Last updated at 1:49 pm UTC on 15 May 2019
A Jupyter Notebook is an open-source web application that allows you to create and share documents that contain
- live code,
- visualizations and
- narrative text.
In this sense the notebooks are similar to Active Essays kept in a Smalltalk based Dynabook.
Notebook documents contain the inputs and outputs of a interactive session as well as additional text that accompanies the code but is not meant for execution. In this way, notebook files can serve as a complete computational record of a session, interleaving executable code with explanatory text, mathematics, and rich representations of resulting objects.
The notebook documents are saved in JSON files (examples).
The file extension is .ipynb. As JSON is a plain text format (https://jupyterlab.readthedocs.io/en/latest/ed) the file can be version-controlled and shared with colleagues. , , .
Jupyter notebooks were originally only Python based but now the Project Jupyter exists to develop open-source software, open-standards, and services for interactive computing across dozens of programming languages., 
The execution of scripts in a particular programming languages is done in a 'kernel'. There is a project to implement a Pharo Smalltalk kernel (JupyterTalk ). A kernel needs to implement the Jupyter messaging protocol.
JupyterLab is a browser based solution which needs a server.
The client communicates with the server using a JSON based protocol .
A survey  shows how Jupyter notebooks are used in courses.
Examples of notebooks:
 Jupyter Notebooks – a publishing format for reproducible computational workflows
 Details of the notebook document format https://nbformat.readthedocs.io/en/latest/format_description.html#notebook-file-format
 JupyterTalk = Pharo kernel for Jupyter notebooks; repository: https://github.com/jmari/JupyterTalk
 https://blog.nteract.io/nteract-building-on-top-of-jupyter-9cfbccdd4c1d - has introduction to protocol used.
 https://zenodo.org/record/51701#.W3Er3ta-lE4 2016 Jupyter Education Survey
 https://blog.jupyter.org/jupyter-receives-the-acm-software-system-award-d433b0dfe3a2, https://awards.acm.org/software-system
ACM Software System Award for Project Jupyter, a broad collaboration that develops open source tools
for interactive computing, with a language-agnostic design.
These tools, which include IPython, the Jupyter Notebook and JupyterHub, have become a de facto standard for data analysis in research, education, journalism and industry. Jupyter has broad impact across domains and use cases. Today more than 2,000,000 Jupyter notebooks are on GitHub, each a distinct instance of a Jupyter application—covering a range of uses from technical documentation to course materials, books and academic publications.
 Colaboratory https://colab.research.google.com/notebooks/welcome.ipynb (in the cloud, Python only)
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Jupyter notebook document examples
Wolfram notebooks are similar in aim but not open source and not directly compatible.