Collaboration Via GitHub

Simple resources for collaborating on Jupyter Notebooks via GitHub
  Note: Notebook file extension is *.ipynb

https://nbviewer.jupyter.org/
  A simple way to share Jupyter Notebooks

https://www.tutorialspoint.com/jupyter/sharing_jupyter_notebook_using_github_and_nbviewer.htm
  Github > NBViewer > Binder for interaction

https://cocalc.com/doc/jupyter-notebook.html
  Popular website for interactive web interface recommended by intro courses for data sci/ML
  Note: Git[Hub] interaction with a paid account, notebook execution is available w/o a login

https://github.blog/2015-05-07-github-jupyter-notebooks-3/
  Github blog post on topic

https://github.com/jupyter/jupyter/wiki/A-gallery-of-interesting-Jupyter-Notebooks#general-python-programming
  Link referenced in blog post on interesting examples
  NOTE: GitHub only renders notebooks to HTML, it does not offer any execution

https://github.com/jupyter/nbconvert
  nbconvert :  converts to HTML|MD so can use Git[Hub] for version control

https://nextjournal.com/schmudde/how-to-version-control-jupyter
  "How to Version Control Jupyter Notebook - The Definitive Guide"
  Note: Uses NBDime instead of nbconvert

Also there is Jupyter Labs web based collaboration and a couple hub installs are available.