Blurt - Compose efficiently. Edit smartly. Stay on track. Blurt is all you need to write — in one sleek tool.
Observable Notebooks - The portfolio and technical blog of Chris Henrick – provider of professional web development, data visualization, GIS, mapping, & cartography services.
Ulysses.app - A powerful writing tool for Mac, iPad, and iPhone
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.
Haven - Personal space security app, backed by Snowden
BeakerX - Open Source Polyglot Data Science Tool