Modularization and granulation are key concepts in educational content management, whereas teaching, learning and understanding require a discourse within thematic contexts. Even though hyperlinks and semantically typed references provide the context building blocks of hypermedia systems, elaborate concepts to derive, manage and propagate such relations between content objects are not around at present. Based on Semantic Web standards, this paper makes several contributions to content enrichment. Work starts from harvesting multimedia annotations in class-room recordings, and proceeds to deriving a dense educational semantic net between eLearning Objects decorated with extended LOM relations. Special focus is drawn on the processing of recorded speech and on an Ontological Evaluation Layer that autonomously derives meaningful inter-object relations. Further on, a semantic representation of hyperlinks is developed and elaborated to the concept of semantic link contexts, an approach to manage a coherent rhetoric of linking. These solutions have been implemented in the Hypermedia Learning Objects System (hylOs), our eLearning content management system. hylOs is built upon the more general Media Information Repository (MIR) and the MIR adaptive context linking environment (MIRaCLE), its linking extension. MIR is an open system supporting the standards XML and JNDI. hylOs benefits from configurable information structures, sophisticated access logic and high-level authoring tools like the WYSIWYG XML editor and its Instructional Designer.