Deutsche Bahn uses a modified version of the EUPL, called DB Inner Source Lizenz Version 1.0 („DBISL“). DB started from the EUPL v1.2 text (German version) making some specific additions in order to meet the need of large organisations distributed between multiple different legal entities, like AIRBUS, or industrial consortiums like Bosch, DB itself, Stellantis or GovTech (Singapore).

The context for using a license like DBISL is as follows:

• A large organization with many legal entities (subsidiaries) that want to share code. When the organization gets larger, the value of this pattern increases.
• As per definition, the legal entities have their own legal rights and obligations.
• Multiple of these legal entities are developing software, and are using services of the other legal entities. They have a motivation to contribute to each other’s source code.
• A sufficient complexity of the organization and its organizational structure

The license is aimed to meet the following issues:

• When two or more legal entities within an organization want to share code with each other, they need an agreement about the terms and often a legal contract. Creating such agreements on a per project basis takes effort and creates a barrier for sharing. i.e. a team within a legal entity might decide not to share their source code with another legal entity in the organization because it seems complicated.
• Barriers for sharing can lead to silos and duplication of effort in rebuilding similar solutions in multiple parts of the organization.
• At the time of sharing the source code, it can not be reliably predicted what the value of sharing will be. If the activity of sharing requires significant effort (i.e. negotiating terms for the usage), the legal entities are less likely to do it, as they are concerned about the return on investment.

As stated in the EUPL FAQs, the European Commission makes no barriers for licensors creating and using modified versions (so called “derivatives”) of the EUPL. The main condition is to make clear that the modified license is NOT the EUPL and wore another name. By naming their license DBISL, Deutsche Bahn meets this condition.