Originally it was envisioned that the entire course would run online, in the browser. This would include the virtual laboratory that would be based on the offline CLASS model (available as a download for Windows, Mac and Linux). The online version of CLASS was intended to be developed in a Jupyter notebook that could be served online from a Jupyter notebook server.
During the development of the course, and in particular during the pilots with students, it turned out that the offline version of the CLASS model served equally well as a virtual laboratory. Given the fact that it is available for all major operating systems (the cross-platform availability of a browser-based solution was less relevant. Therefore it was decided to halt the further development of the Juptyer notebook version of CLASS (CLASS-notebook) for the duration of the project.