Observable - Interactive code examples/posts
Google Open Source - All of Googles open source projects under a single umbrella
nbviewer.org - Rackspace server host Jupyter Notebooks from your github repo
Open Source @IFTTT - A collection of IFTTT OSS projects.
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.
Code NASA - 253 NASA open source software projects