In this chapter, the concept of Personal Learning Environment is first refined taken into account recent advances and the experience gathered in a European research project dedicated to responsive open learning environments. A prototypal implementation of a Web 2.0 platform enabling the construction, the sharing, and the repurposing of personal learning environments is then introduced. Participatory design and validation activities carried out in the framework of higher education test beds aiming at understanding the benefits of personal learning environments in academic institutions are presented. Finally, the broaden applica- tion framework for the deployment and the adoption of open user-centric environ- ments for learning and knowledge management is tackled with perspectives in terms of supporting inquiry learning at school with online laboratories, implementing connectivist massive open online courses or enabling agile informa- tion systems for nongovernmental organizations