This website offers a set of free lessons on such topics as hepatitis infections in relation to needle sticking, vibration white finger in relation to forest work, prevention of further outbreaks of an infectious disease, over-use of the voice in noisy environments, diagnosis of abdominal pain, and risk and prevention in the mining industry. The lessons are presented in three languages: English, Spanish and German. It is necessary to register before the lessons can be approached. Apart from the free lessons, the website offers a large amount of others cases also, however, not for free. Each lesson consists of text, illustrations and questions. Before one can continue, these questions (open or multiple choice) must be answered, whereafter the feedback can be checked. The lessons can be followed and displayed on-line only. The level of the material is variable: some is meant for anyone who has basic knowledge in health care and occupational health. Other lessons demand for advanced knowledge in medicine. Some specific terms used are explained (however: not all).