European Union Public Licence

The EUPL v1.2 was prepared as from June 2013[22] its decision process started in 2016 and [23] released on 19 May 2017. A principal objective of the EUPL v1.2 is to update the appendix of compatible licences to cover newer popular licences such as the GNU GPLv3 and AGPLv3.[23]

According to the EUPL v.1.1, the European Commission may publish other linguistic versions and/or new versions of the EUPL, so far this is required and reasonable, without reducing the scope of the rights granted by the Licence. Future upgrades will not be applicable automatically when software was expressly released "under the EUPL v.1.1 only".[24]

New provisions cover the Application service provider loophole of software distribution: Distribution and/or Communication (of software) includes providing on-line "access to its essential functionalities".[25]

A specificity of the EUPL v1.2 is that, at the contrary of the GPL, it is compatible with all other reciprocal licenses listed in the EUPL appendix. Compatibility means that after merging the covered code with code covered by a compatible license, the resulting (combined) derivative work can be distributed under the compatible license.

Another specificity of the EUPL is that it is interoperable, without any viral effect in case of static and dynamic linking.[26] This currently depends on European and national law, according to the Computer Programs Directive (Directive 91/250 EEC or 2009/24). Recital 10 of this Directive defines interoperability and recital 15 states that for making two programs interoperable, the code needed can be copied, translated or adapted. For example take program A (new original code just written) and program B (a program licensed by a third party), the developer/licensor of A, who is also a legitimate holder or recipient of B may reproduce in A the needed code from B (e.g. the APIs or the needed data structures from program B) without copyright infringement and without authorization from the copyright holder of B. The licensor of A can do and distribute this without being bonded by conditions or limitations imposed by a licence of program B. This must stay compatible with the normal use of program B and cannot prejudice the legitimate interest of the copyright holder of B.

Unlike the "articles", the directive "recitals" are not transposed as such in national laws. However, recitals are part of European law: they are serving for understanding the scope and rationale of the law, and will be used by the court for interpreting the law, as the case may be. While recitals in EU Directives and Regulations are not considered to have independent legal value, they can expand an ambiguous provision's scope. They cannot restrict an unambiguous provision's scope, but they can be used to determine the nature of a provision, or to adapt it to new circumstances.

It is important to make a distinction between the various flavours of the “Strong Copyleft” concept. According to the GPL/AGPL licensor vision, this means some restrictions and conditions regarding interoperability (due to the theory that linking other software with the covered code creates a combined derivative) and regarding compatibility (since no derivative could be licensed under another license, which may create incompatibilities). The EUPL vision that is depending on the EU law is all the contrary: linking makes no derivatives and when merging source code licensed differently is a necessity, the resulting derivative can be licensed under a compatible license. For some of those, the copyleft is known to be “weaker” (i.e. the MPL), but this has no impact because according to the EUPL the compatible license will prevail when its provisions conflict with those of the EUPL. Since none of the compatible license prohibits the strong reciprocity implemented by the EUPL (obligation to publish and share the source code of derivatives, even distributed through a network) the copyleft resulting from the EUPL can be considered as strong. For this reason, the German lawyer Niklas Plutte created for the EUPL the new category of "Interoperable copyleft licence".[27]