Virtual worlds are a new way for people to communicate, to meet and to socialize. They are now pushing the boundaries of multilingual communication. The need for multilingual support is increasing every day making virtual worlds a very good example of fields of development where applications supporting multilinguality are becoming an absolute necessity. In order to enhance interoperability between virtual worlds, applications and corpora, it is obvious that standards should come into place. This is the main goal of MLIF and, on a more global perspective, of the Metaverse1 project. In this paper, we study social interactions in virtual worlds, present some cues to facilitate them, and describe the empirical support that we developed for these theories. We also present a few methods for fostering language learning in virtual worlds, and we explain how we have implemented some of them.