If I could build my notebooks in emacs...
But then org mode has most of the same functionality.
https://github.com/millejoh/emacs-ipython-notebook
Seems the best of both worlds!
Now, is there a elisp notebook (or is it just emacs)?.
You can format text and tables via Markdown, add MathJax equations, etc.
Then you can write down code, evaluate it, and it can evaluate to images as well... charts and such.
You can optionally export the resulting document to HTML and share it in static form, or just share a link to the notebook. In addition, github supports Jupyter notebooks.
I guess it boils down to having a hierarchical vs sequential document as the base form, really.
Jupyter may already be more featured than org-mode through the kernels it embeds. e.g: SageMath alone is gigantic.
Then, if you don't enjoy the web interface you can use it within emacs if so you prefer.