Human anatomy is complex in its nature and from the late bronze age to this date people have been trying to understand it. Resources such as books and software exist to train students in their knowledge of the human body. Most books focus on specific parts of the body or try to give a general overview. Images in books present the information from a single view point, since interaction is not possible. Several software tools have been developed to illustrate anatomy. The aims of these tools are diverse, including education, anatomical research, surgical training and pre-operative planning. In this work, we introduce the Online Anatomical Human, an online anatomy browser and annotation system that incorporates medical image data in 2D and linked 3D views. We created a system that is available to everyone and as portable as possible. The application functions as an educational tool where users can not only retrieve, but also add and share information. Our main contribution is that this system is the first of its kind to offer real anatomical data in an online environment with existing linked knowledge and the possibility to add new information. We describe this data as real anatomical data, because it is obtained from medical imaging data and is not based on an idealized average anatomy. Besides tools for exploration of the data, an editor is available for annotations. These annotations can be added to the 3D mesh directly. This information can be used to enrich the model. Since the system runs completely inside a web browser, no installation is required and no data has to be permanently stored on the local machine.