YAI: creation of open learning resources by aggregating metadata to shared educational contents

Class preparation can often be quite time-consuming and includes the gathering of different sources as well as the transformation of selected contents into new contents better suited to specific contexts of use. An infrastructure is presented that allows to: (a) share contents produced by the community and held in an open directory, and (b) create complex open learning resources by aggregating metadata to open contents that are useful for guided tours within the open directory. Annotated trails cross the hierarchical structure of the directory in order to show to the user how different contents might relate to each other.