Observable - Interactive code examples/posts
Calculist - The open-source, web-based thinking tool that facilitates effective thinking for solving problems.
nbviewer.org - Rackspace server host Jupyter Notebooks from your github repo
Bl.ocks - Simple viewer for sharing code examples hosted on GitHub Gist.
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.
Carbide - A new kind of programming environment