Jupyter - Project Jupyter exists to develop open-source software, open-standards, and services for interactive computing across dozens of programming languages. Ready to get started? Try it in your browser Install the Notebook.

Observable - Interactive code examples/posts

Colaboratory - Free Jupyter notebook environment in the cloud.

nbviewer.org - Rackspace server host Jupyter Notebooks from your github repo

Wolfram Mathematica - Mathematica has characterized the cutting edge in specialized processing—and gave the chief calculation environment to a large number of pioneers, instructors, understudies, and others around the globe.

Binder - Turn a Git repo into a collection of interactive notebooks