The awareness of language that culminated in France with the French Revolution has remained dominant till the present day: a nation une et indivisible corresponds to a concept of the national language as a homogenous entity, self-sufficient and free from outside and dialectal influences. This conception is contradicted by two historical facts, however. Firstly, various waves of language contact were constitutive of the emergence and development of the French language from the very beginning. Secondly, a new structure of varieties developed through the colonial expansion of France outside Europe, in which many forms of language contact are of significant importance. The best way to capture this diversity adequately is to adhere to a broadly ecological approach (linguistic ecology) that takes into account various parameters, such as history, social context, competence, and universals. This is demonstrated with samples of transcribed speech from Togo, Guadeloupe and Nova Scotia. The linguistic ecology approach is the guiding principle of all the articles in this volume.