This paper presents a masters level geographic information systems and science course (CASA0005) developed by the Bartlett Centre for Advanced Spatial Analysis (CASA), University College London (UCL). CASA0005 is a compulsory module for both MSc programs within the department, running annually in the autumn term with between 100 and 150 enrolled students. During the summer of 2019 the module was transformed from static practicals with some legacy content related to commercial software to an online interactive book primarily for the open source R data science programming language written using the Bookdown package (Xie, 2016).