In fact Jupyter is just a mashup of Julia, Python, and R (no TeX). The commenter may have been thinking of Pluto¹, which is Julia-only but a big improvement over Jupyter.
1 ‘An introduction to pluto’. LWN. Available from: https://lwn.net/Articles/835930/
yes, jupyter is more or less a generalization of ipython, which has been around since 2001. the notebook aspects and language agnostic parts were split off to target python-like languages (julia and R), while ipython became a python kernel for jupyter (like irkernel and ijulia).
