It wasn’t ´created’ for the three languages at all. Originally the whole project was ‘IPython’ and then ‘IPython Notebook’. It came out of Fernando Perez’s att

It wasn’t ´created’ for the three languages at all. Originally the whole project was ‘IPython’ and then ‘IPython Notebook’. It came out of Fernando Perez’s attempt to make interactive Python a better experience. They renamed it Jupyter to reflect that it was no longer a pure Python project as kernels were written in even before it rebranded as Jupyter. Those three were the most popular at the time but by no means the only ones. I used to work with one of the core team about the time they changed this!