This article describes the rationale for pedagogical, technological and organizational choices in the design of a web-based and open virtual learning environment (VLE) promoting and sustaining self-directed language learning. Based on the last forty years of research on learner autonomy at the CRAPEL according to Holec's definition (1988), we designed a global VLE for researchers working on language learning autonomy, teachers with various degrees of practice and experience in self-directed learning, and language learners. The VLE is thus divided into three spaces for the different types of participant, each offering dedicated social networking possibilities and resources to enrich the others. Our study focuses on the space dedicated to teacher training, the main objective being to help them build knowledge and skills for a new educational role in the paradigm of language learning autonomy (LLA). This space contains specially created Web-TV resources and audio podcasts of self-directed learning advising sessions, is based on reflective analysis and relies on a professional social network, following the principles of the "community of practice" (Wenger, 1998). In line with the principles of self-directed learning, teachers acting as trainers in the VLE mainly enact supportive and facilitative functions as advisers do in face-to-face interactions. We explore how training for advisers is organized in this online environment characterized by a high degree of openness (Jézégou, 2010). We report on findings from the way teachers within their dedicated space, using quantitative and qualitative data collected from interviews, questionnaires and analysis of logs. We look at the tensions that emerge as teachers conceive their new role and engage in new training practices given the opportunities afforded by the environment. The data provide insights to how the VLE can support training practices based on reflection, participation and collaboration.