The European Commission is funding a large-scale research project on federated online laboratories (Labs) for education in Science, Technology, Engineering, and Mathematics (STEM) at School. The main educational focus is on inquiry learning and the main technological one is on personalized learning spaces. The learning spaces are offered through a single European social media portal supporting simultaneously teacher communities and student learning activities. This paper presents the general technical framework devised to support the construction and the exploitation of learning spaces, as well as the federation of online labs