Open source software

Open-source software means that the source code behind software is made openly available, together with a licence that allows others to use, inspect, modify, and share it. This distinguishes it from proprietary software, where users normally do not have the right to freely inspect, modify, or further develop the code. For software to be truly open, the source code needs to be available in a format that can be read and modified, and the licence needs to allow reuse, modification, and further distribution.

In research, open-source software can be an important part of open scientific knowledge. Software is used to collect, process, analyse, visualise, and share research data, and the code can therefore be crucial for understanding how research results have been produced. When source code that forms part of the research process is shared openly, it becomes easier to scrutinise methods, reuse tools, reproduce analyses, and build on previous research. For this to work in practice, the code often needs to be accompanied by documentation, information about the technical environment required to run it, and, where possible, open data.

Open-source software can also contribute to more sustainable and independent digital research infrastructure. When software can be used, improved, and maintained by more people, dependence on specific suppliers can be reduced, while transparency, collaboration, and reuse are strengthened. However, this requires the software to be documented, secure, maintained, and organisationally embedded. In the European Commission’s work to bolster the EU’s digital autonomy, open source is highlighted as a way to strengthen open digital ecosystems, long-term sustainability, and greater control over digital infrastructure.