Why are there so many different languages across the world? How come these languages are so vastly different, while at the same time yielding recurrent features? How can we learn, use and process language? At Sony CSL Paris, we tackle these questions by simulating the emergence and evolution of language in agent-based models in which language evolves spontaneously as the side-effect of how communicative agents locally interact with each other, thereby displaying many processes that are also observed in nature but on a cultural level.