Versioned Executable User Documentation for In -development Science Tools

One key aspect of software development is feedback from users. This community is not always aware of the modifications made in the code base, neither they use the tools and practices followed by the developers to deal with a non-stable software in continuous evolution. The open-source Python package for gamma-ray astronomy Gammapy, provides its user community with versioned computing environments and executable documentation, in the form of Jupyter notebooks and virtual environment technologies that are versioned coupled with the code base. We find that this set-up greatly improves the user experience for a software in prototyping phase, as well as provides a good workflow to maintain an up-to-date documentation.