Last updated at 3:37 am UTC on 29 August 2018
A Jupyter Notebook is an open-source web application that allows you to create and share documents that contain live code, equations, 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.