Nowadays, web-based learning services are a key topic in the pedagogical and learning strategies of universities. While organisational and teaching requirements of the learning environment are being evaluated, technical specifications are emerging, enabling educators to build advanced "units of learning". Changes, however, take a long time and cost-effective solutions have to be found to involve our institutions in such actions. In this paper, we present a model of the components of a course. We detail the method followed to implement this model in hypermedia modules with a viewer that can be played on line or from a CD-ROM. The XML technology has been used to implement all the data structures and a client-side architecture has been designed to build a course viewer. Standards of description of content (such as Dublin Core and DocBook) have been integrated into the data structures. This tool has been populated with data from a pathology course and supports other medical contents. The choice of the architecture and the usefulness of the programming tools are discussed. The means of migrating towards a server-side application are presented.