Current procedures and best practice examples from theoretical chemistry and theoretical physics are mentioned here to illustrate the handling of research software, in particular with regard to enabling access to research results. The case studies concern both the use of software and its development.

Case 1: Researchers use purchased software

Only commercial software is used, both for the simulations and for the analysis and visualisation of data. Users do not have access to source codes. In their scientific publications, users provide full details of the software manufacturers, release dates and version numbers (incl. bug patches).

Case 2: Researchers use software provided by colleagues

Software is used that was provided by a colleague for a specific project. Only an executable programme was provided, no source code. In their publications, users make reference to the original work done by their colleague and the latter is thanked for providing the software in the acknowledgements.

Case 3: Researchers develop software for a commercial package

In the context of a cooperation agreement between a software company and a higher education institution, a working group develops simulation software that is needed both for the institution’s own research and for commercial exploitation. The research focuses on the development of innovative methods and algorithms. Publications refer to the “developer’s version” of the computer programme. After a time delay (e.g. one year), the software manufacturer makes the new software available as part of an official release version of the software package.

Case 4: Researchers develop and use their own software

Self-written software is used, both for the numerical simulations and for the analysis and visualisation of the data. On request, the software is made available to colleagues, possibly only as an executable programme, i.e. without source code. Publications include extensive debate of the algorithms and mathematical equations used.

Case 5: Researchers develop open source software

A group of researchers develops and uses software under an open source licence, e.g. the GNU General Public License Version 3 (GPLv3). Publications include extensive debate of the algorithms and mathematical equations used. Software that is constantly evolving is secured when used for a publication by archiving the source code (e.g. via Zenodo) and indicating the version number.