Currently there is a large amount of educational resources available, developed by many educational institutions at all level. One of the main challenges is to make use of such wealth of material in a simple and effective way, especially when pre-university education is involved, ranging from primary schools to high schools. The main difficulties experienced by the teachers willing to tailor the available material to the specific needs of their class are typically the lack of available time and the difficulties in learning the peculiar procedures that each repository system (including CMS, LMS etc.) requires. This work presents an architecture to integrate different repository systems using the Content Management Interoperability Services (CMIS) API, as well as an integration layer that provides a much more simplified interface suitable for the needs of the content creators (i.e., teachers), and the users of the contents (i.e., the learners). Both the technical aspects of integration and the usability issues from the point of view of the teachers are described and considered in the design. The first experiments, evaluated by means of performance indicators and some user feedbacks, show that the platform has the potential for widespread adoption in the Italian educational environment.