Since the beginning of the discipline, eLearning has been about innovation. New software, systems, contents and tools are being created and experimented with and in constant evolution. But when systems, contents and tools become successful and part of the regular infrastructure of educational institutions, interoperability becomes an issue. Systems that are consolidated and regularly used need to be able to interoperate with new ones. And the new tendencies need to fit within the current infrastructure. This paper states how several research and development projects with heterogeneous funding sources and locations worldwide, gathered together to find a solution to this common problem, providing open specifications and standards, plus Free/Libre, Open Source reference implementations.This work has been funded by the “Spanish Ministry of Science and Innovation” (http://micinn.es) in project LearningApps in the program INNPACTO 2010, the project MiPLE code TIN2010-21695-C02-02.8 and Google Research Award.Peer ReviewedPostprint (published version
