The use of Augmented Reality (AR) offers great learning opportunities and challenges for educators. There are many examples of the application of AR to education. Furthermore, different libraries and frameworks have been proposed for the development of AR learning content, some of them based on the use of authoring tools. In this context, the present work introduces and describes FI-AR Learning, a web-based platform for the development of AR educational content, the distribution of which is accomplished through standard Learning Management Systems (LMS) by means of SCORM packages. Contrary to most existing solutions, the visualization of the AR learning content is performed without using plugins or specific applications. This is accomplished because FI-AR is based on the European open-source software framework FIWARE. Therefore, FI-AR uses standard web technologies, providing potential universal access. FIWARE also eases many non-educational management tasks, such as registration, security, marketing or billing, providing several important advantages to the FI-AR learning framework compared to other works. The paper describes the architecture and implementation of FI-AR, and several tests intended to measure its usability and performance. In addition, a specific example of application is presented, although the platform is designed to support AR educational content of any subject.