Semantic, or descriptive, mark-up, embeds additional information in a text file by applying labels to fragments of text. This information can be interpreted by software in all kinds of useful ways such as to generate an index or to create automatic hyperlinks to specific learning contexts. It allows great flexibility, allowing multiple output formats to be batch produced from a single marked up source text. Semantic mark-up is the foundation for knowledge management in educational institutions. It enables knowledge capture, reuse and efficient retrieval. For researchers looking into the next generation of semantic learning environments, it places whole domains of programme materials at their fingertips for experimenting and exploring new teaching and learning methods. Extensible mark-up language (XML) is one of the most important semantic mark-up languages and is used extensively for documents and publications. It provides a solid foundation for learning materials, giving them longevity and reusability. The electronic formats used by CAPDM are based on open standards and are non-proprietary – so there is no vendor lock-in. Efficient production processes and capabilities substantially reduce updating and development costs. The resulting materials are of much higher quality – consistently fit for purpose for all delivery media and languages.