activities and local projects, and sustainability. They promote short monetary circuits through the mobilization of several forms of proximity. This text briefly introduces their dynamics by presenting four types of alternative currencies : local exchange and trading systems, timebanks, non-convertible local currencies, and convertible local currencies.Depuis les années 1980 se développent des innovations monétaires par et pou...