I can see why you'd say it's ML, but Jupyter is a "notebook" or kind of "literate programming" environment for Python (originally) and other languages, a kind of REPL on steroids.
You see it in a lot of ML examples around the Internet because it's a pretty good way of demonstrating and documenting ML for tutorials.
Also it's split into a frontend "client" for the UI and a backend "server" (also called a "kernel") for computation. The client doesn't need any of the Fortran BLAS stuff, only the backend, which runs in a completely separate process and communicates over network ports.
You see it in a lot of ML examples around the Internet because it's a pretty good way of demonstrating and documenting ML for tutorials.