The aim of the case study is the discuss the potential of semantic markup for the use of context to improve mathematical eLearning. We are drawing upon the theory of communities of practice [LW91, Wen05] to provide a model for contextualizing mathematical eLearning. In contrast to approaches such as in CSCW (Computer Supported Collaborative Work), we are less interested in supporting social networks and exchange via community platforms to collaboratively contextualize (and manage) the learning material. We rather focus on a community’s shared repertoire, i.e.