An active e‐course is an open, self‐representable and self‐organizable media mechanism. Its kernel idea is to organize learning materials in a concept space rather than in a page space. The tailored content and flexible structure of the e‐courses can be dynamically formed to cater for different learners with different backgrounds, capabilities and expectations, at different times and venues. The active e‐course can also assess learners' learning performances and give appropriate suggestions to guide them in further learning. An authoring tool for constructing course ontology and a system prototype have been developed to support an active e‐course, enabling a learner‐centred, highly interactive and adaptive learning approach. The results of an empirical study show that the system can help enhance the effectiveness and efficiency of learning. Copyright © 2005 John Wiley & Sons, Ltd.