Jupyter
Project Jupyter exists to develop open-source software, open-standards, and services for interactive computing across dozens of programming languages. There's a number of vendors offering Jupyter notebooks as a managed service.
The notebook ecosystem has a variety of tools with both proprietary and open-source licenses. It’s incredible to see how much of the notebook space is open-source. Jupyter in particular can be credited for notebooks as we know them today.
Below is a list of open source notebook tools.